Sample records for asteroids digging soil
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Asteroid Deflection: How, Where and When?
NASA Astrophysics Data System (ADS)
Fargion, D.
2008-10-01
To deflect impact-trajectory of massive and spinning km^3 asteroid by a few terrestrial radiuses one need a large momentum exchange. The dragging of huge spinning bodies in space by external engine seems difficult or impossible. Our solution is based on the landing of multi screw-rockets, powered by mini-nuclear engines, on the body, that dig a small fraction of the soil surface to use as an exhaust propeller, ejecting it vertically in phase among themselves. Such a mass ejection increases the momentum exchange, their number redundancy guarantees the stability of the system. The slow landing (below ≃ 40 cm s^{-1}) of each engine-unity at those very low gravity field, may be achieved by safe rolling and bouncing along the surface. The engine array tuned activity, overcomes the asteroid angular velocity. Coherent turning of the jet heads increases the deflection efficiency. A procession along its surface may compensate at best the asteroid spin. A small skin-mass (about 2×10^4 tons) may be ejected by mini-nuclear engines. Such prototypes may also build first safe galleries for humans on the Moon. Conclusive deflecting tests might be performed on remote asteroids. The incoming asteroid 99942 Apophis (just 2% of km^3) may be deflected safely a few Earth radiuses. Its encounter maybe not just a hazard but an opportunity, learning how to land, to dig, to build and also to nest safe human station inside. Asteroids amplified deflections by gravity swing may be driven into longest planetary journeys, beginning i.e. with the preliminary landing of future missions on Mars' moon-asteroid Phobos or Deimos.
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NASA Technical Reports Server (NTRS)
Youk, G. U.; Whittaker, W. (Red); Volpe, R.
2000-01-01
Perhaps the most promising site for extant life on Mars today is where subsurface water has been maintained. Therefore, searching for underground water will provide a good chance to find evidence of life on Mars. The following are scientific/engineering questions that we want to answer using our approach: (1) Is there subsurface water/ice? How deep is it? How much is there? Is it frozen? (2) What kinds of underground layers exist in the Martian crust? (3) What is the density of Martian soil or regolith? Can we dig into it? Should we drill into it? (4) Can a sudden release of underground water occur if a big asteroid hits Mars? Our approach provides essential information to answer these questions. Moreover, dependence on the water content and depth in soil, not only resultant scientific conclusions but also proper digging/drilling methods, are suggested. 'How much water is in the Martian soil?' There can be several possibilities: (1) high water content that is enough to form permafrost; (2) low water content that is not enough to form permafrost; or (3) different layers with different moisture contents. 'How deep should a rover dig into soil to find water/ice?' The exact size-frequency distribution has not been measured for the soil particles. On-board sensors can provide not only the water content but also the density (or porosity) of Martian soil as a function of depth.
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Kidnapping small icy asteroids in Earth near encounter to harbour life and to deflect trajectory
NASA Astrophysics Data System (ADS)
Fargion, Daniele
2016-07-01
The inter-planetary flight for human being is under danger because of unscreened and lethal solar flare radioactive showers. The screening of the astronauts by huge superconducting magnetic fields is unrealistic by many reasons. On the contrary the ability to reach nearby icy asteroids, to harbour there a complete undergound room where ecological life systems are first set, this goal may offer a later natural and safe currier for future human stations and enterprise. The need to deflect such a small size (a few thousands tons objects) maybe achieved by micro nuclear engines able to dig the asteroid icy skin, to heat and propel the soil by a synchronous jet engine array, bending and driving it to any desired trajectories. The need for such a wide collection of icy asteroid stations, often in a robotic ibernated state, it will offer the safe help station, raft in the wide space sea, where to collect material or energy in long human planetary travels.
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Digging behaviors of radio-tagged black-footed ferrets near Meeteetse, Wyoming, 1981-1984
Biggins, Dean E.; Hanebury, Louis R.; Fagerstone, Kathleen A.
2012-01-01
Intensive radio-tracking during August–December enabled us to collect detailed information on digging behaviors of a small sample of black-footed ferrets (Mustela nigripes) occupying colonies of white-tailed prairie dogs (Cynomys leucurus). A sample of 33 prairie dogs, also radio-tagged, progressively ceased aboveground activity during late summer and fall, presumably as they descended into burrows to hibernate. Most of the time ferrets spent digging was in November–December when >95% of the radio-tagged prairie dogs were inactive, suggesting that digging was primarily to excavate hibernating prey. Although 43.9% of the burrow openings were estimated to be in large mounds, which are common on colonies of white-tailed prairie dogs, all of a sample of 17 deposits of soil (diggings) made by ferrets were excavated at small mounds or nonmounded openings. The average duration of 23 nocturnal sessions of digging by ferrets was 112.2 minutes. A digging session consisted of multiple bouts of soil movement typically lasting about 5 min, and sessions were separated by pauses above- or belowground lasting several minutes. Bouts of moving soil from a burrow involved round-trips of 12.5–30.3 s to remove an average of 35 cm3 of soil per trip. These digging bouts are energetically costly for ferrets. One female moved 16.8 kg of soil an estimated 3.3 m during bouts having a cumulative duration of 178 minutes, removing a soil plug estimated to be 178 cm long. Increasing evidence suggests that some behaviors of ferrets and prairie dogs are coevolutionary responses between this highly specialized predator and its prairie dog prey.
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It! The Secrets of Soil Come and Explore! Discover the amazing world of soils with images and information from the Dig It! The Secrets of Soil exhibit from the Smithsonian's National Museum of Natural and new web content will be added over the coming months including a new soil blog. New Interactives
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Pielström, Steffen; Roces, Flavio
2014-01-01
The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.
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, please email us. Dig It! The Secrets of Soil - Exhibit Activities These activities provide a focused , and learn how to become soil conservationists! NEW Dig It! Educational Materials for Stewardship Week Museum of Natural History, and the Soil Science Society of America. Materials include an educator's guide
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Black-footed ferret digging activity in summer
Eads, David A.; Biggins, Dean E.; Marsh, Dustin; Millspaugh, Joshua J.; Livieri, Travis M.
2012-01-01
Black-footed ferrets (Mustela nigripes) excavate soil from prairie dog (Cynomys spp.) burrows, thereby creating characteristic soil deposits at burrow openings. These soil deposits have been observed only rarely in summer. We monitored adult ferrets during June–October of the years 2007 and 2008 on a 452-ha colony of black-tailed prairie dogs (Cynomys ludovicianus) in the Conata Basin, South Dakota. We located and identified ferret excavations during nighttime spotlight surveys for ferrets and daytime sampling of prairie dog burrow openings around locations where ferrets were located via spotlight. We accumulated 48 observations of in-process or recently completed ferret excavations during spotlight surveys (21 in 2007, 27 in 2008) and located 51 diggings during daytime burrow sampling (25 in 2007, 26 in 2008). We located diggings during 5.5% of spotlight observations, most frequently in July–August. These results collectively suggest ferrets may frequently excavate soil in summer, because prairie dogs frequently use soil to plug burrow openings and tunnels in defense against ferrets. Prairie dogs might frequently destroy soil deposits left by ferrets during summer, thereby reducing detection of diggings by biologists.
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Pielström, Steffen; Roces, Flavio
2014-01-01
The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed. PMID:24748382
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Marcy, Ariel E.; Fendorf, Scott; Patton, James L.; Hadly, Elizabeth A.
2013-01-01
Species ranges are mediated by physiology, environmental factors, and competition with other organisms. The allopatric distribution of five species of northern Californian pocket gophers (Thomomys spp.) is hypothesized to result from competitive exclusion. The five species in this environmentally heterogeneous region separate into two subgenera, Thomomys or Megascapheus, which have divergent digging styles. While all pocket gophers dig with their claws, the tooth-digging adaptations of subgenus Megascapheus allow access to harder soils and climate-protected depths. In a Northern Californian locality, replacement of subgenus Thomomys with subgenus Megascapheus occurred gradually during the Pleistocene-Holocene transition. Concurrent climate change over this transition suggests that environmental factors – in addition to soil – define pocket gopher distributional limits. Here we show 1) that all pocket gophers occupy the subset of less energetically costly soils and 2) that subgenera sort by percent soil clay, bulk density, and shrink-swell capacity (a mineralogical attribute). While clay and bulk density (without major perturbations) stay constant over decades to millennia, low precipitation and high temperatures can cause shrink-swell clays to crack and harden within days. The strong yet underappreciated interaction between soil and moisture on the distribution of vertebrates is rarely considered when projecting species responses to climatic change. Furthermore, increased precipitation alters the weathering processes that create shrink-swell minerals. Two projected outcomes of ongoing climate change—higher temperatures and precipitation—will dramatically impact hardness of soil with shrink-swell minerals. Current climate models do not include factors controlling soil hardness, despite its impact on all organisms that depend on a stable soil structure. PMID:23717675
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Drilling and Digging Techniques for the Early Lunar Outpost
NASA Technical Reports Server (NTRS)
Boles, Walter W.
1992-01-01
The theme of this workshop is lunar resource assessment. Topics include identification, quantification, and location of useful elements on and below the lunar surface. The objective of this paper is to look at another side of the issue--how to remove soil from the stiff lunar-soil matrix once useful deposits are located. The goal of this paper is to cause those who think that digging or excavating on the Moon is a trivial problem to rethink the reasons for their opinions. Another goal is to encourage them to view total reliance upon terrestrial heuristics with suspicion. This paper will focus primarily upon digging.
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Pielström, Steffen; Roces, Flavio
2013-01-01
The Chaco leaf-cutting ant Atta vollenweideri (Forel) inhabits large and deep subterranean nests composed of a large number of fungus and refuse chambers. The ants dispose of the excavated soil by forming small pellets that are carried to the surface. For ants in general, the organisation of underground soil transport during nest building remains completely unknown. In the laboratory, we investigated how soil pellets are formed and transported, and whether their occurrence influences the spatial organisation of collective digging. Similar to leaf transport, we discovered size matching between soil pellet mass and carrier mass. Workers observed while digging excavated pellets at a rate of 26 per hour. Each excavator deposited its pellets in an individual cluster, independently of the preferred deposition sites of other excavators. Soil pellets were transported sequentially over 2 m, and the transport involved up to 12 workers belonging to three functionally distinct groups: excavators, several short-distance carriers that dropped the collected pellets after a few centimetres, and long-distance, last carriers that reached the final deposition site. When initiating a new excavation, the proportion of long-distance carriers increased from 18% to 45% within the first five hours, and remained unchanged over more than 20 hours. Accumulated, freshly-excavated pellets significantly influenced the workers' decision where to start digging in a choice experiment. Thus, pellets temporarily accumulated as a result of their sequential transport provide cues that spatially organise collective nest excavation.
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NASA Astrophysics Data System (ADS)
Shabanova, N. P.; Lebedeva Verba, M. P.; Bykov, A. V.
2014-03-01
The effect of digging activity of little souslik ( Spermophilus pygmaeus Pall.) on the microtopography and soils was studied in the areas with shallow saline groundwater developing under continental conditions for 10.5-12.7 ka. The portion of microtopographic features related to the digging activity was quantified. It was found that the micromounds formed by sousliks appear on recently dried surfaces with shallow saline groundwater. However, their portion in this case is less than 3% because of the poor vegetation and shallow groundwater. Then, with the lowering of the base of erosion and aging of the territory, the zoogenic effect becomes more pronounced. On the first terrace of Khaki Sor (salt lake), the digging activity of sousliks creates the initial heterogeneity of soils and vegetation. The soil cover is composed of the virgin quasigleyed solonchakous solonetzes under the Atriplex-Artemisia santonica association (Gypsic Salic Solonetz (Albic, Ruptic, Oxiaquic, Siltic)) and of the zooturbated solonetzes under the Artemisia santonica-A. lerchiana association (Endosalic Hypogypsic Gypsisol (Sodic, Siltic, Novic)). A comparative analysis of morphology and some chemical properties of virgin and zooturbated soils is given. The soils of souslik-made mounds are strongly mixed, and the structure of their horizons is completely disturbed. They are characterized by an increased total content of salts mainly due to gypsum accumulation. At the same time, the content of toxic salts in the soil profile remains rather high because of their ascending migration from the strongly saline groundwater. On the first terrace, the process of zoogenic amelioration of solonetzes by sousliks is limited and does not affect deep soil layers.
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Digging Movie from Phoenix's Sol 18
NASA Technical Reports Server (NTRS)
2008-01-01
The Surface Stereo Imager on NASA's Phoenix Mars Lander recorded the images combined into this movie of the lander's Robotic Arm enlarging and combining the two trenches informally named 'Dodo' (left) and 'Goldilocks.' The 21 images in this sequence were taken over a period of about 2 hours during Phoenix's Sol 18 (June 13, 2008), or the 18th Martian day since landing. The main purpose of the Sol 18 dig was to dig deeper for learning the depth of a hard underlying layer. A bright layer, possibly ice, was increasingly exposed as the digging progressed. Further digging and scraping in the combined Dodo-Goldilocks trench was planned for subsequent sols. The combined trench is about 20 centimeters (about 8 inches) wide. The depth at the end of the Sol 18 digging is 5 to 6 centimeters (about 2 inches). The Goldilocks trench was the source of soil samples 'Baby Bear' and 'Mama Bear,' which were collected on earlier sols and delivered to instruments on the lander deck. The Dodo trench was originally dug for practice in collecting and depositing soil samples. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver. -
Underground barrier construction apparatus with soil-retaining shield
Gardner, Bradley M.; Smith, Ann Marie; Hanson, Richard W.; Hodges, Richard T.
1998-01-01
An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.
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News from Online: Digging up Earth Day Resources
ERIC Educational Resources Information Center
Coldwell, Bernadette A.
2006-01-01
The soil science and soil chemistry is incorporated into teaching materials for earth day and beyond. It revealed some of the chemical properties of the soil through color and texture and the chemical processes relevant to soils abound, including the carbon and nitrogen cycles in the soil, acidification of soils through acid deposition, leaching…
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Impact-Actuated Digging Tool for Lunar Excavation
NASA Technical Reports Server (NTRS)
Wilson, Jak; Chu, Philip; Craft, Jack; Zacny, Kris; Santoro, Chris
2013-01-01
NASA s plans for a lunar outpost require extensive excavation. The Lunar Surface Systems Project Office projects that thousands of tons of lunar soil will need to be moved. Conventional excavators dig through soil by brute force, and depend upon their substantial weight to react to the forces generated. This approach will not be feasible on the Moon for two reasons: (1) gravity is 1/6th that on Earth, which means that a kg on the Moon will supply 1/6 the down force that it does on Earth, and (2) transportation costs (at the time of this reporting) of $50K to $100K per kg make massive excavators economically unattractive. A percussive excavation system was developed for use in vacuum or nearvacuum environments. It reduces the down force needed for excavation by an order of magnitude by using percussion to assist in soil penetration and digging. The novelty of this excavator is that it incorporates a percussive mechanism suited to sustained operation in a vacuum environment. A percussive digger breadboard was designed, built, and successfully tested under both ambient and vacuum conditions. The breadboard was run in vacuum to more than 2..times the lifetime of the Apollo Lunar Surface Drill, throughout which the mechanism performed and held up well. The percussive digger was demonstrated to reduce the force necessary for digging in lunar soil simulant by an order of magnitude, providing reductions as high as 45:1. This is an enabling technology for lunar site preparation and ISRU (In Situ Resource Utilization) mining activities. At transportation costs of $50K to $100K per kg, reducing digging forces by an order of magnitude translates into billions of dollars saved by not launching heavier systems to accomplish excavation tasks necessary to the establishment of a lunar outpost. Applications on the lunar surface include excavation for habitats, construction of roads, landing pads, berms, foundations, habitat shielding, and ISRU.
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Test Rover Sinks into Prepared Soil
2009-06-30
While a test rover rolls off a plywood surface into a prepared bed of soft soil, rover team members Colette Lohr left and Kim Lichtenberg center eye the wheels digging into the soil and Paolo Bellutta enters the next driving command.
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Phytoremediation of Soil Trace Elements
USDA-ARS?s Scientific Manuscript database
This chapter summarizes research progress in development of phytoremediation technologies. Some soils have become contaminated by trace elements enough to kill plants, inhibit soil organisms, and/or threaten wildlife, humans or the environment. Traditional remediation by dig and haul methods are v...
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A device for measuring soil frost
James H. Patric; Burley D. Fridley
1969-01-01
A water-filled plastic tube buried vertically in the soil in a copper casing permitted repeated observation of frost depth without damaging the sampling site. The device is simple and inexpensive and provides data on soil freezing at least as accurate as direct observation by digging through frozen soil.
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Digging up food: excavation stone tool use by wild capuchin monkeys.
Falótico, Tiago; Siqueira, José O; Ottoni, Eduardo B
2017-07-24
Capuchin monkeys at Serra da Capivara National Park (SCNP) usually forage on the ground for roots and fossorial arthropods, digging primarily with their hands but also using stone tools to loosen the soil and aid the digging process. Here we describe the stone tools used for digging by two groups of capuchins on SCNP. Both groups used tools while digging three main food resources: Thiloa glaucocarpa tubers, Ocotea sp roots, and trapdoor spiders. One explanation for the occurrence of tool use in primates is the "necessity hypothesis", which states that the main function of tool use is to obtain fallback food. We tested for this, but only found a positive correlation between plant food availability and the frequency of stone tools' use. Thus, our data do not support the fallback food hypothesis for the use of tools to access burrowed resources.
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2017-01-17
On Earth, geologists can dig holes and pull up core samples to find out what lies beneath the surface. On Mars, geologists cannot dig holes very easily themselves, but a process has been occurring for billions of years that has been digging holes for them: impact cratering. Impact craters form when an asteroid, meteoroid, or comet crashes into a planet's surface, causing an explosion. The energy of the explosion, and the resulting size of the impact crater, depends on the size and density of the impactor, as well as the properties of the surface it hits. In general, the larger and denser the impactor, the larger the crater it will form. The impact crater in this image is a little less than 3 kilometers in diameter. The impact revealed layers when it excavated the Martian surface. Layers can form in a variety of different ways. Multiple lava flows in one area can form stacked sequences, as can deposits from rivers or lakes. Understanding the geology around impact craters and searching for mineralogical data within their layers can help scientists on Earth better understand what the walls of impact craters on Mars expose. http://photojournal.jpl.nasa.gov/catalog/PIA12328
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NASA Astrophysics Data System (ADS)
Zenkov, S. A.; Lobanov, D. V.
2018-03-01
3D rigid-body model of a bucket of power shovel EK-18 was built using modern CAD-software. Tetrahedral grid with 10-node second-order elements was chosen, and the given model was imported to APM WinMachine - model preparation preprocessor for finite element analysis. The finite element model was based on the geometrical model, imported from KOMPAS-3D to APM Studio. Calculation of stressed-strained state of the bucket was carried out under the forces emerging while digging with “back hoe” equipment. Shift, deformation and tension charts were planned and the most and the least strained areas were pointed out. Wet coherent soil excavation deals with soil adhesion to working bodies of power shovels and leads to reduced performance. The performance decrease is caused by a reduction of useful bucket capacity and partial unloading, increased front resistance to cutting (digging) caused by wet soil adhesion to a working body, increased bucket entry resistance, increased idle time caused by necessity to clean working bodies. Also energy losses increase and quality of work drops because friction forces go up. Friction force occurs while digging and levelling account for 30…70 percent of total digging resistance while performance decreases 1.2…2 times and more. Vibrothermal exposure creates new technological effect which involves a wider humidity range of efficient application and a reduction of friction forces. Disintegrating adhesion bonds with heating requires less driving force from the vibrator. Vibration boosts up heating of the contact layer, which reduces thermal energy losses. However, the question of piezoelectric ceramic actuators location on the excavator bucket needs to be dealt with. The most suitable spots for mounting piezoelectric ceramic devices for reducing soil adhesion to the excavator bucket were defined. Their efficiency is derived from combined (vibrothermal) methods of exposure. Such devices eliminates soil adhesion to the bucket and increases efficiency of using power shovels with wet coherent soils.
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Underground barrier construction apparatus with soil-retaining shield
Gardner, B.M.; Smith, A.M.; Hanson, R.W.; Hodges, R.T.
1998-08-04
An apparatus is described for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment. 17 figs.
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Students Dig Deep in the Mystery Soil Lab: A Playful, Inquiry-Based Soil Laboratory Project
ERIC Educational Resources Information Center
Thiet, Rachel K.
2014-01-01
The Mystery Soil Lab, a playful, inquiry-based laboratory project, is designed to develop students' skills of inquiry, soil analysis, and synthesis of foundational concepts in soil science and soil ecology. Student groups are given the charge to explore and identify a "Mystery Soil" collected from a unique landscape within a 10-mile…
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Device and method for producing a containment barrier underneath and around in-situ buried waste
Gardner, Bradley M.; Smith, Ann M.; Hanson, Richard W.; Hodges, Richard T.
1998-01-01
An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably on which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.
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Device and method for producing a containment barrier underneath and around in-situ buried waste
Gardner, B.M.; Smith, A.M.; Hanson, R.W.; Hodges, R.T.
1998-08-11
An apparatus is described for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably on which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment. 15 figs.
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Digging into Inquiry-Based Earth Science Research
ERIC Educational Resources Information Center
Schultz, Bryan; Yates, Crystal; Schultz, Jayne M.
2008-01-01
To help eighth-grade students experience the excitement of Earth science research, the authors developed an inquiry-based project in which students evaluated and cataloged their campus geology and soils. Following class discussions of rock-weathering and soil-forming processes, students worked in groups to excavate multiple soil pits in the school…
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USDA-ARS?s Scientific Manuscript database
Urban construction removes soil from one site and deposits it at another site as fill material. The purpose of this study was to document characteristics of fill material 20 years after it was deposited, and determine carbon storage in fill and buried soil. The fill material, 0.5 to 0.9 m thick, con...
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Dig In! Hands-On Soil Investigations.
ERIC Educational Resources Information Center
National Science Teachers Association, Arlington, VA.
This guide is geared toward K-4 science teachers, supervisors, and environmental educators. The guide seeks to promote a better understanding and appreciation of soil. Students explore the land around them as they investigate the origins of soil and how it benefits our ecosystems and environment and discover the various habitats characterized by…
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SSSA Outreach: Dig It: The Secrets of Soil, Public Service Announcements, and Science Policy Efforts
NASA Astrophysics Data System (ADS)
Pierzynski, Gary M.; Megonigal, Patrick; Glasener, Karl; Bergfeld, Ellen; Brevik, Eric
2013-04-01
The Soil Science Society of America has invested heavily in two significant outreach efforts to help raise awareness of the soil resource among the general public and with elected officials and relevant federal agencies in Washington DC. Dig It: The Secrets of Soil began as an exhibit at the Smithsonian National Museum of Natural History and ran from July 2008 through January 2010. The exhibit was rich in the use of audio-visual elements and contained a collection of the state soils from all 50 states and numerous interactive displays for all ages. Variations of the exhibit have been on display at three locations outside of Washington DC with the current location being the Bell Museum of Natural History in Minneapolis. The exhibit has been extremely successful in elevating awareness of soils to audiences with little preconceived knowledge on the subject. The success of the Dig It exhibit encouraged SSSA to further invest in three public service announcements that have been widely distributed with 570 downloads and >17,000 views (in English and Spanish) on YouTube and the I "Heart" Soil web site. In addition, I "Heart" Soil stickers were developed and >50,000 have been requested and distributed. Our Science Policy Office has recently been expanded based on evidence of positive impact in Washington DC. The formation of the Congressional Soils Caucus has increased awareness of soils within the House of Representatives and is being expanded to the Senate. A new Urban Lands Coalition has been developed that will greatly expand awareness of the value of soils in urban environments, particularly for elected officials. The Science Policy office organizes member visits with elected officials to advocate for science funding, agency visits to promote awareness of the discipline among a wide ranging of funding sources for research, has had substantial impact on a number of high profile reports, and works closely with allied scientific and professional organizations with common interests.
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NASA Astrophysics Data System (ADS)
Shaw, A.; Arvidson, R.; Bonitz, R.; Carsten, J.; Keller, H.; Lemmon, M.; Mellon, M. T.; Robinson, M.; Trebi-Ollennu, A.; Volpe, R.
2008-12-01
The Phoenix Mars lander has had access to polygonal terrain; specifically, two polygons and a trough. Slopes in the trenches and dump piles created from the interaction of the Phoenix robotic arm (RA) with the soil around its landing site are similar to those seen on previous missions, such as the MER and Viking missions. This indicates similar cohesion and angle of internal friction to previous landing sites. For example, trench slopes typically range from 44-72° and dump pile slopes range from 20-30°. There are at least two very different types of materials at the site: a layer of soil which goes down to several centimeters below the surface and, below that, a layer of icy soil. The RA can easily dig through the top layer of soil, often using 20-30N force. However, when it encounters icy soil, the RA requires tens of scrapes with the lower tungsten carbide blade on its scoop to progress even a few millimeters. To verify soil property parameters, we analyze the normal and shear stresses exerted on the soil by digging, scraping, and rasping with the RA.
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Digging up the Dirt on Soil Safety
ERIC Educational Resources Information Center
Roy, Ken
2010-01-01
Should middle school science teachers be concerned about students bringing in unknown sources of soil to work on in class as the activity suggests? The science is well intended, but is it safe? What are some possible safety issues that might be of concern in dealing with soil samples? This month's column provides several examples of unsuspecting…
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2017 Robotic Mining Competition
2017-05-24
Twin mining robots from the University of Iowa dig in a supersized sandbox filled with BP-1, or simulated Martian soil, during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Physical properties of asteroids in comet-like orbits in the infrared asteroidal survey catalogs
NASA Astrophysics Data System (ADS)
Kim, Y.; Ishiguro, M.; Usui, F.
2014-07-01
Dormant comet and Infrared Asteroidal Survey Catalogs. Comet nucleus is a solid body consisting of dark refractory material and ice. Cometary volatiles sublimate from subsurface layer by solar heating, leaving behind large dust grains on the surface. Eventually, the appearance could turn into asteroidal rather than cometary. It is, therefore, expected that there would be ''dormant comets'' in the list of known asteroids. Over past decade, several ground-based studies have been performed to dig out such dormant comets. One common approach is applying a combination of optical and dynamical properties learned from active comet nucleus to the list of known asteroids. Typical comet nucleus has (i) Tisserand parameter with respect to Jupiter, T_{J}<3, (ii) low geometric albedo, p_{v}<0.1 and (iii) reddish or neutral spectra, similar to P, D, C-type asteroids. Following past ground-based surveys, infrared space missions gave us an opportunity to work on further study of dormant comets. To the present, three infrared asteroidal catalogs taken with IRAS[1], AKARI[2] and WISE[3] are available, providing information of sizes and albedos which are useful to study the physical properties of dormant comets as well as asteroids. Usui et al. (2014) merged three infrared asteroidal catalogs with valid sizes and albedos into single catalog, what they called I-A-W[4]. We applied a huge dataset of asteroids in I-A-W to investigate the physical properties of asteroids in comet-like orbits (ACOs, whose orbits satisfy Q>4.5 au and T_{J}<3). Here we present a study of ACOs in infrared asteroidal catalogs taken with AKARI, IRAS and WISE. In this presentation, we aim to introduce albedo and size properties of ACOs in infrared asteroidal survey catalogs, in combination with orbital and spectral properties from literature. Results and Implications. We summarize our finding and implication as followings: - are 123 ACOs (Q>4.5 au and T_J<3) in I-A-W catalog after rejection of objects with large orbital uncertainties. - Majority (˜80 %) of ACOs have low albedo (p_{v}<0.1), showing similar albedo distribution to active comet nuclei. - Low-albedo ACOs have the cumulative size distribution shallower than that of active comet nuclei. - High-albedo (p_{v}≥0.1) ACOs consist of small (D<3 km) bodies are concentrated in near-Earth space. - We suggest that such high-albedo, small near-Earth asteroids are susceptible to Yarkovsky effect and injected into comet-like orbits.
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ERIC Educational Resources Information Center
Finley, Deborah R.
1991-01-01
Describes a soil lab that can be performed with a minimum of equipment and time, utilizing a lawn, field, or woodlot. Students dig a 1-meter-deep pit and observe the litter and humus layers where most microbial and fungal decomposition occurs. Describes comparing different locations by pH level and concentration of potassium, phosphorous, and…
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NASA Technical Reports Server (NTRS)
Hoffman, John H.; Hedgecock, Jud; Nienaber, Terry; Cooper, Bonnie; Allen, Carlton; Ming, Doug
2000-01-01
The Regolith Evolved Gas Analyzer (REGA) is a high-temperature furnace and mass spectrometer instrument for determining the mineralogical composition and reactivity of soil samples. REGA provides key mineralogical and reactivity data that is needed to understand the soil chemistry of an asteroid, which then aids in determining in-situ which materials should be selected for return to earth. REGA is capable of conducting a number of direct soil measurements that are unique to this instrument. These experimental measurements include: (1) Mass spectrum analysis of evolved gases from soil samples as they are heated from ambient temperature to 900 C; and (2) Identification of liberated chemicals, e.g., water, oxygen, sulfur, chlorine, and fluorine. REGA would be placed on the surface of a near earth asteroid. It is an autonomous instrument that is controlled from earth but does the analysis of regolith materials automatically. The REGA instrument consists of four primary components: (1) a flight-proven mass spectrometer, (2) a high-temperature furnace, (3) a soil handling system, and (4) a microcontroller. An external arm containing a scoop or drill gathers regolith samples. A sample is placed in the inlet orifice where the finest-grained particles are sifted into a metering volume and subsequently moved into a crucible. A movable arm then places the crucible in the furnace. The furnace is closed, thereby sealing the inner volume to collect the evolved gases for analysis. Owing to the very low g forces on an asteroid compared to Mars or the moon, the sample must be moved from inlet to crucible by mechanical means rather than by gravity. As the soil sample is heated through a programmed pattern, the gases evolved at each temperature are passed through a transfer tube to the mass spectrometer for analysis and identification. Return data from the instrument will lead to new insights and discoveries including: (1) Identification of the molecular masses of all of the gases liberated from heated soil samples; (2) Identification of the asteroid soil mineralogy to aid in the selection process for returned samples; (3) Existence of oxygen in the asteroid soil and the potential for in-situ resource utilization (ISRU); and (4) Existence of water and other volatiles in the asteroid soil. Additional information is contained in the original extended abstract.
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Radar observations of asteroid 216 Kleopatra
NASA Technical Reports Server (NTRS)
Ostro, S.; Hudson, R.; Nolan, M.; Margot, J.; Scheeres, D.; Campbell, D.; Magri, C.; Giorgini, J.; Yeomans, D.
2000-01-01
Radar observations of the main-belt, M-class asteroid 216 Kleopatra reveal a dumbbell-shaped object with overall dimensions of 217 kilometers by 94 kilometers by 81 kilometers (+/-25%). The asteroid's surface properties are consistent with a regolith having a metallic composition and a porosity comparable to that of Lunar soil.
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7 CFR 457.135 - Onion crop insurance provisions.
Code of Federal Regulations, 2013 CFR
2013-01-01
... avoirdupois. Lifting or digging. A pre-harvest process in which the onion roots are severed from the soil and the onion bulbs laid on the surface of the soil for drying in the field. Non-storage onions. Onions of... dried to a lower moisture content, are firmer, have more outer layers of paper-like skin, and are darker...
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7 CFR 457.135 - Onion crop insurance provisions.
Code of Federal Regulations, 2014 CFR
2014-01-01
... avoirdupois. Lifting or digging. A pre-harvest process in which the onion roots are severed from the soil and the onion bulbs laid on the surface of the soil for drying in the field. Non-storage onions. Onions of... dried to a lower moisture content, are firmer, have more outer layers of paper-like skin, and are darker...
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7 CFR 457.135 - Onion crop insurance provisions.
Code of Federal Regulations, 2011 CFR
2011-01-01
... digging. A pre-harvest process in which the onion roots are severed from the soil and the onion bulbs laid on the surface of the soil for drying in the field. Non-storage onions. Generally of a Bermuda... that are harvested as a bulb and dried to a lower moisture content, are firmer, have more outer layers...
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7 CFR 457.135 - Onion crop insurance provisions.
Code of Federal Regulations, 2012 CFR
2012-01-01
... digging. A pre-harvest process in which the onion roots are severed from the soil and the onion bulbs laid on the surface of the soil for drying in the field. Non-storage onions. Generally of a Bermuda... that are harvested as a bulb and dried to a lower moisture content, are firmer, have more outer layers...
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Mainbelt asteroids - Dual-polarization radar observations
NASA Technical Reports Server (NTRS)
Ostro, S. J.; Campbell, D. B.; Shapiro, I. I.
1985-01-01
Observations of 20 asteroids in the main belt between Mars and Jupiter provide information about the nature of these objects' surfaces at centimeter-to-kilometer scales. At least one asteroid (Pallas) is extremely smooth at centimeter-to-meter scales. Each asteroid appears much rougher than the moon at some scale between several meters and many kilometers. The range of asteroid radar albedos is very broad and implies substantial variations in porosity or metal concentration (or both). The highest albedo estimate, for the asteroid Psyche, is consistent with a surface having porosities typical of lunar soil and a composition nearly entirely metallic.
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Reduction of granular drag inspired by self-burrowing rotary seeds
NASA Astrophysics Data System (ADS)
Jung, Wonjong; Choi, Sung Mok; Kim, Wonjung; Kim, Ho-Young
2017-04-01
We present quantitative measurements and mat hematical analysis of the granular drag reduction by rotation, as motivated by the digging of Erodium and Pelargonium seeds. The seeds create a motion to dig into soil before germination using their moisture-responsive awns, which are originally helical shaped but reversibly deform to a linear configuration in a humid environment. We show that the rotation greatly lowers the resistance of soil against penetration because grain rearrangements near the intruder change the force chain network. We find a general correlation for the drag reduction by relative slip, leading to a mathematical model for the granular drag of a rotating intruder. In addition to shedding light on the mechanics of a rotating body in granular media, this work can guide us to design robots working in granular media with enhanced maneuverability.
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2014-05-23
CAPE CANAVERAL, Fla. -- The University of North Dakota's robotic miner digs in the simulated Martian soil in the Caterpillar Mining Arena on the final day of NASA's 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-21
CAPE CANAVERAL, Fla. – Competition judges monitor the progress of a robot digging in the simulated Martian soil in the Caterpillar Mining Arena during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-21
CAPE CANAVERAL, Fla. – A robot digs in the simulated Martian soil in the Caterpillar Mining Arena during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-23
CAPE CANAVERAL, Fla. -- Team members prepare their robot to dig in simulated Martian soil in the Caterpillar Mining Arena on the final day of NASA's 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-22
CAPE CANAVERAL, Fla. – Competition judges monitor two team's robots digging in the simulated Martian soil in the Caterpillar Mining Arena during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-21
CAPE CANAVERAL, Fla. – Competition judges monitor the progress of a robot digging in the simulated Martian soil in the Caterpillar Mining Arena during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-21
CAPE CANAVERAL, Fla. – A robot digs in the simulated Martian soil in the Caterpillar Mining Arena during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2012-05-22
CAPE CANAVERAL, Fla. – Participants watch NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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Calculation of Excavation Force for ISRU on Lunar Surface
NASA Technical Reports Server (NTRS)
Zeng, Xiangwu (David); Burnoski, Louis; Agui, Juan H.; Wilkinson, Allen
2007-01-01
Accurately predicting the excavation force that will be encountered by digging tools on the lunar surface is a crucial element of in-situ resource utilization (ISRU). Based on principles of soil mechanics, this paper develops an analytical model that is relatively simple to apply and uses soil parameters that can be determined by traditional soil strength tests. The influence of important parameters on the excavation force is investigated. The results are compared with that predicted by other available theories. Results of preliminary soil tests on lunar stimulant are also reported.
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Making Your School Site an Environmental Smorgasboard.
ERIC Educational Resources Information Center
Carman, Sam
1986-01-01
Describes ways to enhance a school's outdoor facilities to provide more educational opportunities: nesting boxes, ground water monitoring holes, nature's "swamp shop," soil studies, weather stations, wildlife habitat improvement, forestry practices, aquatic resources, archaeological dig sites, horticulture demonstration areas, outdoor…
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Deep 'Stone Soup' Trenching by Phoenix
NASA Technical Reports Server (NTRS)
2008-01-01
Digging by NASA's Phoenix Mars Lander on Aug. 23, 2008, during the 88th sol (Martian day) since landing, reached a depth about three times greater than in any trench Phoenix has excavated. The deep trench, informally called 'Stone Soup' is at the borderline between two of the polygon-shaped hummocks that characterize the arctic plain where Phoenix landed. The lander's Surface Stereo Imager took this picture of Stone Soup trench on Sol 88 after the day's digging. The trench is about 25 centimeters (10 inches) wide and about 18 centimeters (7 inches) deep. When digging trenches near polygon centers, Phoenix has hit a layer of icy soil, as hard as concrete, about 5 centimeters or 2 inches beneath the ground surface. In the Stone Soup trench at a polygon margin, the digging has not yet hit an icy layer like that. Stone Soup is toward the left, or west, end of the robotic arm's work area on the north side of the lander. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver. -
2012-05-22
CAPE CANAVERAL, Fla. – A robotic vehicle takes part in NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A team of competitors works with its machine during NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A team of competitors prepares for a turn in NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A team of competitors prepares for a turn in NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A team of competitors waits for a turn in NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A team of competitors works with its machine during NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A team of competitors works with its machine during NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A team of competitors works with its machine during NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-25
CAPE CANAVERAL, Fla. – A videogame simulates driving excavators during NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2012-05-22
CAPE CANAVERAL, Fla. – A robotic mascot moves among participants during NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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JPL-19680109-SURVEYf-0001-AVC2002083 Surveyor 7 Lands on Moon
1968-01-09
Surveyor 7 was the last of the original series of Surveyor Moon landers. Includes images of scoop digging in the lunar soil. It was the only spacecraft of the series to land in the lunar highland region.
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2017 Robotic Mining Competition
2017-05-24
A robotic miner digs in the mining arena during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Resource Production on the Moon
NASA Technical Reports Server (NTRS)
Landis, Geoffrey A.
2014-01-01
A self-sustaining settlement on the moon, or on other airless bodies such as asteroids, will require the ability to refine desired raw materials from available resources, such as lunar or asteroidal regolith. This work will focus on the example case of pro-duction from lunar regolith. The same process sequences could be used at other locations. Stony asteroids typically have regolith similar to that of the moon, and refining of asteroidal material could use the same techniques, adapted for microgravity. Likewise, Martian rock and soil could also be processed by the techniques discussed here.
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NASA Astrophysics Data System (ADS)
Olgin, J. G.; Güereque, M.; Pennington, D. D.; Everett, A.; Dixon, J. G.; Reyes, A.; Houser, P. I. Q.; Baker, J. A.; Stocks, E.; Ellins, K.
2015-12-01
The Geological Sciences department at the University of Texas at El Paso (UTEP) hosted the EarthTech outreach program - a one-week intensive summer camp for low-income, at-risk high school students. The EarthTech program engaged students in STEM activities from geological and environmental sciences. Developed and led by university student-mentors with guidance from a supervising faculty member, the course engaged Upward Bound students with lectures, interactive projects, and excursions to local ecological preserves and geological sites around El Paso, Texas. Topics covered plant and animal distribution and diversity, water and soil dynamics, evolution and paleontology, geohazards, and planetary science. Field trips were combined with hands-on activities, including activities from DIG Texas teaching modules. The NSF-funded DIG Texas Instructional Blueprints project is organizing vetted, high quality online educational resources and learning activities into teaching modules. The modules follow a storyline and demonstrate congruency with the Next Generation Science Standards. Selected DIG Texas resources were included in the daily curriculum to complement the field trip and other hands-on activities. EarthTech students created ESRI Online GIS story maps in which they showed the locations of the field trips, incorporated photographs they had taken, and provided written reflections about their camp experiences. The DIG Texas project evaluation collected survey and interview data from the university student mentors throughout the week to ascertain the efficacy of the program. This poster presentation will include an overview of the program, including examples of work and evaluation results.
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Flyght Dynamics of Artificial Satellite of the Minor Asteroid
NASA Astrophysics Data System (ADS)
Zakharov, Alexander; Eismont, Natan; Ledkov, Anton; Simonov, Alexander; Pol, Vadim
During last years the scientific interest to the asteroid is constantly growing. It may be explained by different reasons. One of the most important from them is confirmation of the fact that the asteroids present the real hazard to the Earth. The Chelyabinsk event demonstrates strong in support of this statement. Besides, the asteroids exploration promises to supply new data for understanding of the solar system origin and evolution. And the projects aimed to reach this goal have begun from the NASA NEAR mission to Eros. It was the first one when the spacecraft was landed on the surface of the asteroid. The other successive mission was fulfilled by JAXA with Hayabusa spacecraft which has returned to the Earth soil samples of Itokawa asteroid. In the nearest future the mission to RQ 36 asteroid is planned supposing landing and soil samples return. Unavoidable phase of such missions is the spacecraft flight in vicinity of the target asteroid, for example on the asteroid satellite orbit. It should be mentioned that quite visible number of asteroids has geometric form which is far from being sphere. Accordingly the gravity field of such asteroid cannot be presented as the one close to sphere. The problem is that prior to the mission to the asteroid one cannot receive good enough knowledge of its gravity field and even its gravity field constant. In the paper the flight dynamics problem of spacecraft moving along asteroid satellite orbit is explored. It is supposed that the asteroid is comparatively small with diameter (maximum size) about 300 m, like Apophis asteroid has, or less. To approximate the gravity field of asteroid the last is considered as totality of mass points. We assume such approach as more simple and effective as compared with the commonly accepted use of Legendre polynomial expansion. Different orbits near asteroid are analyzed with the sets of orbital parameters determining the size of orbit, its shape and position with respect to the Sun. The goal of this analysis is to understand what initial orbital parameters deliver stability of the orbit in terms of avoiding the collision with the asteroid surface. The orbital heights are calculated which allow to consider the asteroid gravity field as close to the spherical one de-pending on the shape of asteroid. Also maneuvers are estimated necessary for keeping the spacecraft on asteroid satellite orbit and for changing orbital parameters. Taking into account that gravity field parameters of the target asteroids may have pure accuracy it is supposed that spacecraft starts its motion in vicinity of the asteroid from the high enough orbit and then after processing of the tracking data maneuvers are executed to decrease spacecraft altitude. Methods of this procedure optimization are explored.
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NASA Technical Reports Server (NTRS)
Keller, L. P.; Berge, E.
2017-01-01
Regolith grains returned by the Hayabusa mission to asteroid 25143 Itokawa provide the only samples currently available to study the interaction of chondritic asteroidal material with the space weathering environment. Several studies have documented the surface alterations observed on the regolith grains, but most of these studies involved olivine because of its abundance. Here we focus on the rarer Itokawa plagioclase grains, in order to allow comparisons between Itokawa and lunar soil plagioclase grains for which an extensive data set exists.
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29 CFR 780.118 - “Harvesting.”
Code of Federal Regulations, 2013 CFR
2013-07-01
... INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF... fruit, the stripping of bluegrass seed, and the digging up of shrubs and trees grown in a nursery... from their attachment to the soil or otherwise reduced to possession. For example, the processing of...
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29 CFR 780.118 - “Harvesting.”
Code of Federal Regulations, 2011 CFR
2011-07-01
... INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF... fruit, the stripping of bluegrass seed, and the digging up of shrubs and trees grown in a nursery... from their attachment to the soil or otherwise reduced to possession. For example, the processing of...
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29 CFR 780.118 - “Harvesting.”
Code of Federal Regulations, 2010 CFR
2010-07-01
... INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF... fruit, the stripping of bluegrass seed, and the digging up of shrubs and trees grown in a nursery... from their attachment to the soil or otherwise reduced to possession. For example, the processing of...
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29 CFR 780.118 - “Harvesting.”
Code of Federal Regulations, 2012 CFR
2012-07-01
... INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF... fruit, the stripping of bluegrass seed, and the digging up of shrubs and trees grown in a nursery... from their attachment to the soil or otherwise reduced to possession. For example, the processing of...
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29 CFR 780.118 - “Harvesting.”
Code of Federal Regulations, 2014 CFR
2014-07-01
... INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF... fruit, the stripping of bluegrass seed, and the digging up of shrubs and trees grown in a nursery... from their attachment to the soil or otherwise reduced to possession. For example, the processing of...
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Radar observations of asteroid 216 kleopatra
Ostro; Hudson; Nolan; Margot; Scheeres; Campbell; Magri; Giorgini; Yeomans
2000-05-05
Radar observations of the main-belt, M-class asteroid 216 Kleopatra reveal a dumbbell-shaped object with overall dimensions of 217 kilometers by 94 kilometers by 81 kilometers (+/-25%). The asteroid's surface properties are consistent with a regolith having a metallic composition and a porosity comparable to that of lunar soil. Kleopatra's shape is probably the outcome of an exotic sequence of collisional events, and much of its interior may have an unconsolidated rubble-pile structure.
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2012-05-22
CAPE CANAVERAL, Fla. – A team of competitors works with a robotic vehicle taking part in NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. The competition challenges university students to build machines that can collect soil such as the material found on the moon. Working inside the Caterpillar LunArena, the robotic craft dig soil that simulates lunar material. The event is judged by a machine's abilities to collect the soil, its design and operation, size, dust tolerance and its level of autonomy. Photo credit: NASA/Glenn Benson
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2017 Robotic Mining Competition
2017-05-24
The robotic miner from Mississippi State University digs in the mining arena during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition - Activities
2018-05-16
On the third day of NASA's 9th Robotic Mining Competition, May 16, two robot miners dig in the dirt in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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First Dodo Trench with White Layer Visible in Dig Area
NASA Technical Reports Server (NTRS)
2008-01-01
These color images were taken by NASA's Phoenix Mars Lander's Stereo Surface Imager on the ninth Martian day of the mission, or Sol 9 (June 3, 2008). The images of the trench shows a white layer that has been uncovered by the Robotic Arm (RA) scoop and is now visible in the wall of the trench. This trench was the first one dug by the RA to understand the Martian soil and plan the digging strategy. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver. -
A shovel with a perforated blade reduces energy expenditure required for digging wet clay.
Harivanam, Sridhar; Marklin, Richard W; Papanek, Paula E; Cariapa, Vikram
2010-08-01
A shovel with a blade perforated with small holes was tested to see whether a worker would use less whole-body energy to dig wet clay than with a shovel with an opaque blade. A perforated shovel is hypothesized to require less whole-body energy on the basis of adhesion theory; a smaller surface area would require less physical effort to dig and release soil from the blade. The study involved 13 workers from an electric utility who dug wet clay with two 1.5-m long-handled point shovels, which differed only in blade design (perforated and opaque). Oxygen consumption was measured with a portable system while each worker dug wet clay at a self-regulated pace for 10 min. There was no significant difference in number of scoops dug during the 10-min sessions, but workers dug 9.5% more weight of clay with the perforated shovel than with the conventional shovel (404 kg vs. 369 kg, respectively). Furthermore, stable oxygen uptake normalized to weight of participant and to the weight of clay dug revealed that participants expended 11.7% less relative energy per kilogram of clay dug with the perforated shovel. A point shovel with a perforated blade is recommended for digging and shoveling wet clay. However, the extra weight that workers chose to dig with the perforated shovel may increase the loading on the spine and may offset the metabolic advantages. Manual shoveling is a common task, and workers may experience less whole-body and muscle fatigue when using a perforated shovel.
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NASA Technical Reports Server (NTRS)
1977-01-01
VIKING LANDER DIGS A DEEP HOLE ON MARS -- This six-inch-deep, 12- inch-wide, 29-inch-long hole was dug Feb. 12 and 14 by Viking Lander 1 as the first sequence in an attempt to reach a foot beneath the surface of the red planet. The activity is in the same area where Lander 1 acquired its first soil samples last July. The trench was dug by repeatedly backhoeing in a left-right-center pattern. The backhoe teeth produced the small parallel ridges at the far end of the trench (upper left). The larger ridges running the length of the trench are material left behind during the backhoe operation. What appears to be small rocks along the ridges and in the soil at the near end of the trench are really small dirt clods. The clods and the steepness of the trench walls indicate the material is cohesive and behaves something like ordinary flour. After a later sequence, to be performed March 1 and 2, a soil sample will be taken from the bottom of the trench for inorganic soil analysis and later for biology analysis. Information about the soil taken from the bottom of the trench may help explain the weathering process on Mars and may help resolve the dilemma created by Viking findings that first suggest but then cast doubt on the possibility of life in the Martian soil. The trench shown here is a result of one of the most complex command sequences yet performed by the lander. Viking l has been operating at Chryse Planitia on Mars since it landed July 20, 1976.
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Digging the termite way: crowding simple robots to excavate ramification structures
NASA Astrophysics Data System (ADS)
Bardunias, Paul
The complex ramification network that termites excavate in soil in search of resources has been shown to emerge from interactions between individuals during periodic crowding at the tips of tunnels. Excavation in these social insects is carried out by a rotation of termites removing soil from the tip of an expanding tunnel and depositing it back along the tunnel walls. Bristle bots, modified to either rock or turn on contact with soil in an artificial tunnel, were used to replicate this process. As in termites, congestion at tunnel tips leads to the widening and branching of tunnels.
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Geotechnical Tests on Asteroid Simulant Orgueil
NASA Technical Reports Server (NTRS)
Garcia, Alexander D'marco
2017-01-01
In the last 100 years, the global population has more than quadrupled to over seven billion people. At the same time, the demand for food and standard of living has been increasing which has amplified the global water use by nearly eight times from approximately 500 to 4000 cu km per yr from 1900 to 2010. With the increasing concern to sustain the growing population on Earth it is necessary to seek other approaches to ensure that our planet will have resources for generations to come. In recent years, the advancement of space travel and technology has allowed the idea of mining asteroids with resources closer to becoming a reality. During the duration of the internship at NASA Kennedy Space Center, several geotechnical tests were conducted on BP-1 lunar simulant and asteroid simulant Orgueil. The tests that were conducted on BP-1 was to practice utilizing the equipment that will be used on the asteroid simulant and the data from those tests will be omitted from report. Understanding the soil mechanics of asteroid simulant Orgueil will help provide basis for future technological advances and prepare scientists for the conditions they may encounter when mining asteroids becomes reality in the distant future. Distinct tests were conducted to determine grain size distribution, unconsolidated density, and maximum density. Once the basic properties are known, the asteroid simulant will be altered to different levels of compaction using a vibrator table to see how compaction affects the density. After different intervals of vibration compaction, a miniature vane shear test will be conducted. Laboratory vane shear testing is a reliable tool to investigate strength anisotropy in the vertical and horizontal directions of a very soft to stiff saturated fine-grained clayey soil. This test will provide us with a rapid determination of the shear strength on the undisturbed compacted regolith. The results of these tests will shed light on how much torque is necessary to drill through the surface of an asteroid. Most of the known asteroids are believed to be left over material during the formation of the solar system that never accreted to form planets. Asteroids can be found in several groups such as Trojan Asteroids, Near Earth Asteroids (NEAs) and the main asteroid belt. The Trojan Asteroids orbit the 4th and 5th Lagrange points of major planets in the Solar System while the NEA's have orbits that are close to and sometimes intersect with Earths orbit and the Main Asteroid Belt which is found between the orbit of Mars and Jupiter. Gravitational perturbations can alter the orbit of asteroids in the Main Asteroid Belt causing them to move closer to earth causing them to become in the NEA class.
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Robotic Mining Competition - Activities
2018-05-16
On the third day of NASA's 9th Robotic Mining Competition, May 16, judges watch as a robot miner digs in the dirt in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
Members of a college team watch on the monitor as their robot miner digs in the mining arena on the third day of NASA's 9th Robotic Mining Competition, May 16, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Nanoscale Analysis of Space-Weathering Features in Soils from Itokawa
NASA Technical Reports Server (NTRS)
Thompson, M. S.; Christoffersen, R.; Zega, T. J.; Keller, L. P.
2014-01-01
Space weathering alters the spectral properties of airless body surface materials by redden-ing and darkening their spectra and attenuating characteristic absorption bands, making it challenging to characterize them remotely [1,2]. It also causes a discrepency between laboratory analysis of meteorites and remotely sensed spectra from asteroids, making it difficult to associate meteorites with their parent bodies. The mechanisms driving space weathering include mi-crometeorite impacts and the interaction of surface materials with solar energetic ions, particularly the solar wind. These processes continuously alter the microchemical and structural characteristics of exposed grains on airless bodies. The change of these properties is caused predominantly by the vapor deposition of reduced Fe and FeS nanoparticles (npFe(sup 0) and npFeS respectively) onto the rims of surface grains [3]. Sample-based analysis of space weathering has tra-ditionally been limited to lunar soils and select asteroidal and lunar regolith breccias [3-5]. With the return of samples from the Hayabusa mission to asteroid Itoka-wa [6], for the first time we are able to compare space-weathering features on returned surface soils from a known asteroidal body. Analysis of these samples will contribute to a more comprehensive model for how space weathering varies across the inner solar system. Here we report detailed microchemical and microstructal analysis of surface grains from Itokawa.
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Deep 'Stone Soup' Trenching by Phoenix (Stereo)
NASA Technical Reports Server (NTRS)
2008-01-01
Digging by NASA's Phoenix Mars Lander on Aug. 23, 2008, during the 88th sol (Martian day) since landing, reached a depth about three times greater than in any trench Phoenix has excavated. The deep trench, informally called 'Stone Soup' is at the borderline between two of the polygon-shaped hummocks that characterize the arctic plain where Phoenix landed. Stone Soup is in the center foreground of this stereo view, which appears three dimensional when seen through red-blue glasses. The view combines left-eye and right-eye images taken by the lander's Surface Stereo Imager on Sol 88 after the day's digging. The trench is about 25 centimeters (10 inches) wide and about 18 centimeters (7 inches) deep. When digging trenches near polygon centers, Phoenix has hit a layer of icy soil, as hard as concrete, about 5 centimeters or 2 inches beneath the ground surface. In the Stone Soup trench at a polygon margin, the digging has not yet hit an icy layer like that. Stone Soup is toward the left, or west, end of the robotic arm's work area on the north side of the lander. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver. -
Mars Exploration Rover surface operations: driving spirit at Gusev Crater
NASA Technical Reports Server (NTRS)
Leger, Chris; Trebi-Ollennu, Ashitey; Wright, John; Maxwell, Scott; Bonitz, Bob; Biesiadecki, Jeff; Hartman, Frank; Cooper, Brian; Baumgartner, Eric; Maimone, Mark
2005-01-01
Spirit is one of two rovers, that landed on Mars in January 2004 as part of NASA's Mars Exploration Rovers mission. Since then, Spirit has traveled over 4 kilometers accross the Martian surface while investigating rocks and soils, digging trenches to examine the subsurface environment, and climbing hills to reach outcrops of bedrock.
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2012-05-25
CAPE CANAVERAL, Fla. – Robotic vehicles take part in the racing portion of NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Although much of the competition was based on a vehicle's ability to dig soil, the festivities also included head-to-head runs for the robotic craft. Photo credit: NASA/Jim Grossmann
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NASA Technical Reports Server (NTRS)
2008-01-01
This image, acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on Sol 7, the seventh day of the mission (June 1, 2008), shows the so-called 'Knave of Hearts' first-dig test area to the north of the lander. The Robotic Arm's scraping blade left a small horizontal depression above where the sample was taken. Scientists speculate that white material in the depression left by the dig could represent ice or salts that precipitated into the soil. This material is likely the same white material observed in the sample in the Robotic Arm's scoop. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver. -
Phoenix Test Sample Site in Color
NASA Technical Reports Server (NTRS)
2008-01-01
This color image, acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on Sol 7, the seventh day of the mission (June 1, 2008), shows the so-called 'Knave of Hearts' first-dig test area to the north of the lander. The Robotic Arm's scraping blade left a small horizontal depression above where the sample was taken. Scientists speculate that white material in the depression left by the dig could represent ice or salts that precipitated into the soil. This material is likely the same white material observed in the sample in the Robotic Arm's scoop. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver. -
Regolith Advanced Surface Systems Operations Robot (RASSOR)
NASA Technical Reports Server (NTRS)
Mueller, Robert P.; Smith, Jonathan D.; Cox, Rachel E.; Schuler, Jason M.; Ebert, Tom; Nick, Andrew J.
2012-01-01
Regolith is abundant on extra-terrestrial surfaces and is the source of many resources such as oxygen, hydrogen, titanium, aluminum, iron, silica and other valuable materials, which can be used to make rocket propellant, consumables for life support, radiation protection barrier shields, landing pads, blast protection berms, roads, habitats and other structures and devices. Recent data from the Moon also indicates that there are substantial deposits of water ice in permanently shadowed crater regions and possibly under an over burden of regolith. The key to being able to use this regolith and acquire the resources, is being able to manipulate it with robotic excavation and hauling machinery that can survive and operate in these very extreme extra-terrestrial surface environments. In addition, the reduced gravity on the Moon, Mars, comets and asteroids poses a significant challenge in that the necessary reaction force for digging cannot be provided by the robot's weight as is typically done on Earth. Space transportation is expensive and limited in capacity, so small, lightweight payloads are desirable, which means large traditional excavation machines are not a viable option. A novel, compact and lightweight excavation robot prototype for manipulating, excavating, acquiring, hauling and dumping regolith on extra-terrestrial surfaces has been developed and tested. Lessons learned and test results will be presented including digging in a variety of lunar regolith simulant conditions including frozen regolith mixed with water ice.
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Modelling evolution of asteroid's rotation due to the YORP effect
NASA Astrophysics Data System (ADS)
Golubov, Oleksiy; Lipatova, Veronika; Scheeres, Daniel J.
2016-05-01
The Yarkovsky--O'Keefe--Radzievskii--Paddack (or YORP) effect is influence of light pressure on rotation of asteroids. It is the most important factor for evolution of rotation state of small asteroids, which can drastically alter their rotation rate and obliquity over cosmologic timescales.In the poster we present our program, which calculates evolution of ratation state of small asteroids subject to the YORP effect. The program accounts for both axial and obliquity components of YORP, takes into account the thermal inertia of the asteroid's soil, and the tangential YORP. The axial component of YORP is computed using the model by Steinberg and Sari (AJ, 141, 55). The thermal inertia is accounted for in the framework of Golubov et al. 2016 (MNRAS, stw540). Computation of the tangential YORP is based on a siple analytical model, whose applicability is verified via comparison to exact numeric simulations.We apply the program to different shape models of asteroids, and study coupled evolution of their rotation rate and obliquity.
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The Influences of Soil Characteristics on Nest-Site Selection in Painted Turtles (Chrysemys picta)
NASA Astrophysics Data System (ADS)
Page, R.
2017-12-01
A variety of animals dig nests and lay their eggs in soil, leaving them to incubate and hatch without assistance from the parents. Nesting habitat is important for these organisms many of which exhibit temperature dependent sex determination (TSD) whereby the incubation temperature determines the sex of each hatchling. However, suitable nesting habitat may be limited due to anthropogenic activities and global temperature increases. Soil thermal properties are critical to these organisms and are positively correlated with water retention and soil carbon; carbon-rich soils result in higher incubation temperatures. We investigated nest-site selection in painted turtles (Chrysemys picta) inhabiting an anthropogenic pond in south central Pennsylvania. We surveyed for turtle nests and documented location, depth, width, temperature, canopy coverage, clutch size, and hatch success for a total of 31 turtle nests. To address the influence of soil carbon and particle size on nest selection, we analyzed samples collected from: 1) actual nests that were depredated, 2) false nests, incomplete nests aborted during digging prior to nest completion, and 3) randomized locations. Soil samples were separated into coarse, medium, and fine grain size fractions through a stack of sieves. Samples were combusted in a total carbon analyzer to measure weight percent organic carbon. We found that anthropogenic activity at this site has created homogenous, sandy, compacted soils at the uppermost layer that may limit females' access to appropriate nesting habitat. Turtle nesting activity was limited to a linear region north of the pond and was constrained by an impassable rail line. Relative to other studies, turtle nests were notably shallow (5.8±0.9 cm) and placed close to the pond. Compared to false nests and random locations, turtle-selected sites averaged greater coarse grains (35% compared to 20.24 and 20.57%) and less fine grains (47% compared to 59 and 59, respectively). Despite remarkably high soil carbon along the rail line (47.08%) turtles nested here with slightly higher hatch success. We suggest that the turtles are limited to sandy, compact soils with low heat capacities and may compensate for this by also nesting adjacent to the rail line where high soil carbon could increase incubation temperatures.
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A Middle Palaeolithic wooden digging stick from Aranbaltza III, Spain.
Rios-Garaizar, Joseba; López-Bultó, Oriol; Iriarte, Eneko; Pérez-Garrido, Carlos; Piqué, Raquel; Aranburu, Arantza; Iriarte-Chiapusso, María José; Ortega-Cordellat, Illuminada; Bourguignon, Laurence; Garate, Diego; Libano, Iñaki
2018-01-01
Aranbaltza is an archaeological complex formed by at least three open-air sites. Between 2014 and 2015 a test excavation carried out in Aranbaltza III revealed the presence of a sand and clay sedimentary sequence formed in floodplain environments, within which six sedimentary units have been identified. This sequence was formed between 137-50 ka, and includes several archaeological horizons, attesting to the long-term presence of Neanderthal communities in this area. One of these horizons, corresponding with Unit 4, yielded two wooden tools. One of these tools is a beveled pointed tool that was shaped through a complex operational sequence involving branch shaping, bark peeling, twig removal, shaping, polishing, thermal exposition and chopping. A use-wear analysis of the tool shows it to have traces related with digging soil so it has been interpreted as representing a digging stick. This is the first time such a tool has been identified in a European Late Middle Palaeolithic context; it also represents one of the first well-preserved Middle Palaeolithic wooden tool found in southern Europe. This artefact represents one of the few examples available of wooden tool preservation for the European Palaeolithic, allowing us to further explore the role wooden technologies played in Neanderthal communities.
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Auger planting of oak seedlings in northern Arkansas
Eric Heitzman; Adrian Grell
2003-01-01
Planting oak seedlings to regenerate upland oak forests is a promising but untested silvicultural practice in the Ozark Mountains of northern Arkansas. The stony (cherty) soils of the region make it difficult to dig deep planting holes using conventional hand planting tools. In 2001, we planted 1-0 northern red oak and white oak seedlings in 0.5 to 1 acre group...
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ERIC Educational Resources Information Center
Morris, Kirsty
2010-01-01
Geology is not something that people tend to think about in their day-to-day lives; at least, not until it is time to dig out the dusty old rock collection from the back of the science cupboard and teach the rocks and soils unit again! Geology is very much part of people's lives. Geology is about so much more than just looking at rocks and…
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Stereo View of Phoenix Test Sample Site
NASA Technical Reports Server (NTRS)
2008-01-01
This anaglyph image, acquired by NASA's Phoenix Lander's Surface Stereo Imager on Sol 7, the seventh day of the mission (June 1, 2008), shows a stereoscopic 3D view of the so-called 'Knave of Hearts' first-dig test area to the north of the lander. The Robotic Arm's scraping blade left a small horizontal depression above where the sample was taken. Scientists speculate that white material in the depression left by the dig could represent ice or salts that precipitated into the soil. This material is likely the same white material observed in the sample in the Robotic Arm's scoop. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.
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Robotic Mining Competition - Activities
2018-05-16
During the third day of NASA's 9th Robotic Mining Competition, May 16, Al Feinberg, left, with Kennedy Space Center's Communication and Public Engagement, and Kurt Leucht, with Kennedy's Engineering Directorate, provide commentary as robot miners dig in the dirt in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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NASA Technical Reports Server (NTRS)
Blusiu, Julian O.
1997-01-01
Many Future NASA missions will be designed to robotically explore planets, moons and asteroids by collecting soil samples and conducting in-situ analyses to establish ground composition and look for the presence of specific components.
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A Wide-Angle Camera for the Mobile Asteroid Surface Scout (MASCOT) on Hayabusa-2
NASA Astrophysics Data System (ADS)
Schmitz, N.; Koncz, A.; Jaumann, R.; Hoffmann, H.; Jobs, D.; Kachlicki, J.; Michaelis, H.; Mottola, S.; Pforte, B.; Schroeder, S.; Terzer, R.; Trauthan, F.; Tschentscher, M.; Weisse, S.; Ho, T.-M.; Biele, J.; Ulamec, S.; Broll, B.; Kruselburger, A.; Perez-Prieto, L.
2014-04-01
JAXA's Hayabusa-2 mission, an asteroid sample return mission, is scheduled for launch in December 2014, for a rendezvous with the C-type asteroid 1999 JU3 in 2018. MASCOT, the Mobile Asteroid Surface Scout [1], is a small lander, designed to deliver ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context for the returned samples.MASCOT's main objective is to investigate the landing site's geomorphology, the internal structure, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the surface. MASCOT comprises a payload of four scientific instruments: camera, radiometer, magnetometer and hyper-spectral microscope. The camera (MASCOT CAM) was designed and built by DLR's Institute of Planetary Research, together with Airbus DS Germany.
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A Middle Palaeolithic wooden digging stick from Aranbaltza III, Spain
López-Bultó, Oriol; Iriarte, Eneko; Pérez-Garrido, Carlos; Piqué, Raquel; Aranburu, Arantza; Iriarte-Chiapusso, María José; Ortega-Cordellat, Illuminada; Bourguignon, Laurence; Garate, Diego; Libano, Iñaki
2018-01-01
Aranbaltza is an archaeological complex formed by at least three open-air sites. Between 2014 and 2015 a test excavation carried out in Aranbaltza III revealed the presence of a sand and clay sedimentary sequence formed in floodplain environments, within which six sedimentary units have been identified. This sequence was formed between 137–50 ka, and includes several archaeological horizons, attesting to the long-term presence of Neanderthal communities in this area. One of these horizons, corresponding with Unit 4, yielded two wooden tools. One of these tools is a beveled pointed tool that was shaped through a complex operational sequence involving branch shaping, bark peeling, twig removal, shaping, polishing, thermal exposition and chopping. A use-wear analysis of the tool shows it to have traces related with digging soil so it has been interpreted as representing a digging stick. This is the first time such a tool has been identified in a European Late Middle Palaeolithic context; it also represents one of the first well-preserved Middle Palaeolithic wooden tool found in southern Europe. This artefact represents one of the few examples available of wooden tool preservation for the European Palaeolithic, allowing us to further explore the role wooden technologies played in Neanderthal communities. PMID:29590205
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Soil Science Society of America - K-12 Outreach
NASA Astrophysics Data System (ADS)
Lindbo, David L.; Loynachan, Tom; Mblia, Monday; Robinson, Clay; Chapman, Susan
2013-04-01
The Soil Science Society of America created its K12 Committee in 2006 in part to compliment the Dig It! The Secrets of Soil exhibit that opened in July 2008 at the Smithsonian's Institution's Nation Museum of Natural History (of which SSS was a founding sponsor). The committee's work began quickly with a website designed to provide resources for K12 teachers. The first accomplishments included reviewing and posting links to web based information already available to teachers. These links were sorted by subject and grade level to make it easier for teachers to navigate the web and find what they needed quickly. Several presentations and lessons designed for K12 teachers were also posted at this time. Concurrent with this effort a subcommittee review and organized the national teaching standards to show where soils could fit into the overall K12 curriculum. As the website was being developed another subcommittee developed a soils book (Soil! Get the Inside Scoop, 2008) to further compliment the Dig It! exhibit. This was a new endeavor for SSSA having never worked with the non-academic audience in developing a book. Peer-reviews of this book included not only scientist but also students in order to make sure the book was attractive to them. Once the book was published and the website developed it became clear more outreach was needed. SSSA K12 Committee has attended both the National Science Teachers Association (since 2008) the USA Science and Engineering Festival (since 2010) with exhibits and workshops. It has cooperated and contributed to the American Geologic Institutes' Earth Science Week materials with brochures and lesson plans and with National Association of Conservation Districts by providing peer-review and distribution of materials. The most recent developments from the committee include a web redesign that is more student and teacher friendly, the development of a peer-review system to publish K12 Lesson Plans, and finally the publication of a new soils book (Know Soils, Know Life, 2012) for the 8-12th grade audience. It is hoped that Know Soils, Know Life will be used by the Cannon Envirothon and environmental science students and teachers. Future activities planned include a state soils book, teacher's guide for Know Soils, Know Life and development of a searchable digital photo/video library. Overall this committee has been exceedingly productive in its brief 6 year history.
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Search for Dormant Comets in Near-Earth Space
NASA Astrophysics Data System (ADS)
Kim, Yoonyoung
2013-06-01
It is considered that comets have been injected into near-Earth space from outer region (e.g. Kuiper-belt region), providing rich volatile and organic compounds to the earth. Some comets are still active while most of them are dormant with no detectable tails and comae. Here we propose to make a multi-band photometric observation of near-Earth objects (NEOs) with comet-like orbits. We select our targets out of infrared asteroidal catalogs based on AKARI and WISE observations. With a combination of taxonomic types by Subaru observation and albedos by AKARI or WISE, we aim to dig out dormant comet candidates among NEOs. Our results will provide valuable information to figure out the dynamical evolution and fate of comets. We would like to emphasize that this is the first taxonomic survey of dormant comets to utilize the infrared data archive with AKARI and WISE.
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NASA Technical Reports Server (NTRS)
2004-01-01
This image shows the Mars Exploration Rover Spirit's view from its new location inside the shallow depression dubbed 'Laguna Hollow.' To get a better look at the soil making up the hollow, Spirit drove forward a bit, wiggled its wheels, then turned and backed up. The result - a scrape on the floor and a clod of dirt stuck on one of Spirit's wheels - told scientists that the soil is sticky and reminiscent of that observed at the airbag drag mark nicknamed 'Magic Carpet.' Spirit will further investigate this disturbed patch of soil with its robotic arm beginning today (Feb. 19, 2004). It will also dig a trench at 'Laguna Hollow' with one of its wheels. This fish-eye image was taken by the rover's hazard-avoidance camera.
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Childhood exposure to Libby amphibole during outdoor activities.
Ryan, Patrick H; LeMasters, Grace K; Burkle, Jeffrey; Lockey, James E; Black, Brad; Rice, Carol
2015-01-01
Residents of Libby, MT were exposed to amphibole asbestos through multiple environmental pathways. Previous exposure characterization has primarily relied on qualitative report of these exposure activities. The objectives of this study were to describe available data from the US EPA preremediation actions for Libby amphibole (LA) exposure in Libby, MT and develop an approach to characterize outdoor residential exposure to LA among children. Homes in Libby, MT included in the US EPA preremediation Contaminant Screening Survey (CSS) were categorized by the presence of interior and/or exterior visible vermiculite and concentrations of LA were measured in samples of dust and soil. Airborne exposure to LA while digging/gardening, raking, and mowing were estimated using US EPA activity-based sampling (ABS) results. Residential histories and frequency/duration of childhood activities were combined with ABS to demonstrate the approach for estimating potential exposure. A total of 3154 residential properties participated in the CSS and 44% of these had visible exterior vermiculite. Airborne concentrations of LA where there was visible vermiculite outdoors were 3-15 times higher during digging/gardening, raking, and mowing activities compared with homes without visible outdoor vermiculite. Digging and gardening activities represented the greatest contribution to estimated exposures and 73% of the participants reported this activity before the age of 6 years. This methodology demonstrated the use of historical preremediation data to estimate residential exposures of children for specific activities. Children younger than age 6 years may have been exposed to LA while digging/gardening, especially at homes where there is visible outdoor vermiculite. This approach may be extended to other activities and applied to the entire cohort to examine health outcomes.
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Constraints on Exposure Ages of Lunar and Asteroidal Regolith Particles
NASA Technical Reports Server (NTRS)
Berger, Eve L.; Keller, Lindsay P
2014-01-01
Mineral grains in lunar and asteroidal regolith samples provide a unique record of their interaction with the space environment. Exposure to the solar wind results in implantation effects that are preserved in the rims of grains (typically the outermost 100 nm), while impact processes result in the accumulation of vapor-deposited elements, impact melts and adhering grains on particle surfaces. These processes are collectively referred to as space weathering. A critical element in the study of these processes is to determine the rate at which these effects accumulate in the grains during their space exposure. For small particulate samples, one can use the density of solar flare particle tracks to infer the length of time the particle was at the regolith surface (i.e., its exposure age). We have developed a new technique that enables more accurate determination of solar flare particle track densities in mineral grains <50 micron in size that utilizes focused ion beam (FIB) sample preparation combined with transmission electron microscopy (TEM) imaging. We have applied this technique to lunar soil grains from the Apollo 16 site (soil 64501) and most recently to samples from asteroid 25143 Itokawa returned by the Hayabusa mission. Our preliminary results show that the Hayabusa grains have shorter exposure ages compared to typical lunar soil grains. We will use these techniques to re-examine the track density-exposure age calibration from lunar samples reported by Blanford et al. (1975).
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Nine Galileo Views in Exaggerated Color of Main-Belt Asteroid Ida
NASA Technical Reports Server (NTRS)
1997-01-01
This set of color images of asteroid 243 Ida was taken by the imaging system on the Galileo spacecraft as it approached and raced past the asteroid on August 28, 1993. These images were taken through the 4100-angstrom (violet), 7560-angstrom (infrared) and 9680- angstrom (infrared) filters and have been processed to show Ida in exaggerated color to bring out subtle color contrasts caused by small variations in composition and surface microtexture of the asteroid's soil. In natural color Ida appears gray with slight overtones of red or brown. Stark shadows portray Ida's irregular shape, which changes its silhouetted outline when seen from different angles. More subtle shadings reveal surface topography (such as craters) and differences in the physical state and composition of the soil ('regolith'). Note in particular the color differences associated with the rims and floors of certain impact craters, which may have excavated to layers of slightly differing composition or may have ingested material from impactors of different compositions. Analysis of the images show that Ida is 58 kilometers long and 23 kilometers wide (36 x 14 miles). Ida is the first asteroid discovered to have a natural satellite, Dactyl (not shown here). Ida and Dactyl are heavily cratered by impacts with smaller asteroids and comets, including some of the same populations of small objects that bombard Earth. These data, combined with reflectance spectra from Galileo's near-infrared mapping spectrometer, may allow scientists to determine whether Ida is a relatively unaltered primitive object made of material condensed from the primordial Solar Nebula at the origin of the Solar System or whether it has been altered by strong heating--evidence interpreted so far suggests that Ida is a piece of a larger object that has been severely heated. Whereas heating and melting of large planets is well understood, the cause of heating of small asteroids is more enigmatic--it may have involved exotic processes that occurred only for a short time after the birth of the Sun and its planets.
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Data Collection with Vehicular-Based Systems - Pole Mountain, WY
2012-09-01
demonstration site (Billings et al., 2010) and a second demonstration at Camp Butner ( Pasion et al., 2012). To date, testing of these approaches has...determine dig-list order using the DigZilla tool ( Pasion et al., 2012). The DigZilla analysis used all three polarizabilities. An initial stop-dig point...last TOI recovered on the very last dig. The production team used the automated method of Pasion et al., (2012) for determining the stop-dig point
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Photopolarimetric observations of the minor planet Flora.
NASA Technical Reports Server (NTRS)
Veverka, J.
1971-01-01
Review of the rotation period, phase coefficients, and polarization curve of the unusual asteroid Flora. It is an almost spherical asteroid whose period of rotation is probably 13.6 h, but may be only one half of this. Its surface layer consists of a dark material resembling lunar surface soil, but since the polarization curves of Flora and the moon, though generally similar, are not identical the surface of Flora must differ somewhat either in composition or in texture from that of the moon.
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Looking into the evolution of granular asteroids in the Solar System
NASA Astrophysics Data System (ADS)
Sánchez, Paul; Scheeres, Daniel; Hirabayashi, Masatoshi; Tardivel, Simon
2017-06-01
By now it has been accepted that most of the small asteroids in the Solar System are granular aggregates kept together by gravitational and possibly, cohesive forces. These aggregates can form, deform and disrupt over millennia subjected to different internal and external factors that would ultimately determine how they evolve over time. Parameters such as porosity, cohesive and tensile strength, angles of friction, particle size distributions, stress states, heterogeneity and yield criteria among others, determine how these granular systems will react when subjected to different, changing, external factors. These external factors include solar photon momentum, gravitational tides, micro- and macro-impacts and are believed to have produced and shaped the current asteroid population. In our research we use a combination of Soil Mechanics theory, Soft-Sphere Discrete Element Method (SSDEM) Simulations and Orbital Mechanics in order to understand how simulated, homogeneous and heterogeneous, ellipsoidal and spherical gravitational aggregates, a crude but useful representation of an asteroid, evolve when rotated to the point of disruption. Then, we compare our results to the shapes of observed asteroids as well as to the disruption patterns of a few active asteroids. Our results lead us to believe that the different shapes of observed asteroids as well as their unique disruption patterns could give us clues about their internal structure, strength and geophysical properties in general.
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NASA Technical Reports Server (NTRS)
Noguchi, T.; Nakamura, T.; Zolensky, Michael E.; Tanaka, M.; Hashimoto, T.; Konno, M.; Nakato, A.; Ogami, T.; Fujimura, A.; Abe, M.;
2011-01-01
Surface materials on airless solar system bodies exposed to interplanetary space are gradually changed their visible to near-infrared reflectance spectra by the process called "space weathering", which makes the spectra darker and redder. Hapke et al. proposed a model of space weathering: vapor deposition of nanophase reduced iron (npFe(sup 0)) on the surfaces of the grains within the very surface of lunar regolith. This model has been proved by detailed observation of the surfaces of the lunar soil grains by transmission electron microscope (TEM). They demonstrated that npFe(sup 0) was formed by a combination of vapor deposition and irradiation effects. In other words, both micrometeorite impacts and irradiation by solar wind and galactic cosmic ray play roles on the space weathering on the Moon. Because there is a continuum of reflectance spectra from those of Q-type asteroids (almost the same as those of ordinary chondrites) to those of S-type asteroids, it is strongly suggested that reflectance spectra of asteroids composed of ordinary chondrite-like materials were modified over time to those of S-type asteroids due to space weathering. It is predicted that a small amount of npFe(sup 0) on the surface of grains in the asteroidal regolith composed of ordinary chondrite-like materials is the main agent of asteroidal space weathering.
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NASA Technical Reports Server (NTRS)
2004-01-01
The Mars Exploration Rover Opportunity dragged one of its wheels back and forth across the sandy soil at Meridiani Planum to create a hole (bottom of image) measuring approximately 50 centimeters (19.7 inches) long by 20 centimeters (7.9 inches) wide by 9 centimeters (3.5 inches) deep. The rover's instrument deployment device, or arm, will begin studying the fresh soil at the bottom of this trench later today for clues to its mineral composition and history. Scientists chose this particular site for digging because previous data taken by the rover's miniature thermal emission spectrometer indicated that it contains crystalline hematite, a mineral that sometimes forms in the presence of water. The brightness of the newly-exposed soil is thought to be either intrinsic to the soil itself, or a reflection of the Sun. The rock outcrop lining the inner edge of the small crater encircling the rover and lander can be seen on the horizon. This fish-eye image was taken by the rover's hazard-avoidance camera.
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NASA Astrophysics Data System (ADS)
Abakumov, Evgeny
2016-04-01
Physical properties of the soils of the cold environments are underestimated. Soil and permafrost border and active layer thickness are the key classification indicators for the polar soils. That is why electrophysical research has been conducted with aim to determine the soil-permafrost layer heterogeneity and the depth of the uppermost permafrost layer on examples of selected plots in Antarctic region and Russian Arctic. The electric resistivity (ER) was measured directly in the soil profiles using the vertical electrical sounding (VERS) method, which provides data on the changes in the electrical resistivity throughout the profile from the soil surface without digging pits or drilling. This method allows dividing the soil layer vertically into genetic layers, which are different on main key properties and characteristics Different soil layers have different ER values, that is why the sharp changes in ER values in soil profile can be interpreted as results of transition of one horizon to another. In our study, the resistivity measurements were performed using four-electrode (AB + MN) arrays of the AMNB configuration with use of the Schlumberger geometry. A Landmapper ERM-03 instrument (Landviser, USA) was used for the VES measurements in this study. Electrodes were situated on the soil surface, distance between M and N was fixes, while distance from A to B were changed during the sounding. Vertical Electrical Resistivity Soundings (VERS) using Schlumberger array were carried out at stations, situated on the different plots of terrestrial ecosystems of Arctic and Antarctic. The resistance readings at every VERS point were automatically displayed on the digital readout screen and then written down on the field note book. The soils had been 'sounded' thoroughly and found to vary between 5 cm and 3-5 m in A-B distances. It was shown that use of VES methodology in soil survey is quite useful for identification of the permafrost depth without digging of soil pit. This method allow identify soil heterogeneity, because the ER values are strongly affected by soil properties and intensively changes on the border of different geochemical regimes, i.e. on the border of active layer and permafrost. VES data obtained show that the upper border of the permafrost layer coincides with that border, which were identified in field on the base of soil profile morphology. The VERS method also can used for identification of Gleyic, Histic and Podzolic layers. It has been also shown that permafrost layer is less homogenous in upper part of permafrost, than in lower one. It is caused by number of cracks, channels and other paths of dissolved organic matter and iron containing compounds migration. VES methodology is useful for preliminary soil survey in the regions with permafrost affected soil cover. It is also can be applied for detalization of soil-permafrost layer stratification in field soil pits.
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A new mechanism for the formation of regolith on asteroids
NASA Astrophysics Data System (ADS)
Delbo, Marco; Libourel, Guy; Wilkerson, Justin; Murdoch, Naomi; Michel, Patrick; Ramesh, Kt; Ganino, Clement; Verati, Chrystele; Marchi, Simone
2014-11-01
The soil of asteroids, like that of the Moon, and other rocky, airless bodies in the Solar System, is made of a layer of pebbles, sand, and dust called regolith.Previous works suggested that the regolith on asteroids is made from material ejected from impacts and re-accumulated on the surface and from surface rocks that are broken down by micrometeoroid impacts. However, this regolith formation process has problems to explain the regolith on km-sized and smaller asteroids: it is known that impact fragments can reach escape velocities and breaks free from the gravitational forces of these small asteroids, indicating the impact mechanism is not the dominant process for regolith creation. Other studies also reveal that there is too much regolith on small asteroids’ surfaces to have been deposited there solely by impacts over the millions of years of asteroids’ evolution.We proposed that another process is capable of gently breaking rocks at the surface of asteroids: thermal fatigue by temperature cycling. As asteroids spin about their rotation axes, their surfaces go in and out of shadow resulting in large surface temperature variations. The rapid heating and cooling creates thermal expansion and contraction in the asteroid material, initiating cracking and propagating existing cracks. As the process is repeated over and over, the crack damage increases with time, leading eventually to rock fragmentation (and production of new regolith).To study this process, in the laboratory, we subjected meteorites, used as asteroid material analogs, to 37 days of thermal cycles similar to those occurring on asteroids. We measured cracks widening at an average rate of 0.5 mm/y. Some fragments were also produced, indicating meteorite fragmentation. To scale our results to asteroid lifetime, we incorporated our measurements into a fracture model and we deduced that thermal cycling is more efficient than micrometeorite bombardment at fragmenting rock over millions of years on asteroids (see Delbo et al. 2014. Nature 508, 233-236).This work was supported by the French Agence National de la Recherche (ANR) SHOCKS,
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Dermatology Interest Groups in Medical Schools.
Quirk, Shannon K; Riemer, Christie; Beers, Paula J; Browning, Richard J; Correa, Mark; Fawaz, Bilal; Lehrer, Michael; Mounessa, Jessica; Lofgreen, Seth; Oetken, Tara; Saley, Taylor P; Tinkey, Katherine; Tracey, Elisabeth H; Dellavalle, Robert; Dunnick, Cory
2016-07-15
Involvement in a Dermatology Interest Group (DIG) allows students to learn about dermatology, partake in service projects, get involved in research, and ask questions about the application process for residency programs. In this article, we review the activities and member involvement of DIGs from 11 medical schools. To our knowledge, this is the first descriptive analysis of DIGs across the United States. This comparison of DIGs is not only potentially helpful for medical schools interested in establishing a DIG, but it also offers insight into how previously established DIGs could improve and have a greater impact both in individual medical schools and in the community at-large.
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Zhang, Jie; Pekosz, Andrew; Lamb, Robert A.
2000-01-01
Influenza viruses encoding hemagglutinin (HA) and neuraminidase (NA) glycoproteins with deletions in one or both cytoplasmic tails (HAt− or NAt−) have a reduced association with detergent-insoluble glycolipids (DIGs). Mutations which eliminated various combinations of the three palmitoylation sites in HA exhibited reduced amounts of DIG-associated HA in virus-infected cells. The influenza virus matrix (M1) protein was also found to be associated with DIGs, but this association was decreased in cells infected with HAt− or NAt− virus. Regardless of the amount of DIG-associated protein, the HA and NA glycoproteins were targeted primarily to the apical surface of virus-infected, polarized cells. The uncoupling of DIG association and apical transport was augmented by the observation that the influenza A virus M2 protein as well as the influenza C virus HA-esterase-fusion glycoprotein were not associated with DIGs but were apically targeted. The reduced DIG association of HAt− and NAt− is an intrinsic property of the glycoproteins, as similar reductions in DIG association were observed when the proteins were expressed from cDNA. Examination of purified virions indicated reduced amounts of DIG-associated lipids in the envelope of HAt− and NAt− viruses. The data indicate that deletion of both the HA and NA cytoplasmic tails results in reduced DIG association and changes in both virus polypeptide and lipid composition. PMID:10775599
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The Impact of Diffuse Ionized Gas on Emission-line Ratios and Gas Metallicity Measurements
NASA Astrophysics Data System (ADS)
Zhang, Kai; Yan, Renbin; MaNGA Team
2016-01-01
Diffuse Ionized Gas (DIG) is prevalent in star-forming galaxies. Using a sample of galaxies observed by MaNGA, we demonstrate how DIG in star-forming galaxies impact the measurements of emission line ratios, hence the gas-phase metallicity measurements and the interpretation of diagnostic diagrams. We demonstrate that emission line surface brightness (SB) is a reasonably good proxy to separate HII regions from regions dominated by diffuse ionized gas. For spatially-adjacent regions or regions at the same radius, many line ratios change systematically with emission line surface brightness, reflecting a gradual increase of dominance by DIG towards low SB. DIG could significantly bias the measurement of gas metallicity and metallicity gradient. Because DIG tend to have a higher temperature than HII regions, at fixed metallicity DIG displays lower [NII]/[OII] ratios. DIG also show lower [OIII]/[OII] ratios than HII regions, due to extended partially-ionized regions that enhance all low-ionization lines ([NII], [SII], [OII], [OI]). The contamination by DIG is responsible for a substantial portion of the scatter in metallicity measurements. At different surface brightness, line ratios and line ratio gradients can differ systematically. As DIG fraction could change with radius, it can affect the metallicity gradient measurements in systematic ways. The three commonly used strong-line metallicity indicators, R23, [NII]/[OII], O3N2, are all affected in different ways. To make robust metallicity gradient measurements, one has to properly isolate HII regions and correct for DIG contamination. In line ratio diagnostic diagrams, contamination by DIG moves HII regions towards composite or LINER-like regions.
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Characterization of soils containing adipocere.
Fiedler, S; Schneckenberger, K; Graw, M
2004-11-01
The formation of adipocere (commonly known as grave wax), a spontaneous inhibition of postmortem changes, has been extensively analyzed in forensic science. However, soils in which adipocere formation occurs have never been described in detail. Therefore, this study is intended as a first step in the characterization of soils containing adipocere. Two grave soils (Gleyic Anthrosols) that prevent the timely reuse of graves due to the occurrence of adipocere and a control soil (Gleyic Luvisol) were selected from a cemetery in the Central Black Forest (Southwest Germany). Descriptions of soil morphology and a wide assay of physical, chemical, and microbiologic soil characteristics were accomplished. In contrast to the control soil, the grave soils were characterized by lower bulk density and pH. The degradation of the soil structure caused by digging led to a higher water table and the expansion of the reducing conditions in the graves where the prevalent absence of oxygen in range of the coffins inhibited decomposition processes. Although the formation of adipocere led to the conservation of the buried corpses, phosphorus, dissolved organic carbon, and cadavarine leaching from the graves was observed. Microbial biomass and microbial activity were higher in the control soil and hence reflected the inert character of adipocere. The study results clearly show the need for additional approaches in forensic, pedologic, and microbiologic research.
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2012-05-22
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center Visitor Complex in Florida, college students arrive for NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. Photo credit: NASA/Frankie Martin
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Magnetic Particles Are Found In The Martian Atmosphere
NASA Technical Reports Server (NTRS)
1976-01-01
The dark bullseye pattern seen at the top of Viking l's camera calibration chart indicates the presence of magnetic particles in the fine dust in the Martian atmosphere. A tiny magnet is mounted at that spot to catch wind-borne magnetic particles. The particles may have been tossed into the atmosphere surrounding the spacecraft at the time of landing and during the digging and delivery of the Mars soil sample by the surface sampler scoop. This picture was taken August 4.
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NASA Astrophysics Data System (ADS)
Jaumann, Ralf; Bibring, Jean-Pierre; Glassmeier, Karl-Heinz; Grott, Matthias; Ho, Tra-Mi; Ulamec, Stepahn; Schmitz, Nicole; Auster, Ulrich; Biele, Jens; Kuninaka, Hitoshi; Okada, Tatsuaki; Yoshikawa, Makoto; Watanabe, Sei-ichhiro; Fujimoto, Masaki; Spohn, Tilman; Koncz, Alexander; Michaelis, Harald
2014-05-01
MASCOT, a Mobile Asteroid Surface Scout, will support JAXA's Hayabusa 2 mission to investigate the C-type asteroid 1999 JU3 (1). The German Aer-ospace Center (DLR) develops MASCOT with contributions from CNES (France) (2,3). Main objective is to in-situ map the asteroid's geomorpholo-gy, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the sur-face in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples. MASCOT comprises a payload of four scientific in-struments: camera, radiometer, magnetometer and hyperspectral microscope. C- and D-type asteroids hold clues to the origin of the solar system, the for-mation of planets, the origins of water and life on Earth, the protection of Earth from impacts, and resources for future human exploration. C- and D-types are dark and difficult to study from Earth, and have only been glimpsed by spacecraft. While results from recent missions (e.g., Hayabusa, NEAR (4, 5, 6)) have dramatically increased our understanding of asteroids, important questions remain. For example, characterizing the properties of asteroid regolith in-situ would deliver important ground truth for further understanding telescopic and orbital observations and samples of such aster-oids. MASCOT will descend and land on the asteroid and will change its position two times by hopping. This enables measurements during descent, at the landing and hopping positions #1-3, and during hopping. References: (1) Vilas, F., Astronomical J. 1101-1105, 2008; (2) Ulamec, S., et al., Acta Astronautica, Vol. 93, pp. 460-466; (3) Jaumann et al., 45th LPSC, Houston; (4) Special Issue, Science, Vol. 312 no. 5778, 2006; (5) Special Issue Science, Vol. 333 no. 6046, 2011. (6) Bell, L., Mitton, J-., Cambridge Univ. Press, 2002.
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NASA Astrophysics Data System (ADS)
Jaumann, Ralf; Bibring, Jean-Pierre; Glassmeier, Karl-Heinz; Grott, Matthias; Ho, Tra-Mie; Ulamec, Stephan; Schmitz, Nicole; Auster, Hans-Ulrich; Biele, Jens; Kuninaka, Hitoshi; Okada, Tatsuaki; Yoshikawa, Makoto; Watanabe, Sei-ichhiro; Fujimoto, Masaki; Spohn, Tilman
2013-04-01
Mascot, a Mobile Asteroid Surface Scout, will support JAXA's Hayabusa 2 mission to investigate the C-type asteroid 1999 JU3 (1). The German Aero-space Center (DLR) develops Mascot with contributions from CNES (France) (2). Main objective is to in-situ map the asteroid's geomorphology, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the surface in order to provide ground truth for the orbiter remote measurements, sup-port the selection of sampling sites, and provide context information for the returned samples. Mascot comprises a payload of four scientific instruments: camera, radiometer, magnetometer and hyperspectral microscope. C- and D-type asteroids hold clues to the origin of the solar system, the formation of planets, the origins of water and life on Earth, the protection of Earth from impacts, and resources for future human exploration. C- and D-types are dark and difficult to study from Earth, and have only been glimpsed by spacecraft. While results from recent missions (e.g., Hayabusa, NEAR (3, 4, 5)) have dramatically increased our understanding of asteroids, important questions remain. For example, characterizing the properties of asteroid reg-olith in-situ would deliver important ground truth for further understanding telescopic and orbital observations and samples of such asteroids. Mascot will descend and land on the asteroid and will change its position two times by hopping. This enables measurements during descent, at the landing and hopping positions #1-3, and during hopping. References: (1) Vilas, F., Astronomical J. 1101-1105, 2008; (2) Ulamec, S., et al., COSPAR, General Assembly, Mysore/India, 2012; (3) Special Issue, Science, Vol. 312 no. 5778, 2006; (4) Special Issue Science, Vol. 333 no. 6046, 2011; (5) Bell, L., Mitton, J-., Cambridge Univ. Press, 2002.
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Molecular identification of Coccidioides spp. in soil samples from Brazil
2011-01-01
Background Since 1991 several outbreaks of acute coccidioidomycosis (CM) were diagnosed in the semi-arid Northeast of Brazil, mainly related to disturbance of armadillo burrows caused by hunters while digging them for the capture of these animals. This activity causes dust contaminated with arthroconidia of Coccidioides posadasii, which, once inhaled, cause the mycosis. We report on the identification of C. posadasii in soil samples related to outbreaks of CM. Results Twenty four soil samples had their DNA extracted and subsequently submitted to a semi-nested PCR technique using specific primers. While only 6 (25%) soil samples were positive for C. posadasii by mice inoculation, all (100%) were positive by the molecular tool. Conclusion This methodology represents a simple, sensitive and specific molecular technique to determine the environmental distribution of Coccidioides spp. in endemic areas, but cannot distinguish the species. Moreover, it may be useful to identify culture isolates. Key-words: 1. Coccidioidomycosis. 2. Coccidioides spp. 3. C. posadasii. 4. Semi-arid. 5. Semi-nested PCR PMID:21575248
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Highest Resolution Topography of 433 Eros and Implications for MUSES-C
NASA Technical Reports Server (NTRS)
Cheng, A. F.; Barnouin-Jha, O.
2003-01-01
The highest resolution observations of surface morphology and topography at asteroid 433 Eros were obtained by the Near Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft on 12 February 2001, as it landed within a ponded deposit on Eros. Coordinated observations were obtained by the imager and the laser rangefinder, at best image resolution of 1 cm/pixel and best topographic resolution of 0.4 m. The NEAR landing datasets provide unique information on rock size and height distributions and regolith processes. Rocks and soil can be distinguished photometrically, suggesting that bare rock is indeed exposed. The NEAR landing data are the only data at sufficient resolution to be relevant to hazard assessment on future landed missions to asteroids, such as the MUSES-C mission which will land on asteroid 25143 (1998 SF36) in order to obtain samples. In a typical region just outside the pond where NEAR landed, the areal coverage by resolved positive topographic features is 18%. At least one topographic feature in the vicinity of the NEAR landing site would have been hazardous for a spacecraft.
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Thermal and Electrical Conductivity Probe for Phoenix Mars Lander
NASA Technical Reports Server (NTRS)
2007-01-01
NASA's Phoenix Mars Lander will assess how heat and electricity move through Martian soil from one spike or needle to another of a four-spike electronic fork that will be pushed into the soil at different stages of digging by the lander's Robotic Arm. The four-spike tool, called the thermal and electrical conductivity probe, is in the middle-right of this photo, mounted near the end of the arm near the lander's scoop (upper left). In one type of experiment with this tool, a pulse of heat will be put into one spike, and the rate at which the temperature rises on the nearby spike will be recorded, along with the rate at which the heated spike cools. A little bit of ice can make a big difference in how well soil conducts heat. Similarly, soil's electrical conductivity -- also tested with this tool -- is a sensitive indicator of moisture in the soil. This device adapts technology used in soil-moisture gauges for irrigation-control systems. The conductivity probe has an additional role besides soil analysis. It will serve as a hunidity sensor when held in the air. -
Radar investigation of asteroids
NASA Technical Reports Server (NTRS)
Ostro, S. J.
1986-01-01
The number of radar detected asteroids has climbed from 6 to 40 (27 mainbelt plus 13 near-Earth). The dual-circular-polarization radar sample now comprises more than 1% of the numbered asteroids. Radar results for mainbelt asteroids furnish the first available information on the nature of these objects at macroscopic scales. At least one object (2 Pallas) and probably many others are extraordinarily smooth at centimeter-to-meter scales but are extremely rough at some scale between several meters and many kilometers. Pallas has essentially no small-scale structure within the uppermost several meters of the regolith, but the rms slope of this regolith exceeds 20 deg., much larger than typical lunar values (approx. 7 deg.). The origin of these slopes could be the hypervelocity impact cratering process, whose manifestations are likely to be different on low-gravity, low-radius-of-curvature objects from those on the terrestrial planets. The range of mainbelt asteroid radar albedoes is very broad and implies big variations in regolith porosity or metal concentration, or both. The highest albedo estimate, for 16 Psyche, is consistent with a surface having porosities typical of lunar soil and a composition nearly completely metallic. Therefore, Psyche might be the collisionally stripped core of a differentiated small plant, and might resemble mineralogically the parent bodies of iron meteorites.
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Analysis of the diffuse ionized gas database: DIGEDA
NASA Astrophysics Data System (ADS)
Flores-Fajardo, N.; Morisset, C.; Binette, L.
2009-10-01
Studies of the Diffuse Ionized Gas (DIG) have progressed without providing so far any strict criterion to distinguish DIGs from H II regions. In this work, we compile the emission line measurements of 29 galaxies that are available in the scientific literature, thereby setting up the first DIG database (DIGEDA). Making use of this database, we proceed to analyze the global properties of the DIG using the [NII]λ6583/Hα, [O I]λ6300/Hα, [O III]λ5007/Hβ and [SII]λ6716/Hα lines ratios, including the H α emission measure. This analysis leads us to conclude that the [N II]/Hα ratio provides an objective criterion for distinguishing whether an emission region is a DIG or an H II region, while the EM(Hα) is a useful quantity only when the galaxies are considered individually. Finally, we find that the emission regions of Irr galaxies classified as DIG in the literature appear in fact to be much more similar to H II regions than to the DIGs of spiral galaxies.
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Towards memory-aware services and browsing through lifelogging sensing.
Arcega, Lorena; Font, Jaime; Cetina, Carlos
2013-11-05
Every day we receive lots of information through our senses that is lost forever, because it lacked the strength or the repetition needed to generate a lasting memory. Combining the emerging Internet of Things and lifelogging sensors, we believe it is possible to build up a Digital Memory (Dig-Mem) in order to complement the fallible memory of people. This work shows how to realize the Dig-Mem in terms of interactions, affinities, activities, goals and protocols. We also complement this Dig-Mem with memory-aware services and a Dig-Mem browser. Furthermore, we propose a RFID Tag-Sharing technique to speed up the adoption of Dig-Mem. Experimentation reveals an improvement of the user understanding of Dig-Mem as time passes, compared to natural memories where the level of detail decreases over time.
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Pippi Salle, J L; Sayed, S; Salle, A; Bagli, D; Farhat, W; Koyle, M; Lorenzo, A J
2016-02-01
The optimal treatment of proximal hypospadias remains controversial. Several techniques have been described, but the best approach remains unsettled. To evaluate and compare the complication rates of proximal hypospadias with and without ventral curvature (VC), according to three different surgical techniques: tubularized incised plate (TIP) uretroplasty, dorsal inlay graft TIP (DIG), and staged preputial repair (SR). It was hypothesized that SR performs better than TIP and DIG for proximal hypospadias. Single-center, retrospective chart review of all patients with primary proximal hypospadias reconstructed between 2003 and 2013. The DIG was selectively employed in cases with narrow urethral plate (UP) and deficient spongiosum. Extensive urethral plate (UP) mobilization (UPM), dorsal plication (DP) and/or deep transverse incisions of tunica albuginea (DTITA) were selectively performed when attempting to spare transecting the UP. Division of UP and SR was favored in cases with severe VC (>50°), which was often concurrently managed with DTITA if intrinsic curvature was present. For SR, tubularization of the graft was performed 6 months later. A total of 140 patients were included. Tubularized incised plate (TIP), DIG, and SR techniques were performed in 57, 23, and 60 patients, respectively. The TIP and DIG techniques achieved similar success rates, although DIG was performed in cases of narrow and spongiosum-deficient plates. Reoperation rates with TIP and DIG techniques was 52.6% and 52.1% (NS). Urethro-cutaneous fistulas were seen in 31.5% and 13% of TIP and DIG techniques, respectively. Staged repair accomplished better results than both TIP and DIG techniques, despite being performed in the most unfavorable cases (reoperation rate 28%). After technical modifications, the DIG technique achieved similar outcomes of SR. Proximal hypospadias remains challenging, regardless of the technique utilized for its repair. Urethro-cutaneous fistulas were more commonly seen after long TIP repairs. Approximately half of the patients undergoing long TIP and DIG procedures needed re-intervention, although the percentage decreased significantly with late modifications in the DIG group. Recurrence of VC after TIP and DIG techniques seemed to be a significant and under-reported complication. Staged repairs, despite being performed for the most severe cases, resulted in overall better outcomes. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
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Opportunity Trenches Martian Soil
NASA Technical Reports Server (NTRS)
2004-01-01
The Mars Exploration Rover Opportunity dragged one of its wheels back and forth across the sandy soil at Meridiani Planum to create a hole (bottom left corner) approximately 50 centimeters (19.7 inches) long by 20 centimeters (7.9 inches) wide by 9 centimeters (3.5 inches) deep. The rover's instrument deployment device, or arm, will begin studying the fresh soil at the bottom of this trench later today for clues to its mineral composition and history. Scientists chose this particular site for digging because previous data taken by the rover's miniature thermal emission spectrometer indicated that it contains crystalline hematite, a mineral that sometimes forms in the presence of water. The brightness of the newly-exposed soil is thought to be either intrinsic to the soil itself, or a reflection of the Sun. Opportunity's lander is in the center of the image, and to the left is the rock outcrop lining the inner edge of the small crater that encircles the rover and lander. This mosaic image is made up of data from the rover's navigation and hazard-avoidance cameras.
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Development of a material processing plant for lunar soil
NASA Technical Reports Server (NTRS)
Goettsch, Ulix; Ousterhout, Karl
1992-01-01
Currently there is considerable interest in developing in-situ materials processing plants for both the Moon and Mars. Two of the most important aspects of developing such a materials processing plant is the overall system design and the integration of the different technologies into a reliable, lightweight, and cost-effective unit. The concept of an autonomous materials processing plant that is capable of producing useful substances from lunar regolith was developed. In order for such a materials processing plant to be considered as a viable option, it must be totally self-contained, able to operate autonomously, cost effective, light weight, and fault tolerant. In order to assess the impact of different technologies on the overall systems design and integration, a one-half scale model was constructed that is capable of scooping up (or digging) lunar soil, transferring the soil to a solar furnace, heating the soil in the furnace to liberate the gasses, and transferring the spent soil to a 'tile' processing center. All aspects of the control system are handled by a 386 class PC via D/A, A/D, and DSP (Digital Signal Processor) control cards.
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Farji-Brener, Alejandro G; Elizalde, Luciana; Fernández-Marín, Hermógenes; Amador-Vargas, Sabrina
2016-05-25
Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. © 2016 The Author(s).
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Farji-Brener, Alejandro G.; Elizalde, Luciana; Amador-Vargas, Sabrina
2016-01-01
Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. PMID:27226469
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Extraterrestrial materials processing
NASA Technical Reports Server (NTRS)
Steurer, W. H.
1982-01-01
The first year results of a multi-year study of processing extraterrestrial materials for use in space are summarized. Theoretically, there are potential major advantages to be derived from the use of such materials for future space endeavors. The types of known or postulated starting raw materials are described including silicate-rich mixed oxides on the Moon, some asteroids and Mars; free metals in some asteroids and in small quantities in the lunar soil; and probably volatiles like water and CO2 on Mars and some asteroids. Candidate processes for space materials are likely to be significantly different from their terrestrial counterparts largely because of: absence of atmosphere; lack of of readily available working fluids; low- or micro-gravity; no carbon-based fuels; readily available solar energy; and severe constraints on manned intervention. The extraction of metals and oxygen from lunar material by magma electrolysis or by vapor/ion phase separation appears practical.
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McIntosh, Andrew F; Cox, Philip G
2016-10-01
The African mole-rats (Bathyergidae) are a family of rodents highly adapted for life underground. Previous research has shown that chisel-tooth digging mole-rats (which use their incisors to dig burrows) are clearly distinguishable from scratch diggers (which only use the forelimbs to tunnel) on the basis of morphology of the skull, and that the differences are linked to the production of high bite forces and wide gapes. We hypothesized that the skull of a chisel-tooth digging mole-rat would perform better at wider gapes than that of a scratch digging mole-rat during incisor biting. To test this hypothesis, we created finite-element models of the cranium of the scratch digging Bathyergus suillus and the chisel-tooth digging Fukomys mechowii , and loaded them to simulate incisor bites at different gapes. Muscle loads were scaled such that the ratio of force to surface area was the same in both models. We measured three performance variables: overall stress across the cranium, mechanical efficiency of biting and degree of deformation across the skull. The Fukomys model had a more efficient incisor bite at all gapes, despite having greater average stress across the skull. In addition, the Fukomys model deformed less at wider gapes, whereas the Bathyergus model deformed less at narrower gapes. These properties of the cranial morphology of Fukomys and Bathyergus are congruent with their respective chisel-tooth and scratch digging behaviours and, all other factors being equal, would enable the more efficient production of bite force at wider gapes in Fukomys . However, in vivo measurements of muscle forces and activation patterns are needed to fully understand the complex biomechanics of tooth digging.
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NASA Astrophysics Data System (ADS)
McIntosh, Andrew F.; Cox, Philip G.
2016-10-01
The African mole-rats (Bathyergidae) are a family of rodents highly adapted for life underground. Previous research has shown that chisel-tooth digging mole-rats (which use their incisors to dig burrows) are clearly distinguishable from scratch diggers (which only use the forelimbs to tunnel) on the basis of morphology of the skull, and that the differences are linked to the production of high bite forces and wide gapes. We hypothesized that the skull of a chisel-tooth digging mole-rat would perform better at wider gapes than that of a scratch digging mole-rat during incisor biting. To test this hypothesis, we created finite-element models of the cranium of the scratch digging Bathyergus suillus and the chisel-tooth digging Fukomys mechowii, and loaded them to simulate incisor bites at different gapes. Muscle loads were scaled such that the ratio of force to surface area was the same in both models. We measured three performance variables: overall stress across the cranium, mechanical efficiency of biting and degree of deformation across the skull. The Fukomys model had a more efficient incisor bite at all gapes, despite having greater average stress across the skull. In addition, the Fukomys model deformed less at wider gapes, whereas the Bathyergus model deformed less at narrower gapes. These properties of the cranial morphology of Fukomys and Bathyergus are congruent with their respective chisel-tooth and scratch digging behaviours and, all other factors being equal, would enable the more efficient production of bite force at wider gapes in Fukomys. However, in vivo measurements of muscle forces and activation patterns are needed to fully understand the complex biomechanics of tooth digging.
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NASA Astrophysics Data System (ADS)
Zhang, Kai; Yan, Renbin; Bundy, Kevin; Bershady, Matthew; Haffner, L. Matthew; Walterbos, René; Maiolino, Roberto; Tremonti, Christy; Thomas, Daniel; Drory, Niv; Jones, Amy; Belfiore, Francesco; Sánchez, Sebastian F.; Diamond-Stanic, Aleksandar M.; Bizyaev, Dmitry; Nitschelm, Christian; Andrews, Brett; Brinkmann, Jon; Brownstein, Joel R.; Cheung, Edmond; Li, Cheng; Law, David R.; Roman Lopes, Alexandre; Oravetz, Daniel; Pan, Kaike; Storchi Bergmann, Thaisa; Simmons, Audrey
2017-04-01
Diffuse ionized gas (DIG) is prevalent in star-forming galaxies. Using a sample of 365 nearly face-on star-forming galaxies observed by Mapping Nearby Galaxies at APO, we demonstrate how DIG in star-forming galaxies impacts the measurements of emission-line ratios, hence the interpretation of diagnostic diagrams and gas-phase metallicity measurements. At fixed metallicity, DIG-dominated low ΣHα regions display enhanced [S II]/Hα, [N II]/Hα, [O II]/Hβ and [O I]/Hα. The gradients in these line ratios are determined by metallicity gradients and ΣHα. In line ratio diagnostic diagrams, contamination by DIG moves H II regions towards composite or low-ionization nuclear emission-line region (LI(N)ER)-like regions. A harder ionizing spectrum is needed to explain DIG line ratios. Leaky H II region models can only shift line ratios slightly relative to H II region models, and thus fail to explain the composite/LI(N)ER line ratios displayed by DIG. Our result favours ionization by evolved stars as a major ionization source for DIG with LI(N)ER-like emission. DIG can significantly bias the measurement of gas metallicity and metallicity gradients derived using strong-line methods. Metallicities derived using N2O2 are optimal because they exhibit the smallest bias and error. Using O3N2, R23, N2 = [N II]/Hα and N2S2Hα to derive metallicities introduces bias in the derived metallicity gradients as large as the gradient itself. The strong-line method of Blanc et al. (IZI hereafter) cannot be applied to DIG to get an accurate metallicity because it currently contains only H II region models that fail to describe the DIG.
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Mitigating clogging and arrest in confined self-propelled systems
NASA Astrophysics Data System (ADS)
Savoie, William; Aguilar, Jeffrey; Monaenkova, Daria; Linevich, Vadim; Goldman, Daniel
Ensembles of self-propelling elements, like colloidal surfers, bacterial biofilms, and robot swarms can spontaneously form density heterogeneities. To understand how to prevent potentially catastrophic clogs in task-oriented active matter systems (like soil excavating robots), we present a robophysical study of excavation of granular media in a confined environment. We probe the efficacy of two social strategies observed in our studies of fire ants (S. invicta). The first behavior (denoted as unequal workload) prescribes to each excavator a different probability to enter the digging area. The second behavior (denoted as reversal\\x9D), is characterized by a probability to forfeit excavation when progress is sufficiently obstructed. For equal workload distribution and no reversal behavior, clogs at the digging site prevent excavation for sufficient numbers of robots. Measurements of aggregation relaxation times reveal how the strategies mitigate clogs. The unequal workload behavior reduces the tunnel density, decreasing the probability of clog formation. Reversal behavior, while allowing clogs to form, reduces aggregation relaxation time. We posit that application of social behaviors can be useful for swarm robot systems where global control and organization may not be possible.
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NASA Technical Reports Server (NTRS)
Christoffersen, Roy; Cintala, M. J.; Keller, L. P.; See, T. H.; Horz, F.
2013-01-01
On the Moon, the energetics of smaller impactors and the physical/chemical characteristics of the granular regolith target combine to form a key product of lunar space weathering: chemically reduced shock melts containing optically-active nanophase Fe metal grains (npFe0) [1]. In addition to forming the optically dark glassy matrix phase in lunar agglutinitic soil particles [1], these shock melts are becoming increasingly recognized for their contribution to optically active patina coatings on a wide range of exposed rock and grain surfaces in the lunar regolith [2]. In applying the lessons of lunar space weathering to asteroids, the potential similarities and differences in regolith-hosted shock melts on the Moon compared to those on asteroids has become a topic of increasing interest [3,4]. In a series of impact experiments performed at velocities applicable to the asteroid belt [5], Horz et al. [6] and See and Horz [7] have previously shown that repeated impacts into a gabbroic regolith analog target can produce melt-welded grain aggregates morphologically very similar to lunar agglutinates [6,7]. Although these agglutinate-like particles were extensively analyzed by electron microprobe and scanning electron microscopy (SEM) as part of the original study [7], a microstructural and compositional comparison of these aggregates to lunar soil agglutinates at sub-micron scales has yet to be made. To close this gap, we characterized a representative set of these aggregates using a JEOL 7600 field-emission scanning electron microscope (FE-SEM), and JEOL 2500SE field-emission scanning transmission electron microscope (FE-STEM) both optimized for energy dispersive X-ray spectroscopy (EDX) compositional spectrum imaging at respective analytical spatial resolutions of 0.5 to 1 micron, and 2 to 4 nm.
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Towards Memory-Aware Services and Browsing through Lifelogging Sensing
Arcega, Lorena; Font, Jaime; Cetina, Carlos
2013-01-01
Every day we receive lots of information through our senses that is lost forever, because it lacked the strength or the repetition needed to generate a lasting memory. Combining the emerging Internet of Things and lifelogging sensors, we believe it is possible to build up a Digital Memory (Dig-Mem) in order to complement the fallible memory of people. This work shows how to realize the Dig-Mem in terms of interactions, affinities, activities, goals and protocols. We also complement this Dig-Mem with memory-aware services and a Dig-Mem browser. Furthermore, we propose a RFID Tag-Sharing technique to speed up the adoption of Dig-Mem. Experimentation reveals an improvement of the user understanding of Dig-Mem as time passes, compared to natural memories where the level of detail decreases over time. PMID:24196436
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Digital Modeling and Testing Research on Digging Mechanism of Deep Rootstalk Crops
NASA Astrophysics Data System (ADS)
Yang, Chuanhua; Xu, Ma; Wang, Zhoufei; Yang, Wenwu; Liao, Xinglong
The digital model of the laboratory bench parts of digging deep rootstalk crops were established through adopting the parametric model technology based on feature. The virtual assembly of the laboratory bench of digging deep rootstalk crops was done and the digital model of the laboratory bench parts of digging deep rootstalk crops was gained. The vibrospade, which is the key part of the laboratory bench of digging deep rootstalk crops was simulated and the movement parametric curves of spear on the vibrospade were obtained. The results show that the spear was accorded with design requirements. It is propitious to the deep rootstalk.
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Enhanced yields and soil quality in a wheat-maize rotation using buried straw mulch.
Guo, Zhibin; Liu, Hui; Wan, Shuixia; Hua, Keke; Jiang, Chaoqiang; Wang, Daozhong; He, Chuanlong; Guo, Xisheng
2017-08-01
Straw return may improve soil quality and crop yields. In a 2-year field study, a straw return method (ditch-buried straw return, DB-SR) was used to investigate the soil quality and crop productivity effects on a wheat-corn rotation system. This study consisted of three treatments, each with three replicates: (1) mineral fertilisation alone (CK0); (2) mineral fertilisation + 7500 kg ha -1 wheat straw incorporated at depth of 0-15 cm (NPKWS); and (3) mineral fertilisation + 7500 kg ha -1 wheat straw ditch buried at 15-30 cm (NPKDW). NPKWS and NPKDW enhanced crop yield and improved soil biotical properties compared to mineral fertilisation alone. NPKDW contributed to greater crop yields and soil nutrient availability at 15-30 cm depths, compared to NPKWS treatment. NPKDW enhanced soil microbial activity and bacteria species richness and diversity in the 0-15 cm layer. NPKWS increased soil microbial biomass, bacteria species richness and diversity at 15-30 cm. The comparison of the CK0 and NPKWS treatments indicates that a straw ditch buried by digging to the depth of 15-30 cm can improve crop yields and soil quality in a wheat-maize rotation system. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
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NASA Technical Reports Server (NTRS)
Kojiro, Daniel R.; Mancinelli, Rocco; Martin, Joe; Holland, Paul M.; Stimac, Robert M.; Kaye, William J.
2005-01-01
The Mars Geochemical Instrument, MarGI, was developed to provide a comprehensive analysis of the rocks and surface material on Mars. The instrument combines Differential Thermal Analysis (DTA) with miniature Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) to identify minerals, the presence and state of water, and organic compounds. Miniature pyrolysis ovens are used to both, conduct DTA analysis of soil or crushed rocks samples, and pyrolyze the samples at temperatures up to 1000 degrees C for GC-IMS analysis of the released gases. This combination of analytical processes and techniques, which can characterize the mineralogy of the rocks and soil, and identify and quantify volatiles released during pyrolysis, has applications across a wide range of target sites including comets, planets, asteroids, and moons such as Titan and Europa. The MarGI analytical approach evolved from the Cometary Ice and Dust Experiment (CIDEX) selected to fly on the Comet Rendezvous Asteroid Flyby Mission (CRAF).
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2012-05-22
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center Visitor Complex in Florida, college students prepare their custom lunabot for NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. Photo credit: NASA/Frankie Martin
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2012-05-22
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center Visitor Complex in Florida, college students prepare their custom lunabot for NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. Photo credit: NASA/Frankie Martin
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2012-05-22
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center Visitor Complex in Florida, college students make last minute adjustments to their custom lunabot for NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. Photo credit: NASA/Frankie Martin
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Key performance indicators for electric mining shovels and oil sands diggability
NASA Astrophysics Data System (ADS)
Patnayak, Sibabrata
A shovel performance monitoring study was undertaken in two oil sands mines operated by Syncrude Canada Ltd. using performance data obtained from P&H 4100 TS and BOSS electric mining shovels. One year of shovel performance data along with geological, geotechnical, and climatic data were analyzed. The approach adopted was to use current and voltage data collected from hoist and crowd motors and to calculate the energy and/or power associated with digging. Analysis of performance data along with digital video records of operating shovels indicated that hoist and crowd motor voltages and currents can be used to identify the beginning and the end of individual dig cycles. A dig cycle identification algorithm was developed. Performance indicators such as dig cycle time, hoist motor energy and power, and crowd motor energy and power were determined. The shovel performance indicators provide important insight into how geology, equipment and operators affect the digging efficiency. The hoist motor power is a useful key performance indicator for assessing diggability. Hoist motor energy consumption per tonne of material excavated and the number of dig cycles required for loading a truck can be useful key performance indicators for assessing operator performance and productivity. Analysis of performance data along with operators team schedules showed that the performance of a shovel can be significantly influenced by the operator's digging technique while digging uniform material. Up to 25% variability in hoist motor power consumption and 50% variability in productivity was noted between different operators. Shovel type and dipper teeth configuration can also influence the power draw on electrical motors during digging. There is no common agreement existing on the influence of bitumen content on oil sands diggability. By comparing the hoist motor power consumption, it was found that the rich ore was more difficult to dig than the lean ore. Similarly, estuarine ore was more difficult to dig than marine ore. Winter weather was expected to have a significant influence on oil sands diggability but was found to have only a minor and localized influence that depends upon the ore type, temperature conditions and the duration of bench exposure.
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Dig Hazard Assessment Using a Stereo Pair of Cameras
NASA Technical Reports Server (NTRS)
Rankin, Arturo L.; Trebi-Ollennu, Ashitey
2012-01-01
This software evaluates the terrain within reach of a lander s robotic arm for dig hazards using a stereo pair of cameras that are part of the lander s sensor system. A relative level of risk is calculated for a set of dig sectors. There are two versions of this software; one is designed to run onboard a lander as part of the flight software, and the other runs on a PC under Linux as a ground tool that produces the same results generated on the lander, given stereo images acquired by the lander and downlinked to Earth. Onboard dig hazard assessment is accomplished by executing a workspace panorama command sequence. This sequence acquires a set of stereo pairs of images of the terrain the arm can reach, generates a set of candidate dig sectors, and assesses the dig hazard of each candidate dig sector. The 3D perimeter points of candidate dig sectors are generated using configurable parameters. A 3D reconstruction of the terrain in front of the lander is generated using a set of stereo images acquired from the mast cameras. The 3D reconstruction is used to evaluate the dig goodness of each candidate dig sector based on a set of eight metrics. The eight metrics are: 1. The maximum change in elevation in each sector, 2. The elevation standard deviation in each sector, 3. The forward tilt of each sector with respect to the payload frame, 4. The side tilt of each sector with respect to the payload frame, 5. The maximum size of missing data regions in each sector, 6. The percentage of a sector that has missing data, 7. The roughness of each sector, and 8. Monochrome intensity standard deviation of each sector. Each of the eight metrics forms a goodness image layer where the goodness value of each sector ranges from 0 to 1. Goodness values of 0 and 1 correspond to high and low risk, respectively. For each dig sector, the eight goodness values are merged by selecting the lowest one. Including the merged goodness image layer, there are nine goodness image layers for each stereo pair of mast images.
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NASA Astrophysics Data System (ADS)
Jaumann, Ralf; Bibring, Jean-Piere; Glassmeier, Karl-Heiz; Grott, Mathias; Ho, Tra-Mi; Ulamec, Stefan; Schmitz, Nicole; Auster, Ulrich; Biele, Jens; Kuninaka, Hitoshi; Okada, Tatsuaki; Yoshikawa, Makoto; Watanabe, Sei-ichiro; Fujimoto, Masaki; Spohn, Tilman; Koncz, Aalexander; Hercik, Davis; Michaelis, Harald
2015-04-01
MASCOT, a Mobile Asteroid Surface Scout, will support JAXA's Hayabusa 2 mission to investigate the C-type asteroid 1999 JU3 (1). The German Aer-ospace Center (DLR) develops MASCOT with contributions from CNES (France) (2,3,4). Main objective is to in-situ map the asteroid's geomorphol-ogy, the intimate mixture, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the sur-face in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples. MASCOT comprises a payload of four scientific in-struments: camera, radiometer, magnetometer and hyperspectral microscope. C- and D-type asteroids hold clues to the origin of the solar system, the for-mation of planets, the origins of water and life on Earth, the protection of Earth from impacts, and resources for future human exploration. C- and D-types are dark and difficult to study from Earth, and have only been glimpsed by spacecraft. While results from recent missions (e.g., Hayabusa, NEAR (5, 6, 7)) have dramatically increased our understanding of asteroids, important questions remain open. For example, characterizing the properties of asteroid regolith in-situ would deliver important ground truth for further understanding telescopic and orbital observations and samples of such asteroids. MASCOT will descend and land on the asteroid and will change its own position up to two times by hopping. This enables measurements during descent, at the landing and hopping positions #1-3, and during hopping. Hayabusa 2 together with MASCOT launched December 3rd 2014, will arrive at 1999JU3 in 2018 and return samples back to Earth in 2020. References: (1) Vilas, F., Astronomical J. 1101-1105, 2008; (2) Ulamec, S., et al., Acta Astronautica, Vol. 93, pp. 460-466; (3) Jaumann et al., 45th LPSC, #1812, Houston; (4) Ho et al., 45th LPSC, #2535, Houston; (5) Spe-cial Issue, Science, Vol. 312 no. 5778, 2006; (6) Special Issue Science, Vol. 333 no. 6046, 2011. (7) Bell, L., Mitton, J-., Cambridge Univ. Press, 2002.
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The digastric muscle is less involved in pharyngeal swallowing in rabbits.
Tsujimura, Takanori; Yamada, Aki; Nakamura, Yuki; Fukuhara, Takako; Yamamura, Kensuke; Inoue, Makoto
2012-06-01
The swallowing reflex is centrally programmed by the lower brain stem, the so-called swallowing central pattern generator (CPG), and once the reflex is initiated, many muscles in the oral, pharyngeal, laryngeal, and esophageal regions are systematically activated. The mylohyoid (MH) muscle has been considered to be a "leading muscle" according to previous studies, but the functional role of the digastric (DIG) muscle in the swallowing reflex remains unclear. In the present study, therefore, the activities of single units of MH and DIG neurons were recorded extracellularly, and the functional involvement of these neurons in the swallowing reflex was investigated. The experiments were carried out on eight adult male Japanese white rabbits anesthetized with urethane. To identify DIG and MH neurons, the peripheral nerve (either DIG or MH) was stimulated to evoke action potentials of single motoneurons. Motoneurons were identified as such if they either (1) responded to antidromic nerve stimulation of DIG or MH in an all-or-none manner at threshold intensities and (2) followed stimulation frequencies of up to 0.5 kHz. As a result, all 11 MH neurons recorded were synchronously activated during the swallowing reflex, while there was no activity in any of the 7 DIG neurons recorded during the swallowing reflex. All neurons were anatomically localized ventromedially at the level of the caudal portion of the trigeminal motor nucleus, and there were no differences between the MH and DIG neuron sites. The present results strongly suggest that at least in the rabbit, DIG motoneurons are not tightly controlled by the swallowing CPG and, hence, the DIG muscle is less involved in the swallowing reflex.
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Diffuse ionized gas in galaxies across the Hubble sequence at the CALIFA resolution
NASA Astrophysics Data System (ADS)
Lacerda, E. A. D.; Cid Fernandes, R.; Couto, G. S.; Stasińska, G.; García-Benito, R.; Vale Asari, N.; Pérez, E.; González Delgado, R. M.; Sánchez, S. F.; de Amorim, A. L.
2018-03-01
We use spatially resolved spectroscopy from the Calar Alto Legacy Integral Field Area (CALIFA) survey to study the nature of the line emitting gas in galaxies of different Hubble types, focusing on the separation of star-forming (SF) regions from those better characterized as diffuse ionized gas (DIG). The diagnosis is carried out in terms of the equivalent width of H α (WH α). Three nebular regimes are identified. Regions where WH α < 3 Å define what we call the hDIG, the component of the DIG where photoionization is dominated by hot, low-mass, evolved stars. Regions where WH α > 14 Å trace SF complexes. WH α values in the intermediate 3-14 Å range reflect a mixed regime (mDIG) where more than one process contributes. This three-tier scheme is inspired both by theoretical and empirical considerations. Its application to CALIFA galaxies of different types and inclinations leads to the following results: (i) the hDIG component is prevalent throughout ellipticals and S0's as well as in bulges, and explains the strongly bimodal distribution of WH α both among and within galaxies. (ii) Early-type spirals have some hDIG in their discs, but this component becomes progressively less relevant for later Hubble types. (iii) hDIG emission is also present above and below galactic discs, as seen in several edge-on spirals in our sample. (iv) The SF/mDIG proportion grows steadily from early- to late-type spirals, and from inner to outer radii. (v) Besides circumventing basic inconsistencies in conventional DIG/SF separation criteria based on the H α surface brightness, our WH α-based method produces results in agreement with a classical excitation diagram analysis.
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Diffuse ionized gas in galaxies across the Hubble sequence at the CALIFA resolution
NASA Astrophysics Data System (ADS)
Lacerda, E. A. D.; Cid Fernandes, R.; Couto, G. S.; Stasińska, G.; García-Benito, R.; Vale Asari, N.; Pérez, E.; Gonzalez Delgado, R. M.; Sánchez, S. F.; de Amorim, A. L.
2017-11-01
We use spatially resolved spectroscopy from the CALIFA survey to study the nature of the line emitting gas in galaxies of different Hubble types, focusing on the separation of star-forming (SF) regions from those better characterized as diffuse ionized gas (DIG). The diagnosis is carried out in terms of the equivalent width of Hα (W_{Hα}). Three nebular regimes are identified: Regions where W_{Hα} < 3 Å define what we call the hDIG, the component of the DIG where photoionization is dominated by hot, low mass, evolved stars. Regions where W_{Hα} > 14 Å trace SF complexes. W_{Hα} values in the intermediate 3-14 Å range reflect a mixed regime (mDIG) where more than one process contributes.This three-tier scheme is inspired both by theoretical and empirical considerations. Its application to CALIFA galaxies of different types and inclinations leads to the following results: (i) The hDIG component is prevalent throughout ellipticals and S0's as well as in bulges, and explains the strongly bimodal distribution of W_{{Hα} both among and within galaxies. (ii) Early type spirals have some hDIG in their disks, but this component becomes progressively less relevant for later Hubble types. (iii) hDIG emission is also present above and below galactic disks, as seen in several edge-on spirals in our sample. (iv) The SF/mDIG proportion grows steadily from early to late types spirals, and from inner to outer radii. (v) Besides circumventing basic inconsistencies in conventional DIG/SF separation criteria based on the &Hα surface brightness, our W_{Hα}-based method produces results in agreement with a classical excitation diagram analysis.
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Bramlitt, E T
1988-08-01
Cleanup is the act of making a contaminated site relatively free of Pu so it may be used without radiological safety restrictions. Contaminated ground is the focus of major cleanups. Cleanup traditionally involves determining Pu content of soil, digging up soil in which radioactivity exceeds guidelines, and relocating excised soil to a waste-disposal site. Alternative technologies have been tested at Johnston Atoll (JA), where there is as much as 100,000 m3 of Pu-contaminated soil. A mining pilot plant operated for the first 6 mo of 1986 and made 98% of soil tested "clean", from more than 40 kBq kg-1 (1000 pCi g-1) to less than about 500 Bq kg-1 (15 pCi g-1) by concentrating Pu in 2% of the soil. The pilot plant is now installed at the U.S. Department of Energy Nevada Test Site for evaluating cleanup of other contaminated soils and refining cleanup effectiveness. A full-scale cleanup plant has been programmed for JA in 1988. In this paper, previous cleanups are reviewed, and the mining endeavor at JA is detailed. "True soil cleanup" is contrasted with the classical "soil relocation cleanup." The mining technology used for Pu cleanup has been in use for more than a century. Mining for cleanup, however, is unique. It is envisioned as being prominent for radiological and other cleanups in the future.
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Discontinuous Inter-Granular Separations (DIGS) in the Gas Nitride Layer of ISS Race Rings
NASA Technical Reports Server (NTRS)
Figert, John; Dasgupta, Rajib; Martinez, James
2010-01-01
The starboard solar alpha rotary joint (SARJ) race ring on the International space station (ISS) failed due to severe spalling of the outer diameter, 45 degree (outer canted) nitrided surface. Subsequent analysis at NASA-KSC revealed that almost all of the debris generated due to the failure was nitrided 15-5 stainless steel. Subsequent analysis of the nitride control coupons (NCC) at NASA-JSC revealed the presence of discontinuous inter-granular separations (DIGS) in the gas nitride layer. These DIGS were present in the inter-granular networking located in the top 2 mils of the nitride layer. The manufacturer's specification requires the maximum white structure to be 0.0003 inches and intergranular networking below the allowable white structure depth to be cause for rejection; a requirement that the NCCs did not meet. Subsequent testing and analysis revealed that lower DIGS content significantly lowered the probability of nitride spalling in simulated, dry condition runs. One batch of nitride samples with DIGS content similar to the port SARJ (did not fail on orbit) which exhibited almost no nitride spalling after being run on one test rig. Another batch of nitride samples with DIGS content levels similar to the starboard SARJ exhibited significant nitride spalling on the same test rig with the same load under dry conditions. Although DIGS were not the root cause of starboard race ring failure, testing indicates that increased DIGS reduced the robustness of the gas nitride layer under dry operating conditions.
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ERIC Educational Resources Information Center
Renard, Lisa
2005-01-01
Instant digital communication is going to say and the wise teacher needs to acknowledge and keep pace with the technology that eases and speeds up the way the DIG (digital immediate gratification) generation learns. Some DIG- friendly strategies that teachers can employ to make learning more attractive and meaningful are presented.
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Development of Field Excavator with Embedded Force Measurement
NASA Technical Reports Server (NTRS)
Johnson, K.; Creager, C.; Izadnegahdar, A.; Bauman, S.; Gallo, C.; Abel, P.
2012-01-01
A semi-intelligent excavation mechanism was developed for use with the NASA-built Centaur 2 rover prototype. The excavator features a continuously rotatable large bucket supported between two parallel arms, both of which share a single pivot axis near the excavator base attached to the rover. The excavator is designed to simulate the collection of regolith, such as on the Moon, and to dump the collected soil into a hopper up to one meter tall for processing to extract oxygen. Because the vehicle can be autonomous and the terrain is generally unknown, there is risk of damaging equipment or using excessive power when attempting to extract soil from dense or rocky terrain. To minimize these risks, it is critical for the rover to sense the digging forces and adjust accordingly. It is also important to understand the digging capabilities and limitations of the excavator. This paper discusses the implementation of multiple strain gages as an embedded force measurement system in the excavator's arms. These strain gages can accurately measure and resolve multi-axial forces on the excavator. In order to validate these sensors and characterize the load capabilities, a series of controlled excavation tests were performed at Glenn Research Center with the excavator at various depths and cut angles while supported by a six axis load cell. The results of these tests are both compared to a force estimation model and used for calibration of the embedded strain gages. In addition, excavation forces generated using two different types of bucket edge (straight vs. with teeth) were compared.
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The Morphological Diversity of DIG in Halos of Edge-on Spirals as Revealed by HST/ACS
NASA Astrophysics Data System (ADS)
Rossa, J.; Dahlem, M.; Dettmar, R.-J.; van der Marel, R. P.
2012-09-01
We present new results on extraplanar DIG (eDIG), based on high spatial resolution narrowband imaging observations of four late-type, actively star-forming edge-on spirals, obtained with ACS on-board HST. Our Hα observations reveal a multitude of structures on both small and large scales. Whereas all four galaxies have been studied with ground-based telescopes before, here the small scale structure of the extended emission line gas is presented for the very first time at a spatial resolution of 0.05'', corresponding to 5 pc at the mean distance to our galaxies. The eDIG morphology is very different for all four targets, as a result of their different star formation activity and galaxy mass. There is a very smooth DIG morphology observed in two of the galaxies (NGC 4634 and NGC 5775), whereas the other two (NGC 4700 and NGC 7090) show a much more complex morphology with intricate filaments, and bubbles and supershells. We find that the morphology of the eDIG, in particular the break-up of diffuse emission into filaments in galaxy halos, shows a strong dependence on the level of star formation activity per unit area, and eDIG can be arranged into a morphological sequence.
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Bari, Alfa U; Silva, Helton C; Silva, Mayara T L; Pereira Júnior, Francisco N; Cajazeiras, João B; Sampaio, Alexandre H; Leal, Rodrigo B; Teixeira, Edson H; Rocha, Bruno A M; Nascimento, Kyria S; Nagano, Celso S; Cavada, Benildo S
2013-08-01
A new mannose/glucose-specific lectin, named DigL, was purified from seeds of Dialium guineense by a single step using a Sepharose 4b-Mannose affinity chromatography column. DigL strongly agglutinated rabbit erythrocytes and was inhibited by d-mannose, d-glucose, and derived sugars, especially α-methyl-d-mannopyranoside and N-acetyl-d-glucosamine. DigL has been shown to be a stable protein, maintaining its hemagglutinating activity after incubation at a wide range of temperature and pH values and after incubation with EDTA. DigL is a glycoprotein composite by approximately 2.9% of carbohydrates by weight. By sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis, the purified DigL exhibited an electrophoretic profile consisting of a broad band of 28-30 kDa. Analysis using electrospray ionization mass spectrometry indicated that purified DigL possesses a molecular average mass of 28 452 ± 2 Da and shows the presence of possible glycoforms. In addition, DigL exhibited an intermediary toxic effect on Artemia sp. nauplii, and this effect was both dependent on native structure and mediated by a carbohydrate-binding site. Copyright © 2013 John Wiley & Sons, Ltd.
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Numerical results on the contribution of an earthworm hole to infiltration
NASA Astrophysics Data System (ADS)
Pezzotti, Dario; Barontini, Stefano; Casali, Federico; Comincini, Mattia; Peli, Marco; Ranzi, Roberto; Rizzo, Gabriele; Tomirotti, Massimo; Vitale, Paolo
2017-04-01
On 9 March 2016 the WormEx I experiment was launched at the experimental site of Cividate Camuno (274ma.s.l., Oglio river basin, Central Italian Alps), aiming at contributing to understand how the soil-fauna digging activity affects soil-water flow. Particularly the experiment investigates the effects of earthworms holes on the soil-water constitutive laws, in the uppermost layers of a shallow anthropized soil. In this framework a set of simulations of the water flow in presence of an earthworm hole was preliminarily performed. The FV-FD numerical code AdHydra was used to solve the Richards equation in an axis-symmetric 2D domain around a vertical earthworm hole. The hole was represented both as a void cylinder and as a virtual porous domain with typical constitutive laws of a Δ-soil. The hypothesis of Poiseuille flow and the Jourin-Borelli law applied to determine its conductivity and soil-water retention relationship. Different scenarios of hole depth and infiltration rate were explored. As a result a meaningful change in the downflow condition was observed when burrows intersect a layered soil, both in saturated and partially unsaturated soils, in case a perched water table onsets at the interface between an upper and more conductive soil layer and a lower and less conductive one. These results may contribute to a better understanding of the streamflow generation processes and soil-water movement in shallow layered soils.
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Small solar system bodies as granular systems
NASA Astrophysics Data System (ADS)
Hestroffer, Daniel; Campo Bagatín, Adriano; Losert, Wolfgang; Opsomer, Eric; Sánchez, Paul; Scheeres, Daniel J.; Staron, Lydie; Taberlet, Nicolas; Yano, Hajime; Eggl, Siegfried; Lecomte, Charles-Edouard; Murdoch, Naomi; Radjai, Fahrang; Richardson, Derek C.; Salazar, Marcos; Schwartz, Stephen R.; Tanga, Paolo
2017-06-01
Asteroids and other Small Solar System Bodies (SSSBs) are currently of great scientific and even industrial interest. Asteroids exist as the permanent record of the formation of the Solar System and therefore hold many clues to its understanding as a whole, as well as insights into the formation of planetary bodies. Additionally, SSSBs are being investigated in the context of impact risks for the Earth, space situational awareness and their possible industrial exploitation (asteroid mining). In all these aspects, the knowledge of the geophysical characteristics of SSSB surface and internal structure are of great importance. Given their size, constitution, and the evidence that many SSSBs are not simple monoliths, these bodies should be studied and modelled as self-gravitating granular systems in general, or as granular systems in micro-gravity environments in particular contexts. As such, the study of the geophysical characteristics of SSSBs is a multi-disciplinary effort that lies at the crossroads between Granular Mechanics, Celestial Mechanics, Soil Mechanics, Aerospace Engineering and Computer Sciences.
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Lunar soil and surface processes studies
NASA Technical Reports Server (NTRS)
Glass, B. P.
1975-01-01
Glass particles in lunar soil were characterized and compared to terrestrial analogues. In addition, useful information was obtained concerning the nature of lunar surface processes (e.g. volcanism and impact), maturity of soils and chemistry and heterogeneity of lunar surface material. It is felt, however, that the most important result of the study was that it demonstrated that the investigation of glass particles from the regolith of planetary bodies with little or no atmospheres can be a powerful method for learning about the surface processes and chemistry of planetary surfaces. Thus, the return of samples from other planetary bodies (especially the terrestrial planets and asteroids) using unmanned spacecraft is urged.
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Asteroid Evolution: Role of geotechnical properties
NASA Astrophysics Data System (ADS)
Sanchez Lana, Diego P.
2015-08-01
Over the last decade of Planetary research, the scientific community has made many advances in their understanding of the evolution of asteroids in the Solar System. One particular area of fruitful study started with the bold idea that these small planetary bodies could be gravitational aggregates and initially motivated by several different observations and early simulations.If we start with the idea that asteroids are aggregates of different sized components, and not singular monolithic bodies, it is possible to study them with some of the tools that have been used in the fields of Soil Mechanics and Granular Dynamics. In them, parameters such as porosity, cohesive and tensile strength, angles of friction and repose, particle size distributions, stress states, heterogeneity and yield criteria among others, determine how these granular systems will react when subjected to different, changing, external factors. These external factors are believed to have produced and shaped the asteroids that now exist around us and include solar photon momentum, gravitational tides, micro- and macro-impacts and internal energy dissipation.In this presentation we will review what is known about the surface and interiors of rubble pile asteroids, how different theoretical, experimental and simulation tools have been used to study them, how space mission and ground-based observations have shaped our understanding of their physical reality, and what we expect to learn from future missions. The talk will also touch on some of the latest findings obtained by different groups. In particular we will discuss the rotational evolution of self-gravitating aggregates under the influence of the YORP effect and how their angles of friction, tensile strength, porosity, internal structure and density give rise to different disruption modes and the role they play in the formation of asteroids pairs, tumblers and binary systems.
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Nine Galileo Views in Natural Color of Main-Belt Asteroid Ida
NASA Technical Reports Server (NTRS)
1997-01-01
This set of color images of asteroid 243 Ida was taken by the imaging system on the Galileo spacecraft as it approached and raced past the asteroid on August 28, 1993. These images were taken through the 4100-angstrom (violet), 7560-angstrom (infrared) and 9680- angstrom (infrared) filters and have been processed to show Ida as it would appear to the eye in approximately natural color. The stark shadows portray Ida's irregular shape, which changes its silhouetted outline when seen from different angles. More subtle shadings reveal surface topography (such as craters) and differences in the physical state and composition of the soil ('regolith'). Analysis of the images show that Ida is 58 kilometers long and 23 kilometers wide (36 x 14 miles). Ida is the first asteroid discovered to have a natural satellite, Dactyl (not shown here). Both Ida and Dactyl are heavily cratered by impacts with smaller asteroids and comets, including some of the same populations of small objects that bombard Earth. These data, combined with reflectance spectra from Galileo's near-infrared mapping spectrometer, may allow scientists to determine whether Ida is a relatively unaltered primitive object made of material condensed from the primordial Solar Nebula at the origin of the Solar System or whether it has been altered by strong heating--evidence interpreted so far suggests that Ida is a piece of a larger object that has been severely heated. Whereas heating and melting of large planets is well understood, the cause of heating of small asteroids is more enigmatic--it may have involved exotic processes that occurred only for a short time after the birth of the Sun and its planets.
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Nazarova, Galina G; Proskurniak, Lyudmila P; Yuzhik, Ekaterina I
2016-03-01
We hypothesized that low molecular weight urinary proteins play a role in male-male chemical communication in the water vole, Arvicola ampibius L. We studied the effect of placing soiled litter from strange males into the cage of another sexually mature male on the intensity of its digging and scattering, urination on the litter, and alteration in the levels of low molecular weight proteins (15-25 kDa) excreted in the urine before and after 4 days of exposure as determined by chip electrophoresis. The intensity of digging and scattering was positively correlated with levels of testosterone in serum of males exposed to strange male odors (r = 0.56; P < 0.01), as well as with the concentration of low molecular weight proteins in the donor's urine (r = 0.52, P < 0.05). At the end of the experiment, the level of low molecular weight protein in excreted urine was elevated in the males exposed to the strange male's litter. These results highlight the importance of quantitative inter-individual variation of low molecular weight urinary proteins in the modulation of the physiology and behavior of conspecifics.
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Dielectric properties of Asteroid Vesta's surface as constrained by Dawn VIR observations
NASA Astrophysics Data System (ADS)
Palmer, Elizabeth M.; Heggy, Essam; Capria, Maria T.; Tosi, Federico
2015-12-01
Earth and orbital-based radar observations of asteroids provide a unique opportunity to characterize surface roughness and the dielectric properties of their surfaces, as well as potentially explore some of their shallow subsurface physical properties. If the dielectric and topographic properties of asteroid's surfaces are defined, one can constrain their surface textural characteristics as well as potential subsurface volatile enrichment using the observed radar backscatter. To achieve this objective, we establish the first dielectric model of asteroid Vesta for the case of a dry, volatile-poor regolith-employing an analogy to the dielectric properties of lunar soil, and adjusted for the surface densities and temperatures deduced from Dawn's Visible and InfraRed mapping spectrometer (VIR). Our model suggests that the real part of the dielectric constant at the surface of Vesta is relatively constant, ranging from 2.3 to 2.5 from the night- to day-side of Vesta, while the loss tangent shows slight variation as a function of diurnal temperature, ranging from 6 × 10-3 to 8 × 10-3. We estimate the surface porosity to be ∼55% in the upper meter of the regolith, as derived from VIR observations. This is ∼12% higher than previous estimation of porosity derived from previous Earth-based X- and S-band radar observation. We suggest that the radar backscattering properties of asteroid Vesta will be mainly driven by the changes in surface roughness rather than potential dielectric variations in the upper regolith in the X- and S-band.
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Di Giorgio, C; Boyer, L; De Meo, M; Laurant, C; Elias, R; Ollivier, E
2015-07-01
DIG, a liquid herbal preparation made from a mixture of diluted mother tinctures of Berberis vulgaris, Taraxacum officinale and Arctium lappa, was assessed for its antimutagenic properties against mitomycin C. The micronucleus assay on Chinese hamster ovary (CHO)-K1 cells was used to evaluate the in vitro anticlastogenic activity of DIG compared to those of separately diluted mother tinctures. The micronucleus assay was performed on mouse erythrocytes and the comet assay was performed on mouse liver, kidney, lung, brain and testicles to assess the protective effects of DIG (0.2 and 2 % at libitum) against an intraperitoneal injection of mitomycin C (1 mg Kg(-1)) in mice. DIG exerted a powerful anticlastogenic activity, under both pretreatment and simultaneous treatment conditions as assessed by the micronucleus assay in CHO-K1 cells. Its protective activity was greater than that observed for each mother tincture. DIG reduced micronuclei levels in mouse erythrocytes and suppressed >80 % of DNA strand breaks in the liver, kidney, lung, brain and testicles of mice exposed to mitomycin C.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Stair, D.M. Jr.; Keller, L.J.; Hensel, T.W.
1994-12-31
As residents of contaminated soils and as prey for many species of wildlife, earthworms can serve as integrative biomonitors of soil contamination, which is biologically available to the terrestrial food chain. The assessment of contaminants within earthworm tissue provides a more realistic measurement of the potential biological hazards and ecological risks than physical and chemical measurements of soil. A unique sampling procedure using a mixture of ground mustard powder and water was implemented for cost-effectively collecting earthworms without digging; the procedure minimized occupational exposure to soil contaminants and reduced the quantity of investigation-derived wastes. The study site is located atmore » a closed burial ground for low-level radioactive waste and transuranic waste that lies within the Valley and Ridge Physiographic Province of East Tennessee. Earthworms were maintained in the laboratory for four days to allow passage of the contents of the digestive tract. Earthworm body burdens, castings, and soil were analyzed for gamma-emitting radioisotopes (potassium 40, cobalt 60, cesium 137), strontium 90, trace metals (arsenic, cadmium, chromium, mercury, lead, and selenium), and polychlorinated biphenyls (PCBs). Ecological effects of soil contamination on the earthworms were also assessed through analysis of weight, abundance, and reproductive success.« less
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NASA Astrophysics Data System (ADS)
Jaumann, R.; Bibring, J. P.; Glassmeier, K. H.; Grott, M.; Ho, T. M.; Ulamec, S.; Schmitz, N.; Auster, H. U.; Biele, J.; Kuninaka, H.; Okada, T.; Yoshikawa, M.; Watanabe, S.; Spohn, T.; Koncz, A.; Hercik, D.; Michaelis, H.; Fujimoto, M.
2016-12-01
MASCOT is part of JAXA's Hayabusa 2 asteroid sample return mission that has been launched to asteroid (162173) Ryugu (1,2,3) on Dec 3rd, 2014. It is scheduled to arrive at Ryugu in 2018, and return samples to Earth in 2020. The German Aerospace Center (DLR) developed the lander MASCOT with contributions from CNES (France) (2,3). Ryugu has been classified as a Cg-type (4), believed to be a primitive volatile-rich remnant from the early solar system. Its visible geometric albedo is 0.07±0.01with a diameter of 0.87±0.03 km (5). The thermal inertia indicates thick dust with a cm-sized, gravel-dominated surface layer (5,6). Ryugu shows a retrograde rotation with a period of 7.63±0.01h. Spectral observations indicate iron-bearing phyllosilicates (1) on parts of the surface, suggesting compositional heterogeneity. MASCOT will enable to in-situ map the asteroid's geomorphology, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and its thermal, mechanical, and magnetic properties in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples (2,3). MASCOT comprises a payload of four scientific instruments: camera, radiometer, magnetometer and hyperspectral microscope (2,3). Characterizing the properties of asteroid regolith in-situ will deliver important ground truth for further understanding telescopic and orbital observations as well as samples of asteroids. MASCOT will descend and land on the asteroid and will change its position by hopping (3). (1) Vilas, F., Astro. J. 1101-1105, 2008; (2) Jaumann, R., et al., SSR, DOI 10.1007/s11214-016-0263-2, 2016; (3) Ho, T.-M. et al., SSR, DOI 10.1007/s11214-016-0251-6, 2016; (4) Bus, S.J., Binzel, R.P. Icarus 158, 2002; (5) Hasegawa, T.G., et al., Astron. Soc. Japan 60, 2008; (6) T.G. Müller, T.G., et al., doi 10.1051/0004-6361/201015599, 2011.
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Global Landslides on Rapidly Spinning Spheroids
NASA Astrophysics Data System (ADS)
Scheeres, Daniel J.; Sanchez, P.
2013-10-01
The angle of repose and conditions for global landslides on the surfaces of small, rapidly spinning, spheroidal asteroids are studied. Applying techniques of soil mechanics, we develop a theory for, and examples of, how regolith will fail and flow in this microgravity environment. Our motivation is to develop an understanding of the "top-shaped" class of asteroids based on analytical soil mechanics. Our analysis transforms the entire asteroid surface into a local frame where we can model it as a conventional granular pile with a surface slope, acceleration and height variations as a function of the body's spin rate, shape and density. A general finding is that the lowest point on a rapidly spinning spheroid is at the equator with the effective height of surface material monotonically increasing towards the polar regions, where the height can be larger than the physical radius of the body. We study the failure conditions of both cohesionless and cohesive regolith, and develop specific predictions of the surface profile as a function of the regolith angle of friction and the maximum spin rate experienced by the body. The theory also provides simple guidelines on what the shape may look like, although we do not analyze gravitationally self-consistent evolution of the body shape. The theory is tested with soft-sphere discrete element method granular mechanics simulations to better understand the dynamical aspects of global asteroid landslides. We find significant differences between failure conditions for cohesive and cohesionless regolith. In the case of cohesive regolith, we show that extremely small values of strength (much less than that found in lunar regolith) can stabilize a surface even at very rapid spin rates. Cohesionless surfaces, as expected, fail whenever their surface slopes exceed the angle of friction. Based on our analysis we propose that global landslides and the flow of material towards the equator on spheroidal bodies are precipitated by exogenous effects such as impact induced seismic shaking or torques during planetary flybys.
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The Dig: A Study in Archaeology. Profiles of Promise 6.
ERIC Educational Resources Information Center
Risinger, C. Frederick; And Others
The activity described in this profile is based on the simulation Dig. Although designed primarily for use by social studies classes, Dig was expanded by Glen Ellyn teachers to include language arts, mathematics, and science. The objectives of the one-month unit were to: 1) teach techniques and procedures of archaeologists; 2) introduce students…
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Eldridge, David J; Woodhouse, Jason N; Curlevski, Nathalie J A; Hayward, Matthew; Brown, Mark V; Neilan, Brett A
2015-01-01
Animals that modify their physical environment by foraging in the soil can have dramatic effects on ecosystem functions and processes. We compared bacterial and fungal communities in the foraging pits created by bilbies and burrowing bettongs with undisturbed surface soils dominated by biocrusts. Bacterial communities were characterized by Actinobacteria and Alphaproteobacteria, and fungal communities by Lecanoromycetes and Archaeosporomycetes. The composition of bacterial or fungal communities was not observed to vary between loamy or sandy soils. There were no differences in richness of either bacterial or fungal operational taxonomic units (OTUs) in the soil of young or old foraging pits, or undisturbed soils. Although the bacterial assemblage did not vary among the three microsites, the composition of fungi in undisturbed soils was significantly different from that in old or young foraging pits. Network analysis indicated that a greater number of correlations between bacterial OTUs occurred in undisturbed soils and old pits, whereas a greater number of correlations between fungal OTUs occurred in undisturbed soils. Our study suggests that digging by soil-disturbing animals is likely to create successional shifts in soil microbial and fungal communities, leading to functional shifts associated with the decomposition of organic matter and the fixation of nitrogen. Given the primacy of organic matter decomposition in arid and semi-arid environments, the loss of native soil-foraging animals is likely to impair the ability of these systems to maintain key ecosystem processes such as the mineralization of nitrogen and the breakdown of organic matter, and to recover from disturbance. PMID:25932616
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The Massive Stellar Population in the Diffuse Ionized Gas of M33
NASA Technical Reports Server (NTRS)
Hoopes, Charles G.; Walterbos, Rene A. M.
1995-01-01
We compare Far-UV, H alpha, and optical broadband images of the nearby spiral galaxy M33, to investigate the massive stars associated with the diffuse ionized gas. The H-alpha/FUV ratio is higher in HII regions than in the DIG, possibly indicating that an older population ionizes the DIG. The broad-band colors support this conclusion. The HII region population is consistent with a young burst, while the DIG colors resemble an older population with constant star formation. Our results indicate that there may be enough massive field stars to ionize the DIG, without the need for photon leakage from HII regions.
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Petrology and Composition of HED Polymict Breccias
NASA Technical Reports Server (NTRS)
Mittlefehldt, David W.; Herrin, J. S.; Mertzman, S. A.; Mertzman, K. R.
2010-01-01
The howardite, eucrite and diogenite (HED) clan of meteorites forms the largest suite of achondrites with over 900 named members. The HEDs are igneous rocks and breccias of igneous rocks from a differentiated asteroid [1]. The consensus view is that these rocks hail from the asteroid 4 Vesta, which will be the first target of NASA's Dawn mission. When Dawn arrives at Vesta, she will begin remote imagery and spectroscopy of the surface. The surface she will observe will be dominated by rocks and soils mixed through impact gardening. To help with the interpretation of the remotely sensed data, we have begun a project on the petrologic and compositional study of a suite of HED polymict breccias. Here we report on the preliminary findings of this project.
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Excavation and aggregation as organizing factors in de novo construction by mound-building termites.
Green, Ben; Bardunias, Paul; Turner, J Scott; Nagpal, Radhika; Werfel, Justin
2017-06-14
Termites construct complex mounds that are orders of magnitude larger than any individual and fulfil a variety of functional roles. Yet the processes through which these mounds are built, and by which the insects organize their efforts, remain poorly understood. The traditional understanding focuses on stigmergy, a form of indirect communication in which actions that change the environment provide cues that influence future work. Termite construction has long been thought to be organized via a putative 'cement pheromone': a chemical added to deposited soil that stimulates further deposition in the same area, thus creating a positive feedback loop whereby coherent structures are built up. To investigate the detailed mechanisms and behaviours through which termites self-organize the early stages of mound construction, we tracked the motion and behaviour of major workers from two Macrotermes species in experimental arenas. Rather than a construction process focused on accumulation of depositions, as models based on cement pheromone would suggest, our results indicated that the primary organizing mechanisms were based on excavation. Digging activity was focused on a small number of excavation sites, which in turn provided templates for soil deposition. This behaviour was mediated by a mechanism of aggregation, with termites being more likely to join in the work at an excavation site as the number of termites presently working at that site increased. Statistical analyses showed that this aggregation mechanism was a response to active digging, distinct from and unrelated to putative chemical cues that stimulate deposition. Agent-based simulations quantitatively supported the interpretation that the early stage of de novo construction is primarily organized by excavation and aggregation activity rather than by stigmergic deposition. © 2017 The Author(s).
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Excavation and aggregation as organizing factors in de novo construction by mound-building termites
Bardunias, Paul; Turner, J. Scott; Nagpal, Radhika; Werfel, Justin
2017-01-01
Termites construct complex mounds that are orders of magnitude larger than any individual and fulfil a variety of functional roles. Yet the processes through which these mounds are built, and by which the insects organize their efforts, remain poorly understood. The traditional understanding focuses on stigmergy, a form of indirect communication in which actions that change the environment provide cues that influence future work. Termite construction has long been thought to be organized via a putative ‘cement pheromone’: a chemical added to deposited soil that stimulates further deposition in the same area, thus creating a positive feedback loop whereby coherent structures are built up. To investigate the detailed mechanisms and behaviours through which termites self-organize the early stages of mound construction, we tracked the motion and behaviour of major workers from two Macrotermes species in experimental arenas. Rather than a construction process focused on accumulation of depositions, as models based on cement pheromone would suggest, our results indicated that the primary organizing mechanisms were based on excavation. Digging activity was focused on a small number of excavation sites, which in turn provided templates for soil deposition. This behaviour was mediated by a mechanism of aggregation, with termites being more likely to join in the work at an excavation site as the number of termites presently working at that site increased. Statistical analyses showed that this aggregation mechanism was a response to active digging, distinct from and unrelated to putative chemical cues that stimulate deposition. Agent-based simulations quantitatively supported the interpretation that the early stage of de novo construction is primarily organized by excavation and aggregation activity rather than by stigmergic deposition. PMID:28615497
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ERIC Educational Resources Information Center
Liou, Wei-Kai; Bhagat, Kaushal Kumar; Chang, Chun-Yen
2018-01-01
The aim of this study is to design and implement a digital interactive globe system (DIGS), by integrating low-cost equipment to make DIGS cost-effective. DIGS includes a data processing unit, a wireless control unit, an image-capturing unit, a laser emission unit, and a three-dimensional hemispheric body-imaging screen. A quasi-experimental study…
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Sumbera, Radim; Burda, Hynek; Chitaukali, Wilbert N; Kubová, Jana
2003-08-01
Little is known about seasonal changes in burrowing activity and burrow architecture in subterranean African mole-rats (Bathyergidae, Rodentia). The solitary genus Heliophobius is the least known genus of this family. We examined burrow systems of the silvery mole-rat (Heliophobius argenteocinereus) in Malawi in two periods of the dry season. Burrow pattern was influenced by the time of the year, becoming more reticulated at the peak of the dry season when soil was dry and hard. Overall digging activity did not cease during the dry season; yet burrowing strategy changed and the soil was deposited in tunnels rather than transported to mounds. The length of burrow systems was correlated with the body mass of the respective occupants. In spite of their solitary habits--and contrary to the prediction of the aridity food-distribution hypothesis--silvery mole-rats are able to occupy poor habitats with low food supply.
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2014-05-22
CAPE CANAVERAL, Fla. – Team members check their robot before the start of a mining session in simulated Martian soil in the Caterpillar Mining Arena during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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Root Traits and Phenotyping Strategies for Plant Improvement
Paez-Garcia, Ana; Motes, Christy M.; Scheible, Wolf-Rüdiger; Chen, Rujin; Blancaflor, Elison B.; Monteros, Maria J.
2015-01-01
Roots are crucial for nutrient and water acquisition and can be targeted to enhance plant productivity under a broad range of growing conditions. A current challenge for plant breeding is the limited ability to phenotype and select for desirable root characteristics due to their underground location. Plant breeding efforts aimed at modifying root traits can result in novel, more stress-tolerant crops and increased yield by enhancing the capacity of the plant for soil exploration and, thus, water and nutrient acquisition. Available approaches for root phenotyping in laboratory, greenhouse and field encompass simple agar plates to labor-intensive root digging (i.e., shovelomics) and soil boring methods, the construction of underground root observation stations and sophisticated computer-assisted root imaging. Here, we summarize root architectural traits relevant to crop productivity, survey root phenotyping strategies and describe their advantages, limitations and practical value for crop and forage breeding programs. PMID:27135332
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Root Traits and Phenotyping Strategies for Plant Improvement.
Paez-Garcia, Ana; Motes, Christy M; Scheible, Wolf-Rüdiger; Chen, Rujin; Blancaflor, Elison B; Monteros, Maria J
2015-06-15
Roots are crucial for nutrient and water acquisition and can be targeted to enhance plant productivity under a broad range of growing conditions. A current challenge for plant breeding is the limited ability to phenotype and select for desirable root characteristics due to their underground location. Plant breeding efforts aimed at modifying root traits can result in novel, more stress-tolerant crops and increased yield by enhancing the capacity of the plant for soil exploration and, thus, water and nutrient acquisition. Available approaches for root phenotyping in laboratory, greenhouse and field encompass simple agar plates to labor-intensive root digging (i.e., shovelomics) and soil boring methods, the construction of underground root observation stations and sophisticated computer-assisted root imaging. Here, we summarize root architectural traits relevant to crop productivity, survey root phenotyping strategies and describe their advantages, limitations and practical value for crop and forage breeding programs.
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NASA Technical Reports Server (NTRS)
Mautner, M. N.; Conner, A. J.; Killham, K.; Deamer, D. W.
1997-01-01
Meteoritic materials are investigated as potential early planetary nutrients. Aqueous extracts of the Murchison C2 carbonaceous meteorite are utilized as a sole carbon source by microorganisms, as demonstrated by the genetically modified Pseudomonas fluorescence equipped with the lux gene. Nutrient effects are observed also with the soil microorganisms Nocardia asteroides and Arthrobacter pascens that reach populations up to 5 x 10(7) CFU/ml in meteorite extracts, similar to populations in terrestrial soil extracts. Plant tissue cultures of Asparagus officinalis and Solanum tuberosum (potato) exhibit enhanced pigmentation and some enhanced growth when meteorite extracts are added to partial nutrient media, but inhibited growth when added to full nutrient solution. The meteorite extracts lead to large increases in S, Ca, Mg, and Fe plant tissue contents as shown by X-ray fluorescence, while P, K, and Cl contents show mixed effects. In both microbiological and plant tissue experiments, the nutrient and inhibitory effects appear to be best balanced for growth at about 1:20 (extracted solid : H2O) ratios. The results suggest that solutions in cavities in meteorites can provide efficient concentrated biogenic and early nutrient environments, including high phosphate levels, which may be the limiting nutrient. The results also suggest that carbonaceous asteroid resources can sustain soil microbial activity and provide essential macronutrients for future space-based ecosystems.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Hathcock, Charles Dean
The proposed action being assessed in this document occurs in TA-02 in the bottom of Los Alamos Canyon. The DOE proposes to conduct soil sampling at AOC 02-011 (d), AOC 02- 011(a)(ii), and SWMU 02-005, and excavate soils in AOC 02-011(a)(ii) as part of a corrective actions effort. Additional shallow surface soil samples (soil grab samples) will be collected throughout the TA-02 area, including within the floodplain, to perform ecotoxicology studies (Figures 1 and 2). The excavation boundaries in AOC 02-011(a)(ii) are slightly within the delineated 100-year floodplain. The project will use a variety of techniques for soil sampling andmore » remediation efforts to include hand/digging, standard hand auger/sampling, excavation using machinery such as backhoe and front end loader and small drill rig. Heavy equipment will traverse the floodplain and spoils piles will be staged in the floodplain within developed or previously disturbed areas (e.g., existing paved roads and parking areas). The project will utilize and maintain appropriate best management practices (BMPs) to contain excavated materials, and all pollutants, including oil from machinery/vehicles. The project will stabilize disturbed areas as appropriate at the end of the project.« less
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Education and Policy in Soil Science: The U.S. Experience
NASA Astrophysics Data System (ADS)
Sharpley, Andrew; van Es, Harold; Dick, Richard; Bergfeld, Ellen; Anderson, Karl; Chapman, Susan; Fisk, Susan
2017-04-01
The Soil Science Society of America (SSSA), founded in 1936, fosters the transfer of knowledge and practices to sustain soils globally, and now serves 6,000 members worldwide. It is also home to over 1,000 certified professionals dedicated to advancing the field of soil science. The Society provides information about soils in relation to crop production, environmental quality, ecosystem sustainability, bioremediation, waste management, recycling, and wise land use. We provide high-impact research publications, educational programs, certifications, and science-policy initiatives, which will be described in more detail in this presentation. The need for soil science education to a wider audience and development and promotion of soils-based policy initiatives, has increased in the last decade with recognition of the role soils play in sustaining life, population well-being at the nexus of food, energy, and water security. To address these needs, SSSA has two general public outreach sites online: www.soils.org/discover-soils and https://soilsmatter.wordpress.com/, reaching over a half-million viewers per year, as well as social media platforms. We are dedicated to increasing interest and awareness of soil science among K-12 teachers and their students, and working to integrate more information on soil science into the science curriculum of schools over multiple grade levels. For instance, we have a website dedicated to children (http://www.soils4kids.org/), which describes fun games to play with soil, suggestions for science-fair experiments, and opens their minds to careers in soil science. Another site (http://www.soils4teachers.org/) is dedicated to the needs of school teachers, providing ready resources for the classroom. Society members have even authored books ("Soil! Get the Inside Scoop" for one) to get children aged 9 to 12, excited about the living world of soil. In keeping with the times, a blog called "Soils Matter" is hosted by Society staff and now has over 24,000 views a month. Probably, the most successful recent campaigns have been our "I Heart Soil" brand, which features an array of products with "I Heart Soil" now in 15 languages (including Klingon) and the "I Dig It! Secrets of Soil" exhibit. This exhibit, is a 375-square meter interactive display revealing the complex world of soil and how this underfoot ecosystem supports nearly every form of life on earth. Developed by the Smithsonian's National Museum of Natural History with support from SSSA, "Dig It!" includes interactive displays, hands-on models, videos, and 54 soil monoliths representing soils from each USA state. It was on display at the Smithsonian in Washington, DC for nearly two years, and in 2010, moved to museums in the states of Nebraska, Washington, Minnesota, California and then North Carolina. Another major outreach emphasis of SSSA is the development and promotion of soils-based policy initiatives, with Society policy expert staff located in Washington, DC dedicated to this critical activity. Information on their activities is located on our Society website at https://www.soils.org/science-policy and includes funding concerns, educational briefings, and position statements and reports. For example, our Frontiers in Soil Science activity identified critical needs to augment federal funding and to promote innovation through partnerships between public and private sectors. The Congressional Soils Caucus Alliance communicates with Congressional members and staff to enhance knowledge and understanding of the role that soil and soil science play in addressing the most pressing issues facing the USA and the world. These SSSA activities bore fruit recently, when on December 5, 2016, the White House Office of Science and Technology Policy announced new steps to advance soil health. At the same time, the National Science and Technology Council released a Framework for a Federal Strategic Plan for Soil Science, which aims to identify needs, gaps, and opportunities in soil science; develop opportunities for expanding soil conservation practices and enhancing soil carbon sequestration; and coordinate Federal research priorities for the future. Clearly, the recognition and visibility of the critical role of soils to human and environmental health to diverse population of the USA has never been greater. This provides opportunities and challenges, with the SSSA at the forefront, leading the charge.
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NASA Astrophysics Data System (ADS)
Halboth, Florian; Roces, Flavio
2017-10-01
Air exchange between the large nests of Atta vollenweideri leaf-cutting ants and the environment strongly relies on a passive, wind-induced ventilation mechanism. Air moves through nest tunnels and airflow direction depends on the location of the tunnel openings on the nest mound. We hypothesized that ants might use the direction of airflow along nest tunnels as orientation cue in the context of climate control, as digging workers might prefer to broaden or to close tunnels with inflowing or outflowing air in order to regulate nest ventilation. To investigate anemotactic orientation in Atta vollenweideri, we first tested the ants' ability to perceive air movements by confronting single workers with airflow stimuli in the range 0 to 20 cm/s. Workers responded to airflow velocities ≥ 2 cm/s, and the number of ants reacting to the stimulus increased with increasing airflow speed. Second, we asked whether digging workers use airflow direction as an orientation cue. Workers were exposed to either inflow or outflow of air while digging in the nest and could subsequently choose between two digging sites providing either inflow or outflow of air, respectively. Workers significantly chose the side with the same airflow direction they experienced before. When no airflow was present during initial digging, workers showed no preference for airflow directions. Workers developed preferences for airflow direction only after previous exposure to a given airflow direction. We suggest that experience-modified anemotaxis might help leaf-cutting ants spatially organize their digging activity inside the nest during tasks related to climate control.
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Halboth, Florian; Roces, Flavio
2017-09-19
Air exchange between the large nests of Atta vollenweideri leaf-cutting ants and the environment strongly relies on a passive, wind-induced ventilation mechanism. Air moves through nest tunnels and airflow direction depends on the location of the tunnel openings on the nest mound. We hypothesized that ants might use the direction of airflow along nest tunnels as orientation cue in the context of climate control, as digging workers might prefer to broaden or to close tunnels with inflowing or outflowing air in order to regulate nest ventilation. To investigate anemotactic orientation in Atta vollenweideri, we first tested the ants' ability to perceive air movements by confronting single workers with airflow stimuli in the range 0 to 20 cm/s. Workers responded to airflow velocities ≥ 2 cm/s, and the number of ants reacting to the stimulus increased with increasing airflow speed. Second, we asked whether digging workers use airflow direction as an orientation cue. Workers were exposed to either inflow or outflow of air while digging in the nest and could subsequently choose between two digging sites providing either inflow or outflow of air, respectively. Workers significantly chose the side with the same airflow direction they experienced before. When no airflow was present during initial digging, workers showed no preference for airflow directions. Workers developed preferences for airflow direction only after previous exposure to a given airflow direction. We suggest that experience-modified anemotaxis might help leaf-cutting ants spatially organize their digging activity inside the nest during tasks related to climate control.
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The Effects of Space Weathering at UV Wavelengths: S-Class Asteroids
NASA Technical Reports Server (NTRS)
Hendrix, Amanda R.; Vilas, Faith
2006-01-01
We present evidence that space weathering manifests itself at near-UV wavelengths as a bluing of the spectrum, in contrast with the spectral reddening that has been seen at visible-near-IR wavelengths. Furthermore, the effects of space weathering at UV wavelengths tend to appear with less weathering than do the longer wavelength effects, suggesting that the UV wavelength range is a more sensitive indicator of weathering, and thus age. We report results from analysis of existing near-UV (approx.220-350 nm) measurements of S-type asteroids from the International Ultraviolet Explorer and the Hubble Space Telescope and comparisons with laboratory measurements of meteorites to support this hypothesis. Composite spectra of S asteroids are produced by combining UV spacecraft data with ground-based longer wavelength data. At visible-near-IR wavelengths, S-type asteroids are generally spectrally redder (and darker) than ordinary chondrite meteorites, whereas the opposite is generally true at near-UV wavelengths. Similarly, laboratory measurements of lunar samples show that lunar soils (presumably more weathered) are spectrally redder at longer wavelengths, and spectrally bluer at near-UV wavelengths, than less weathered crushed lunar rocks. The UV spectral bluing may be a result of the addition of nanophase iron to the regolith through the weathering process. The UV bluing is most prominent in the 300-400 nm range, where the strong UV absorption edge is degraded with weathering.
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Near Earth Asteroid redirect missions based on gravity assist maneuver
NASA Astrophysics Data System (ADS)
Ledkov, Anton; Shustov, Boris M.; Eismont, Natan; Boyarsky, Michael; Nazirov, Ravil; Fedyaev, Konstantin
During last years several events attracted world community attention to the hazards of hitting the Earth by sky objects. One of these objects is Apophis asteroid what was expected with nonzero probability to hit the Earth in 2036. Luckily after more precise measurements this event is considered as practically improbable. But the other object has really reached the Earth, entered the atmosphere in the Chelyabinsk area and caused vast damages. After this the hazardous near Earth objects problem received practical confirmation of the necessity to find the methods of its resolution. The methods to prevent collision of the dangerous sky object with the Earth proposed up to now look not practical enough if one mentions such as gravitational tractor or changing the reflectivity of the asteroid surface. Even the method supposing the targeting of the spacecraft to the hazardous object in order to deflect it from initial trajectory by impact does not work because its low mass as compared with the mass of asteroid to be deflected. For example the mass of the Apophis is estimated to be about 40 million tons but the spacecraft which can be launched to intercept the asteroid using contemporary launchers has the mass not more than 5 tons. So the question arises where to find the heavier projectile which is possible to direct to the dangerous object? The answer proposed in our paper is very simple: to search it among small near Earth asteroids. As small ones we suppose those which have the cross section size not more than 12-15 meters and mass not exceeding 1500 -1700 tons. According to contemporary estimates the number of such asteroids is not less than 100000. The other question is how to redirect such asteroid to the dangerous one. In the paper the possibilities are studied to use for that purpose gravity assist maneuvers near Earth. It is shown that even among asteroids included in contemporary catalogue there are the ones which could be directed to the trajectory of the gravity assist maneuver near Earth resulted by following impact with dangerous asteroid. As example of the last one the Apophis was chosen. The required delta-V pulse to be applied to the candidate projectile asteroid to fulfill mentioned change of initial trajectory was confirmed to be comparatively small: not exceeding 10 m/s, and the smallest is about 2 m/s. To fulfilled this maneuver it is necessary to land and to mount on the surface of the asteroid projectile the spacecraft with sufficient amount of propellant onboard. The possible trajectories and demanded maneuvers were explored and it was confirmed that for contemporary space technology it is doable for the small asteroids belonging to the determined by our studies list of candidates supposing some reservations, namely the mass of the found asteroids. This was not considered as decisive obstacle because up to now only about 1% of small enough asteroids are included in catalogue so the list of the appropriate ones is far from to be closed. The studies have been fulfilled aimed to develop the methods to reached required accuracies of asteroid projectile trajectory parameters determination. With existing methods used for the usual spacecraft the limits of achievable accuracies demand the corrections delta-V maneuvers which may exceed the nominal ones. As a result the proposed conception of hazardous asteroids deflection becomes problematic. To overcome this obstacle in the paper new method of trajectory parameters determination is proposed and explored. Practically it is radio interferometer method when one transponder is placed on the asteroid target and two others together with the asteroid projectile form tetrahedron. This system begins to operate in vicinity of target asteroid in autonomous regime and expected to allow reaching the demanded low enough correction maneuver values. Paper gives the estimations of the accuracy of these three bodies relative motion parameters and expected limit values of correction maneuvers needed for hitting the target object. As additional option of planetary defense system construction the idea to redirect small near Earth asteroids onto the orbits resonance with the Earth orbit is explored. It is shown that it is possible to reach it by the use gravity assist maneuvers as it was described above by applying small velocity impulses to the asteroids. At least 11 asteroids were found demanded small enough delta-V for transferring them on such trajectories. After executing these maneuvers one can receive the system of asteroids approaching to the Earth practically each month with a possibility to use them as projectiles or for the purposes of delivering to the Earth their soil samples.
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Percussive Excavation of Lunar Soil
NASA Technical Reports Server (NTRS)
Whittaker, Matthew P.
2008-01-01
It has been suggested using a percussive motion could improve the efficiency of excavation by up to 90%. If this is proven to be true it would be very beneficial to excavation projects on the Moon and Mars. The purpose of this study is to design, build and test a percussive tool which could dig a trench and then compare this data against that of a non-percussive tool of the same shape and size. The results of this test thus far have been inconclusive due to malfunctions in the testbed and percussive bucket; however, experimental results from small scale experiments confirm this higher efficiency and support further testing.
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In Brief: NASA's Phoenix spacecraft lands on Mars
NASA Astrophysics Data System (ADS)
Showstack, Randy; Kumar, Mohi
2008-06-01
After a 9.5-month, 679-million-kilometer flight from Florida, NASA's Phoenix spacecraft made a soft landing in Vastitas Borealis in Mars's northern polar region on 25 May. The lander, whose camera already has returned some spectacular images, is on a 3-month mission to examine the area and dig into the soil of this site-chosen for its likelihood of having frozen water near the surface-and analyze samples. In addition to a robotic arm and robotic arm camera, the lander's instruments include a surface stereo imager; thermal and evolved-gas analyzer; microscopy, electrochemistry, and conductivity analyzer; and a meteorological station that is tracking daily weather and seasonal changes.
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2012-05-23
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center Visitor Complex in Florida, Lunabotics UAM Team students from the Universidad Autonoma Metropolitano in Mexico transport their lunabot to the Lunarena during NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. For more information, visit www.nasa.gov/lunabotics. Photo credit: NASA/Frankie Martin
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2012-05-23
CAPE CANAVERAL, Fla. - At NASA’s Kennedy Space Center Visitor Complex in Florida, college students from the ITT Technical Institute in Henderson, Nev., make last minute adjustments to their custom lunabot, Moon Shredder, for NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. For more information, visit www.nasa.gov/lunabotics. Photo credit: NASA/Frankie Martin
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2017 Robotic Mining Competition
2017-05-24
Energy levels are high in the RoboPit as teams prepare for NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. arel using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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2017 Robotic Mining Competition
2017-05-23
NASA Kennedy Space Center Director Bob Cabana welcomes participants to the agency's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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NASA Technical Reports Server (NTRS)
2004-01-01
This animation shows the Mars Exploration Rover Opportunity digging a hole in the ground at Meridiani Planum, Mars. The rover scraped its front right wheel back and forth across the surface six times by rotating its whole body in place. At the end of each sweep, the wheel changed the direction it was spinning to shove excess dirt out of the way. The resulting trench is about 50 centimeters (19.7 inches) long by 20 centimeters (7.9 inches) wide by 9 centimeters (3.5 inches) deep.
The rover's instrument deployment device, or arm, will begin studying the fresh soil at the bottom of the hole later today for clues to its mineral composition and history. Scientists chose this particular site for trenching because previous data taken by the rover's miniature thermal emission spectrometer indicated that it contains crystalline hematite, a mineral that sometimes forms in the presence of water. The brightness of the newly-exposed soil is thought to be either intrinsic to the soil itself, or a reflection of the Sun.This movie is composed of images taken by the rover's hazard-avoidance camera. -
Beneath Our Feet: Strategies for Locomotion in Granular Media
NASA Astrophysics Data System (ADS)
Hosoi, A. E.; Goldman, Daniel I.
2015-01-01
“If you find yourself in a hole, stop digging.” Although Denis Healey's famous adage ( Metcalfe 2007 ) may offer sound advice for politicians, it is less relevant to worms, clams, and other higher organisms that rely on their digging ability for survival. In this article, we review recent work on the development of simple models that elucidate the fundamental principles underlying digging and burrowing strategies employed by biological systems. Four digging regimes are identified based on dimensionless digger size and the dimensionless inertial number. We select biological organisms to represent three of the four regimes: razor clams, sandfish, and nematodes. Models for all three diggers are derived and discussed, and analogies are drawn to low-Reynolds number swimmers.
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Tang, X; Li, Q; Wu, M; Lin, L; Scholz, M
2016-10-01
Cadmium-enrichment of farmland soil greatly threatens the sustainable use of soil resources and the safe cultivation of grain. This review paper briefly introduces the status of farmland soil as well as grain, which are both often polluted by cadmium (Cd) in China, and illustrates the major sources of Cd contaminants in farmland soil. In order to meet soil environmental quality standards and farmland environmental quality evaluation standards for edible agricultural products, Cd-enriched farmland soil is frequently remediated with the following prevailing techniques: dig and fill, electro-kinetic remediation, chemical elution, stabilisation and solidification, phytoremediation, field management and combined remediation. Most remediation techniques are still at the stage of small-scale trial experiments in China and few techniques are assessed in field trials. After comparing the technical and economical applicability among different Cd-enriched farmland soil remediation techniques, a novel ecological and hydraulic remediation technique has been proposed, which integrated the advantages of chemical elution, solidification and stabilisation, phytoremediation and field management. The ecological and hydraulic remediation concept is based on existing irrigation and drainage facilities, ecological ditches (ponds) and agronomic measures, which mainly detoxify the Cd-enriched soil during the interim period of crop cultivation, and guarantee the grain safety during its growth period. This technique may shift the challenge from soil to water treatment, and thus greatly enhances the remediation efficiency and shortens the remediation duration. Moreover, the proposed ecological and hydraulic remediation method matches well with the practical choice of cultivation while remediation for Cd-enriched soil in China, which has negligible impacts on the normal crop cultivation process, and thus shows great potential for large area applications. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Krenske, Elizabeth H; Davison, Edwin C; Forbes, Ian T; Warner, Jacqueline A; Smith, Adrian L; Holmes, Andrew B; Houk, K N
2012-02-01
Quantum mechanical calculations have been used to study the intramolecular additions of hydroxylamines to alkenes and alkynes ("reverse Cope eliminations"). In intermolecular reverse Cope eliminations, alkynes are more reactive than alkenes. However, competition experiments have shown that tethering the hydroxylamine to the alkene or alkyne can reverse the reactivity order from that normally observed. The exact outcome depends on the length of the tether. In agreement with experiment, a range of density functional theory methods and CBS-QB3 calculations predict that the activation energies for intramolecular reverse Cope eliminations follow the order 6-exo-dig < 5-exo-trig < 5-exo-dig ≈ 7-exo-dig. The order of the barriers for the 5-, 6-, and 7-exo-dig reactions of alkynes arises mainly from differences in tether strain in the transition states (TSs), but is also influenced by the TS interaction between the hydroxylamine and alkyne. Cyclization onto an alkene in the 5-exo-trig fashion incurs slightly less tether strain than a 6-exo-dig alkyne cyclization, but its activation energy is higher because the hydroxylamine fragment must distort more before the TS is reached. If the alkene terminus is substituted with two methyl groups, the barrier becomes so much higher that it is also disfavored compared to the 5- and 7-exo-dig cyclizations. © 2012 American Chemical Society
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Krenske, Elizabeth H.; Davison, Edwin C.; Forbes, Ian T.; Warner, Jacqueline A.; Smith, Adrian L.; Holmes, Andrew B.; Houk, K. N.
2012-01-01
Quantum mechanical calculations have been used to study the intramolecular additions of hydroxylamines to alkenes and alkynes (“reverse Cope eliminations”). In intermolecular reverse Cope eliminations, alkynes are more reactive than alkenes. However, competition experiments have shown that tethering the hydroxylamine to the alkene or alkyne can reverse the reactivity order from that normally observed. The exact outcome depends on the length of the tether. In agreement with experiment, a range of density functional theory methods and CBS-QB3 calculations predict that the activation energies for intramolecular reverse Cope eliminations follow the order 6-exo-dig < 5-exo-trig < 5-exo-dig ≈ 7-exo-dig. The order of the barriers for the 5-, 6-, and 7-exo-dig reactions of alkynes arises mainly from differences in tether strain in the transition states, but is also influenced by the transition-state interaction between the hydroxylamine and alkyne. Cyclization onto an alkene in the 5-exo-trig fashion incurs slightly less tether strain than a 6-exo-dig alkyne cyclization, but its activation energy is higher because the hydroxylamine fragment must distort more before the TS is reached. If the alkene terminus is substituted with two methyl groups, the barrier becomes so much higher that it is also disfavored compared to the 5- and 7-exo-dig cyclizations. PMID:22280245
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Localizing Tortoise Nests by Neural Networks.
Barbuti, Roberto; Chessa, Stefano; Micheli, Alessio; Pucci, Rita
2016-01-01
The goal of this research is to recognize the nest digging activity of tortoises using a device mounted atop the tortoise carapace. The device classifies tortoise movements in order to discriminate between nest digging, and non-digging activity (specifically walking and eating). Accelerometer data was collected from devices attached to the carapace of a number of tortoises during their two-month nesting period. Our system uses an accelerometer and an activity recognition system (ARS) which is modularly structured using an artificial neural network and an output filter. For the purpose of experiment and comparison, and with the aim of minimizing the computational cost, the artificial neural network has been modelled according to three different architectures based on the input delay neural network (IDNN). We show that the ARS can achieve very high accuracy on segments of data sequences, with an extremely small neural network that can be embedded in programmable low power devices. Given that digging is typically a long activity (up to two hours), the application of ARS on data segments can be repeated over time to set up a reliable and efficient system, called Tortoise@, for digging activity recognition.
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Digestible lysine requirements of male broilers from 1 to 42 days of age reassessed.
Cemin, Henrique Scher; Vieira, Sergio Luiz; Stefanello, Catarina; Kipper, Marcos; Kindlein, Liris; Helmbrecht, Ariane
2017-01-01
Three experiments were conducted separately to estimate the digestible Lys (dig. Lys) requirements of Cobb × Cobb 500 male broilers using different statistical models. For each experiment, 1,200 chicks were housed in 48 floor pens in a completely randomized design with 6 treatments and 8 replicates. Broilers were fed diets with increasing dig. Lys levels from 1 to 12 d (Exp. 1), from 12 to 28 d (Exp. 2), and 28 to 42 d (Exp. 3). Increasing dig. Lys levels were equally spaced from 0.97 to 1.37% in Exp. 1, 0.77 to 1.17% in Exp. 2, and 0.68 to 1.07% in Exp. 3. The lowest dig. Lys diets were not supplemented with L-Lysine and all other essential AA met or exceeded recommendations. In Exp. 3, six birds per pen were randomly selected from each replication to evaluate carcass and breast yields. Digestible Lys requirements were estimated by quadratic polynomial (QP), linear broken-line (LBL), quadratic broken-line (QBL), and exponential asymptotic (EA) models. Overall, dig. Lys requirements varied among response variables and statistical models. Increasing dietary dig. Lys had a positive effect on BW, carcass and breast yields. Levels of dig. Lys that optimized performance using QP, LBL, QBL, and EA models were 1.207, 1.036, 1.113, and 1.204% for BWG and 1.190, 1.027, 1.100, and 1.172% for FCR in Exp. 1; 1.019, 0.853, 0.944; 1.025% for BWG and 1.050, 0.879, 1.032, and 1.167% for FCR in Exp. 2; and 0.960, 0.835, 0.933, and 1.077% for BWG, 0.981, 0.857, 0.963, and 1.146% for FCR in Exp. 3. The QP, LBL, QBL, and EA also estimated dig. Lys requirements as 0.941, 0.846, 0.925, and 1.070% for breast meat yield in Exp. 3. In conclusion, Lys requirements vary greatly according to the statistical analysis utilized; therefore, the origin of requirement estimation must be taken into account in order to allow adequate comparisons between references.
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Digestible lysine requirements of male broilers from 1 to 42 days of age reassessed
Cemin, Henrique Scher; Stefanello, Catarina; Kipper, Marcos; Kindlein, Liris; Helmbrecht, Ariane
2017-01-01
Three experiments were conducted separately to estimate the digestible Lys (dig. Lys) requirements of Cobb × Cobb 500 male broilers using different statistical models. For each experiment, 1,200 chicks were housed in 48 floor pens in a completely randomized design with 6 treatments and 8 replicates. Broilers were fed diets with increasing dig. Lys levels from 1 to 12 d (Exp. 1), from 12 to 28 d (Exp. 2), and 28 to 42 d (Exp. 3). Increasing dig. Lys levels were equally spaced from 0.97 to 1.37% in Exp. 1, 0.77 to 1.17% in Exp. 2, and 0.68 to 1.07% in Exp. 3. The lowest dig. Lys diets were not supplemented with L-Lysine and all other essential AA met or exceeded recommendations. In Exp. 3, six birds per pen were randomly selected from each replication to evaluate carcass and breast yields. Digestible Lys requirements were estimated by quadratic polynomial (QP), linear broken-line (LBL), quadratic broken-line (QBL), and exponential asymptotic (EA) models. Overall, dig. Lys requirements varied among response variables and statistical models. Increasing dietary dig. Lys had a positive effect on BW, carcass and breast yields. Levels of dig. Lys that optimized performance using QP, LBL, QBL, and EA models were 1.207, 1.036, 1.113, and 1.204% for BWG and 1.190, 1.027, 1.100, and 1.172% for FCR in Exp. 1; 1.019, 0.853, 0.944; 1.025% for BWG and 1.050, 0.879, 1.032, and 1.167% for FCR in Exp. 2; and 0.960, 0.835, 0.933, and 1.077% for BWG, 0.981, 0.857, 0.963, and 1.146% for FCR in Exp. 3. The QP, LBL, QBL, and EA also estimated dig. Lys requirements as 0.941, 0.846, 0.925, and 1.070% for breast meat yield in Exp. 3. In conclusion, Lys requirements vary greatly according to the statistical analysis utilized; therefore, the origin of requirement estimation must be taken into account in order to allow adequate comparisons between references. PMID:28636626
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Kornegay, J R; Shepard, A P; Hankins, C; Franco, E; Lapointe, N; Richardson, H; Coutleé, F
2001-10-01
We assessed the value of a new digoxigenin (DIG)-labeled generic probe mix in a PCR-enzyme-linked immunosorbent assay format to screen for the presence of human papillomavirus (HPV) DNA amplified from clinical specimens. After screening with this new generic assay is performed, HPV DNA-positive samples can be directly genotyped using a reverse blotting method with product from the same PCR amplification. DNA from 287 genital specimens was amplified via PCR using biotin-labeled consensus primers directed to the L1 gene. HPV amplicons were captured on a streptavidin-coated microwell plate (MWP) and detected with a DIG-labeled HPV generic probe mix consisting of nested L1 fragments from types 11, 16, 18, and 51. Coamplification and detection of human DNA with biotinylated beta-globin primers served as a control for both sample adequacy and PCR amplification. All specimens were genotyped using a reverse line blot assay (13). Results for the generic assay using MWPs and a DIG-labeled HPV generic probe mix (DIG-MWP generic probe assay) were compared with results from a previous analysis using dot blots with a radiolabeled nested generic probe mix and type-specific probes for genotyping. The DIG-MWP generic probe assay resulted in high intralaboratory concordance in genotyping results (88% versus 73% agreement using traditional methods). There were 207 HPV-positive results using the DIG-MWP method and 196 positives using the radiolabeled generic probe technique, suggesting slightly improved sensitivity. Only one sample failed to test positive with the DIG-MWP generic probe assay in spite of a positive genotyping result. Concordance between the two laboratories was nearly 87%. Approximately 6% of samples that were positive or borderline when tested with the DIG-MWP generic probe assay were not detected with the HPV type-specific panel, perhaps representing very rare or novel HPV types. This new method is easier to perform than traditional generic probe techniques and uses more objective interpretation criteria, making it useful in studies of HPV natural history.
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Expanding the horizons of soil science to the public
NASA Astrophysics Data System (ADS)
Lindbo, David L.; Hopmans, Jan; Olson, Carolyn; Fisk, Susan; Chapman, Susan
2015-04-01
Soils are critical to all life on the planet yet most individuals treat soil like dirt. As soil scientist we have long recognized this and have struggled to find ways to communicate the importance of soils to the public. The goal is not purely altruistic as we recognize that society funds or research and provides the workforce in soils that we need to continue to gain knowledge and expertise in soil science. In 2006 the Soil Science Society of America took a bold move and created its K12 Committee in part to compliment the Dig It! The Secrets of Soil exhibit that opened in July 2008 at the Smithsonian's Institution's Nation Museum of Natural History (of which SSS was a founding sponsor). The committee's work began quickly with a website designed to provide resources for K12 teachers (primary and school teachers). The first accomplishments included reviewing and posting links to web based information already available to teachers. These links were sorted by subject and grade level to make it easier for teachers to navigate the web and find what they needed quickly. Several presentations and lessons designed for K12 teachers were also posted at this time. Concurrent with this effort a subcommittee review and organized the national teaching standards to show where soils could fit into the overall K12 curriculum. As the website was being developed another subcommittee developed a soils book (Soil! Get the Inside Scoop, 2008) to further compliment the Dig It! exhibit. This was a new endeavor for SSSA having never worked with the non-academic audience in developing a book. Peer-reviews of this book included not only scientist but also students in order to make sure the book was attractive to them. Once the book was published and the website developed it became clear more outreach was needed. SSSA K12 Committee has attended both the National Science Teachers Association (since 2008) the USA Science and Engineering Festival (since 2010) with exhibits and workshops. It has cooperated and contributed to the American Geologic Institutes' Earth Science Week materials with brochures and lesson plans and with National Association of Conservation Districts by providing peer-review and distribution of materials. The most recent developments from the committee include a web redesign that is more student and teacher friendly, the development of a peer-review system to publish K12 Lesson Plans, and finally the publication of a new soils book (Know Soils, Know Life, 2012) for the 8-12th grade audience. It is hoped that Know Soils, Know Life will be used by the Cannon Envirothon and environmental science students and teachers. Future activities planned include a state soils book, teacher's guide for Know Soils, Know Life and development of a searchable digital photo/video library. Overall this committee has been exceedingly productive in its brief 8 year history. Most recently and in part based on the success of the K12 Committee's success, SSSA created an Identity Committee with the goal of not only reaching our members and other related scientist but also to better engage the public and the media. The efforts of this committee have been to redesign our web site to make it more accessible to the general public. The opening page has interest of a general nature and links that some who knows nothing (or very little) about soils can navigate to find out more. Prominent on this home page are links to soil questions posed by the public and answered by soil scientists. There is also a soil related blog as well as a resource for soil photos. In order to encourage secondary school students to consider a career involving soils there are profiles of individuals who are researchers, consultants, teachers and artists as well as soil scientists. The hope is that all this information will inspire a new generation of soil scientist as well as help the general public understand that soil is not just dirt.
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The Twenty-Fifth Lunar and Planetary Science Conference. Part 1: A-G
NASA Technical Reports Server (NTRS)
1994-01-01
Papers from the conference are presented, and the topics covered include the following: planetary geology, meteorites, planetary composition, meteoritic composition, planetary craters, lunar craters, meteorite craters, petrology, petrography, volcanology, planetary crusts, geochronology, geomorphism, mineralogy, lithology, planetary atmospheres, impact melts, volcanoes, planetary evolution, tectonics, planetary mapping, asteroids, comets, lunar soil, lunar rocks, lunar geology, metamorphism, chemical composition, meteorite craters, and planetary mantles.
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Reversed palatal perforation by upper incisors in ageing blind mole-rats (Spalax ehrenbergi)
ZURI, I.; TERKEL, J.
2001-01-01
Blind mole-rats (Spalax ehrenbergi) are fossorial solitary rodents that present striking morphological, physiological and behavioural adaptations to the subterranean environment in which they live. Previous studies have shown that mole-rats are specialised in tooth-digging. The rapid eruption-rate of their incisors has evolved to compensate for their excessive wear by excavation. Males use their incisors more than females for digging and fighting, and their rate of incisor eruption is significantly more rapid than in females. Since mole-rats use their incisors for digging throughout the year, we suggest that continuous mechanical pressure on their oral tissues concentrated at the apical sites of the upper incisors leads to cell and tissue fatigue. We provide evidence for 5 stages of palatal perforation by the upper incisors at their apical sites, with maximum perforation characterising aged males. Interspecies comparisons with 7 other fossorial and semi-fossorial rodent species, and with beavers, which expose their incisors to enormous mechanical pressure, revealed that this palatal perforation is unique to the male mole-rat. We suggest that while the fast eruption rate of incisors in the mole-rat compensates for the rapid wear resulting from digging, evolutionary adaptation to continuous tooth-digging is still ongoing, since the physical pressure of digging at the apical sites of the upper incisors leads to tissue destruction, breakage of the palatal bone and possibly to death, as a result of maxillary inflammation. PMID:11760890
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2012-05-23
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center Visitor Complex in Florida, college students from The University of Akron in Ohio prepare their Lunabot, S.T.E.V.E., for the Lunarena during NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. For more information, visit www.nasa.gov/lunabotics. Photo credit: NASA/Frankie Martin
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1997-08-08
This is an image of the rover Sojourner at the feature called Mermaid Dune at the MPF landing site. Mermaid is thought to be a low, transverse dune ridge, with its long (approximately 2 meters) axis transverse to the wind, which is thought to come from the lower left of the image and blow toward the upper right. The rover is facing to the lower left, the "upwind" direction. The rover's middle wheels are at the crestline of the small dune, and the rear wheels are on the lee side of the feature. A soil mechanics experiment was performed to dig into the dune and examine the sediments exposed. http://photojournal.jpl.nasa.gov/catalog/PIA00794
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2017 Robotic Mining Competition
2017-05-23
College team members watch a live display of their mining robots during test runs in the mining arena at NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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2017 Robotic Mining Competition
2017-05-24
Team members from the New York University Tandon School of Engineering transport their robot to the mining arena during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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2017 Robotic Mining Competition
2017-05-23
College team members prepare to enter the robotic mining arena for a test run during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition - Activities
2018-05-16
Team members cheer during their robot miner's turn in the mining arena on the third day of NASA's 9th Robotic Mining Competition, May 16, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
A volunteer talks with a mining judge near the mining arena on the third day of NASA's 9th Robotic Mining Competition, May 16, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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2017 Robotic Mining Competition
2017-05-23
Team members from Purdue University prepare their uniquely-designed robot miner in the RoboPit at NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Surface penetrators for planetary exploration: Science rationale and development program
NASA Technical Reports Server (NTRS)
Murphy, J. P.; Reynolds, R. T.; Blanchard, M. B.; Clanton, U. S.
1981-01-01
Work on penetrators for planetary exploration is summarized. In particular, potential missions, including those to Mars, Mercury, the Galilean satellites, comets, and asteroids are described. A baseline penetrator design for the Mars mission is included, as well as potential instruments and their status in development. Penetration tests in soft soil and basalt to study material eroded from the penetrator; changes in the structure, composition, and physical properties of the impacted soil; seismic coupling; and penetrator deflection caused by impacting rocks, are described. Results of subsystem studies and tests are given for design of entry decelerators, high-g components, thermal control, data acquisition, and umbilical cable deployment.
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The photoionization of the diffuse galactic gas
NASA Technical Reports Server (NTRS)
Mathis, J. S.
1986-01-01
In a study of the diffuse ionized gas (DIG) component of the interstellar medium, it is attempted to see if the general properties of dilute gas ionized by O stars are similar to observations and to what extent the observations of the DIG can be used to determine the nature of the ionizing radiation field at great distances above the plane of the Galaxy. It has been suggested by Reynolds (1985) that either shocks or photoionization might be responsible for the DIG. The photoionization model seems required by the observations.
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NASA Technical Reports Server (NTRS)
2007-01-01
A vital instrument on NASA's Phoenix Mars Lander is the robotic arm, which will dig into the icy soil and bring samples back to the science deck of the spacecraft for analysis. In September 2006 at a Lockheed Martin Space Systems clean room facility near Denver, spacecraft technician Billy Jones inspects the arm during the assembly phase of the mission. Using the robotic arm -- built by the Jet Propulsion Laboratory, Pasadena -- the Phoenix mission will study the history of water and search for complex organic molecules in the ice-rich soil. The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena. -
2014-05-22
CAPE CANAVERAL, Fla. – A mining team exits the Caterpillar Mining Area with its robot as another team prepares to lower its robot into the simulated Martian soil during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-21
CAPE CANAVERAL, Fla. – A robot dumps its load of simulated Martian soil in a collector in the Caterpillar Mining Arena during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. A competition judge monitors the progress. More than 35 teams from colleges and universities around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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Comparison of ISRU Excavation System Model Blade Force Methodology and Experimental Results
NASA Technical Reports Server (NTRS)
Gallo, Christopher A.; Wilkinson, R. Allen; Mueller, Robert P.; Schuler, Jason M.; Nick, Andrew J.
2010-01-01
An Excavation System Model has been written to simulate the collection and transportation of regolith on the Moon. The calculations in this model include an estimation of the forces on the digging tool as a result of excavation into the regolith. Verification testing has been performed and the forces recorded from this testing were compared to the calculated theoretical data. A prototype lunar vehicle built at the NASA Johnson Space Center (JSC) was tested with a bulldozer type blade developed at the NASA Kennedy Space Center (KSC) attached to the front. This is the initial correlation of actual field test data to the blade forces calculated by the Excavation System Model and the test data followed similar trends with the predicted values. This testing occurred in soils developed at the NASA Glenn Research Center (GRC) which are a mixture of different types of sands and whose soil properties have been well characterized. Three separate analytical models are compared to the test data.
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NASA Technical Reports Server (NTRS)
Gallo, Christopher A.; Agui, Juan H.; Creager, Colin M.; Oravec, Heather A.
2012-01-01
An Excavation System Model has been written to simulate the collection and transportation of regolith on the moon. The calculations in this model include an estimation of the forces on the digging tool as a result of excavation into the regolith. Verification testing has been performed and the forces recorded from this testing were compared to the calculated theoretical data. The Northern Centre for Advanced Technology Inc. rovers were tested at the NASA Glenn Research Center Simulated Lunar Operations facility. This testing was in support of the In-Situ Resource Utilization program Innovative Partnership Program. Testing occurred in soils developed at the Glenn Research Center which are a mixture of different types of sands and whose soil properties have been well characterized. This testing is part of an ongoing correlation of actual field test data to the blade forces calculated by the Excavation System Model. The results from this series of tests compared reasonably with the predicted values from the code.
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8. Photocopy of engineering drawing. AETR DIGS FACILITY THEODOLITE AND ...
8. Photocopy of engineering drawing. AETR DIGS FACILITY THEODOLITE AND PRISM SHELTER: SECTIONS AND DETAILS, 1971. - Cape Canaveral Air Station, Launch Complex 17, Facility 28413, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL
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Digging Up Local History | Poster
By Carolynne Keenan, Contributing Writer In the beginning weeks of summer, Recreation and Welfare (R&W) Club Frederick members experienced a once-in-a-lifetime activity: an archaeological dig in Walkersville, alongside Charlie Hall, Ph.D., Maryland state terrestrial archaeologist.
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Digging a Vegetarian Diet: Plant-Based Eating Can Reap Rewards
... 2012 Print this issue Digging a Vegetarian Diet Plant-Based Eating Can Reap Rewards Send us your ... other ailments. The fact is, eating a more plant-based diet can boost your health, whether you’ ...
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Density Bounded H II Regions: Ionization of the Diffuse Interstellar and Intergalactic Media
NASA Astrophysics Data System (ADS)
Zurita, A.; Rozas, M.; Beckman, J. E.
2000-05-01
We present a study of the diffuse ionized gas (DIG) for a sample of nearby spiral galaxies using Hα images, after constructing their H II region catalogues. The integrated Hα emission of the DIG accounts for between 25% to 60% of the total Hα of the galaxy and a high ionizing photon flux is necessary to keep this gas ionized. We suggest that Lyman photons leaking from the most luminous H II regions are the prime source of the ionization of the DIG; they are more than enough to ionize the measured DIG in the model in which H II regions with luminosity in Hα greater than LStr=1038.6 erg sme are density bounded. We go on to show that this model can quantify the ionization observed in the skins of the high velocity clouds well above the plane of our Galaxy and predicts the ionization of the intergalactic medium.
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Numerical Simulations of Granular Physics in the Solar System
NASA Astrophysics Data System (ADS)
Ballouz, Ronald
2017-08-01
Granular physics is a sub-discipline of physics that attempts to combine principles that have been developed for both solid-state physics and engineering (such as soil mechanics) with fluid dynamics in order to formulate a coherent theory for the description of granular materials, which are found in both terrestrial (e.g., earthquakes, landslides, and pharmaceuticals) and extra-terrestrial settings (e.g., asteroids surfaces, asteroid interiors, and planetary ring systems). In the case of our solar system, the growth of this sub-discipline has been key in helping to interpret the formation, structure, and evolution of both asteroids and planetary rings. It is difficult to develop a deterministic theory for granular materials due to the fact that granular systems are composed of a large number of elements that interact through a non-linear combination of various forces (mechanical, gravitational, and electrostatic, for example) leading to a high degree of stochasticity. Hence, we study these environments using an N-body code, pkdgrav, that is able to simulate the gravitational, collisional, and cohesive interactions of grains. Using pkdgrav, I have studied the size segregation on asteroid surfaces due to seismic shaking (the Brazil-nut effect), the interaction of the OSIRIS-REx asteroid sample-return mission sampling head, TAGSAM, with the surface of the asteroid Bennu, the collisional disruptions of rubble-pile asteroids, and the formation of structure in Saturn's rings. In all of these scenarios, I have found that the evolution of a granular system depends sensitively on the intrinsic properties of the individual grains (size, shape, sand surface roughness). For example, through our simulations, we have been able to determine relationships between regolith properties and the amount of surface penetration a spacecraft achieves upon landing. Furthermore, we have demonstrated that this relationship also depends on the strength of the local gravity. By comparing our numerical results to laboratory experiments and observations by spacecraft we can begin to understand which microscopic properties (i.e., grain properties) control the macroscopic properties of the system. For example, we can compare the mechanical response of a spacecraft to landing or Cassini observations of Saturn's ring to understand how the penetration depth of a spacecraft or the complex optical depth structure of a ring system depends on the size and surface properties of the grains in those systems.
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Advanced Curation of Current and Future Extraterrestrial Samples
NASA Technical Reports Server (NTRS)
Allen, Carlton C.
2013-01-01
Curation of extraterrestrial samples is the critical interface between sample return missions and the international research community. Curation includes documentation, preservation, preparation, and distribution of samples. The current collections of extraterrestrial samples include: Lunar rocks / soils collected by the Apollo astronauts Meteorites, including samples of asteroids, the Moon, and Mars "Cosmic dust" (asteroid and comet particles) collected by high-altitude aircraft Solar wind atoms collected by the Genesis spacecraft Comet particles collected by the Stardust spacecraft Interstellar dust collected by the Stardust spacecraft Asteroid particles collected by the Hayabusa spacecraft These samples were formed in environments strikingly different from that on Earth. Terrestrial contamination can destroy much of the scientific significance of many extraterrestrial materials. In order to preserve the research value of these precious samples, contamination must be minimized, understood, and documented. In addition the samples must be preserved - as far as possible - from physical and chemical alteration. In 2011 NASA selected the OSIRIS-REx mission, designed to return samples from the primitive asteroid 1999 RQ36 (Bennu). JAXA will sample C-class asteroid 1999 JU3 with the Hayabusa-2 mission. ESA is considering the near-Earth asteroid sample return mission Marco Polo-R. The Decadal Survey listed the first lander in a Mars sample return campaign as its highest priority flagship-class mission, with sample return from the South Pole-Aitken basin and the surface of a comet among additional top priorities. The latest NASA budget proposal includes a mission to capture a 5-10 m asteroid and return it to the vicinity of the Moon as a target for future sampling. Samples, tools, containers, and contamination witness materials from any of these missions carry unique requirements for acquisition and curation. Some of these requirements represent significant advances over methods currently used. New analytical and screening techniques will increase the value of current sample collections. Improved web-based tools will make information on all samples more accessible to researchers and the public. Advanced curation of current and future extraterrestrial samples includes: Contamination Control - inorganic / organic Temperature of preservation - subfreezing / cryogenic Non-destructive preliminary examination - X-ray tomography / XRF mapping / Raman mapping Microscopic samples - handling / sectioning / transport Special samples - unopened lunar cores Informatics - online catalogs / community-based characterization.
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Mercury Distribution in the Processing of Jatiroto Gold Mine Wonogiri Central Java Indonesia
NASA Astrophysics Data System (ADS)
Fitri Yudiantoro, Dwi; Nurcholis, Muhammad; Sri Sayudi, Dewi; Abdurrachman, Mirzam; Paramita Haty, Intan; Pambudi, Wiryan; Subroborini, Arum
2017-06-01
The research area is one of the Wonogiri gold producer. In this region there are nearly 30 gold processing locations. This area has a steep morphology which is part of Mt. Mas. The work of the gold processing is a part time job besides for the local farmer population. To get the gold bearing rocks, are by digging holes manually around Mt. Mas, while gold processing is carried out in their homes. As a result of these activities, then identified the distribution of mercury in the surrounding settlements. Analytical methods used in this study is the measurement mercury content using Hg meter on altered rocks, soil and using XRF (X-Ray Fluorescence) for plant samples. This results of research shows that there are conducted on mercury contents in the altered rocks, soil and plants showed significant mercury contents in altered rocks, soil and plants. This proves that mercury has polluted the environment surrounding residents, both of people living in the hill down on the lower plain areas. The results of this study are expected to be used as reference to help overcome the pollution of the area.
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Geophagia in Transkei region of South Africa: case reports.
Meel, B L
2012-12-01
Soil has been eaten by humans under various names all over the world. It was used as a spread on the bread instead of butter in Austria known as 'mountain tallow' and in German known as 'stone butter'. Earth is tasty in various countries, termed as 'American earth', 'Earth of Samos' and 'Nishapoor earth', continues to make geophagia habit. To highlight the problem of geophagia in the Transkei region of South Africa. First, one is (XM) of a 35 years woman who divulges her history of geophagia at Sinawe Center. She consumed fresh earthworm dig-out soil after smelling it. This has happened in her first pregnancy in her first trimester. The second, one is an adult women 55-years; she had consumed red bricks for last 15 years. It is not related with her pregnancy. She keeps bricks close her bed and eats when she feels to eat. She used to complain abdominal pain and off and on loose motions. She had bladder stones, which passed through urethra. The history of geophagia, mechanism of craving for soil, and associated cultural belief has discussed in this case report. There is geophagia in the Xhosa community is prevalent and socially accepted.
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The impact of digging on craniodental morphology and integration.
McIntosh, A F; Cox, P G
2016-12-01
The relationship between the form and function of the skull has been the subject of a great deal of research, much of which has concentrated on the impact of feeding on skull shape. However, there are a number of other behaviours that can influence craniodental morphology. Previous work has shown that subterranean rodents that use their incisors to dig (chisel-tooth digging) have a constrained cranial shape, which is probably driven by a necessity to create high bite forces at wide gapes. Chisel-tooth-digging rodents also have an upper incisor root that is displaced further back into the cranium compared with other rodents. This study quantified cranial shape and upper incisors of a phylogenetically diverse sample of rodents to determine if chisel-tooth-digging rodents differ in craniodental morphology. The study showed that the crania of chisel-tooth-digging rodents shared a similar place in morphospace, but a strong phylogenetic signal within the sample meant that this grouping was nonsignificant. It was also found that the curvature of the upper incisor in chisel-tooth diggers was significantly larger than in other rodents. Interestingly, most subterranean rodents in the sample (both chisel-tooth and scratch diggers) had upper incisors that were better able to resist bending than those of terrestrial rodents, presumably due to their similar diets of tough plant materials. Finally, the incisor variables and cranial shape were not found to covary consistently in this sample, highlighting the complex relationship between a species' evolutionary history and functional morphology. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.
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Clearing Unexploded Ordnance: Bayesian Methodology for Assessing Success
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anderson, K K.
2005-10-30
The Department of Defense has many Formerly Used Defense Sites (FUDS) that are slated for transfer for public use. Some sites have unexploded ordnance (UXO) that must be cleared prior to any land transfers. Sites are characterized using geophysical sensing devices and locations are identified where possible UXO may be located. In practice, based on the analysis of the geophysical surveys, a dig list of N suspect locations is created for a site that is possibly contaminated with UXO. The suspect locations on the dig list are often assigned into K bins ranging from ``most likely to contain UXO" tomore » ``least likely to be UXO" based on signal discrimination techniques and expert judgment. Usually all dig list locations are sampled to determine if UXO is present before the site is determined to be free of UXO. While this method is 100% certain to insure no UXO remains in the locations identified by the signal discrimination and expert judgment, it is very costly. This paper proposes a statistical Bayesian methodology that may result in digging less than 100% of the suspect locations to reach a pre-defined tolerable risk, where risk is defined in terms of a low probability that any UXO remains in the unsampled dig list locations. Two important features of a Bayesian approach are that it can account for uncertainties in model parameters and that it can handle data that becomes available in stages. The results from each stage of data can be used to direct the subsequent digs.« less
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Twenty-Fourth Lunar and Planetary Science Conference. Part 2: G-M
NASA Technical Reports Server (NTRS)
1993-01-01
The topics covered include the following: meteorites, meteoritic composition, geochemistry, planetary geology, planetary composition, planetary craters, the Moon, Mars, Venus, asteroids, planetary atmospheres, meteorite craters, space exploration, lunar geology, planetary surfaces, lunar surface, lunar rocks, lunar soil, planetary atmospheres, lunar atmosphere, lunar exploration, space missions, geomorphology, lithology, petrology, petrography, planetary evolution, Earth surface, planetary surfaces, volcanology, volcanos, lava, magma, mineralogy, minerals, ejecta, impact damage, meteoritic damage, tectonics, etc.
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Twenty-Fourth Lunar and Planetary Science Conference. Part 3: N-Z
NASA Technical Reports Server (NTRS)
1993-01-01
Papers from the conference are presented, and the topics covered include the following: planetary geology, meteorites, planetary composition, meteoritic composition, planetary craters, lunar craters, meteorite craters, petrology, petrography, volcanology, planetary crusts, geochronology, geomorphism, mineralogy, lithology, planetary atmospheres, impact melts, K-T Boundary Layer, volcanoes, planetary evolution, tectonics, planetary mapping, asteroids, comets, lunar soil, lunar rocks, lunar geology, metamorphism, chemical composition, meteorite craters, planetary mantles, and space exploration.
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Lunar and Planetary Science XXXVI, Part 17
NASA Technical Reports Server (NTRS)
2005-01-01
The following topics were discussed: A Model for the Formation of Paterae on Io; LIBS-based Detection of As, Br, C, Cl, P, and S in the VUV Spectral Region in a Mars Atmosphere; Mass Independent Sulfur in Achondrites: Possible Evidence of Photochemistry in the Solar Nebula; Grain Size-dependent Viscosity and Oceans in Icy Satellites; Claritas Paleolake Studied from the MEX HRSC Data; Mars Express HRSC Colors of White Rock, Arabia, Mars; Lava and Flows of the Arcadia Region of Mars; Isotopic Composition of Lunar Soils and the Early Differentiation of the Moon; Trace Element Analysis of Lunar Soils by ICP-MS; Highly Siderophile Elements and Osmium Isotope Systematics in Ureilites: Are the Carbonaceous Veins Primary Components?; Evaporative Evolution of Martian Brines Based on Halogens in Nakhlites and MER Samples; Io from High-Resolution Galileo PPR Data Taken Simultaneously with SSI or NIMS Observations; Loki, Io: Groundbased Observations and a Model for Periodic Overturn; Deconstructing a Few Myths in the Interpretation of Satellite-Altitude Crustal Magnetic Field: Examples from Mars Global Surveyor; Semi-Autonomous Rover Operations: A Mars Technology Program Demonstration; Rotational Studies of Asteroids with Small Telescopes; Mineralogy and Temperature-induced Spectral Investigations of A-type Asteroids 246 Asporina and 446 Aeternitas; and Thermal History Calculations Versus Full Convection Models: Application to the Thermal Evolution of Mercury. Recent Solar-Proton Fluxes
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7. Photocopy of engineering drawing. AETR DIGS FACILITY THEODOLITE AND ...
7. Photocopy of engineering drawing. AETR DIGS FACILITY THEODOLITE AND PRISM SHELTER: ELEVATIONS, FLOOR AND FOUNDATION PLANS, 1971. - Cape Canaveral Air Station, Launch Complex 17, Facility 28413, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL
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Del Dottore, Emanuela; Mondini, Alessio; Sadeghi, Ali; Mattoli, Virgilio; Mazzolai, Barbara
2017-12-22
This paper presents a comparative analysis in terms of energy required by an artificial probe to penetrate soil implementing two different strategies: a straight penetration movement and a circumnutation, which is an oscillatory movement performed by plant roots. The role of circumnutations in plant roots is still debated. We hypothesized that circumnutation movements can help roots in penetrating soil, and validated our assumption by testing the probe at three distinct soil densities and using various combinations of circumnutation amplitudes and periods for each soil. The comparison was based on the total work done by the system while circumnutating at its tip level with respect to that shown by the same system in straight penetration. The total energy evaluation confirmed an improvement obtained by circumnutations up to 33%. We also proposed a fitting model for our experimental data that was used to estimate energy needed by the probe to penetrate soil at different dimensions and circumnutation amplitudes. Results showed the existence of a trade-off among penetration velocity, circumnutation period, and amplitude toward an energy consumption optimization, expressed by the lead angle of the helical path that should stay in the range between 46° and 65°. Moreover, circumnutations with appropriate amplitude (~10°) and period (~80 s) values were more efficient than straight penetration also at different probe tip dimensions, up to a threshold diameter (from 2 mm to 55 mm). Based on the obtained results, we speculated that circumnutations can represent a strategy used by plant roots to reduce the pressure and energy needed to penetrate soil. The translation of this biological feature in robotic systems will allow improving their energetic efficiency in digging tasks, and thus open new scenarios for use in search and rescue, environmental monitoring, and soil exploration.
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Novara, Agata; Pisciotta, Antonino; Minacapilli, Mario; Maltese, Antonino; Capodici, Fulvio; Cerdà, Artemi; Gristina, Luciano
2018-05-01
Soil erosion processes in vineyards, beyond surface runoff and sediment transport, have a strong effect on soil organic carbon (SOC) loss and redistribution along the slope. Variation in SOC across the landscape can determine differences in soil fertility and vine vigor. The goal of this research was to analyze the interactions among vines vigor, sediment delivery and SOC in a sloping vineyard located in Sicily. Six pedons were studied along the slope by digging 6 pits up to 60cm depth. Soil was sampled every 10cm and SOC, water extractable organic carbon (WEOC) and specific ultraviolet absorbance (SUVA) were analyzed. Erosion rates, detachment and deposition areas were measured by the pole height method which allowed mapping of the soil redistribution. The vigor of vegetation, expressed as Normalized Difference Vegetation Index (NDVI), derived from high-resolution satellite multispectral data, was compared with measured pruning weight. Results confirmed that soil erosion, sediment redistribution and SOC across the slope was strongly affected by topographic features, slope and curvature. The erosion rate was 16Mgha -1 y -1 since the time of planting (6years). SOC redistribution was strongly correlated with the detachment or deposition areas as highlighted by pole height measurements. The off-farm SOC loss over six years amounted to 1.2MgCha -1 . SUVA 254 values, which indicate hydrophobic material rich in aromatic constituents of WEOC, decreased significantly along the slope, demonstrating that WEOC in the detachment site is more stable in comparison to deposition sites. The plant vigor was strongly correlated with WEOC constituents. Results demonstrated that high resolution passive remote sensing data combined with soil and plant analyses can survey areas with contrasting SOC, soil fertility, soil erosion and plant vigor. This will allow monitoring of soil erosion and degradation risk areas and support decision-makers in developing measures for friendly environmental management. Copyright © 2017 Elsevier B.V. All rights reserved.
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Space environment and lunar surface processes, 2
NASA Technical Reports Server (NTRS)
Comstock, G. M.
1982-01-01
The top few millimeters of a surface exposed to space represents a physically and chemically active zone with properties different from those of a surface in the environment of a planetary atmosphere. To meet the need or a quantitative synthesis of the various processes contributing to the evolution of surfaces of the Moon, Mercury, the asteroids, and similar bodies, (exposure to solar wind, solar flare particles, galactic cosmic rays, heating from solar radiation, and meteoroid bombardment), the MESS 2 computer program was developed. This program differs from earlier work in that the surface processes are broken down as a function of size scale and treated in three dimensions with good resolution on each scale. The results obtained apply to the development of soil near the surface and is based on lunar conditions. Parameters can be adjusted to describe asteroid regoliths and other space-related bodies.
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Numerical simulations of regolith sampling processes
NASA Astrophysics Data System (ADS)
Schäfer, Christoph M.; Scherrer, Samuel; Buchwald, Robert; Maindl, Thomas I.; Speith, Roland; Kley, Wilhelm
2017-07-01
We present recent improvements in the simulation of regolith sampling processes in microgravity using the numerical particle method smooth particle hydrodynamics (SPH). We use an elastic-plastic soil constitutive model for large deformation and failure flows for dynamical behaviour of regolith. In the context of projected small body (asteroid or small moons) sample return missions, we investigate the efficiency and feasibility of a particular material sampling method: Brushes sweep material from the asteroid's surface into a collecting tray. We analyze the influence of different material parameters of regolith such as cohesion and angle of internal friction on the sampling rate. Furthermore, we study the sampling process in two environments by varying the surface gravity (Earth's and Phobos') and we apply different rotation rates for the brushes. We find good agreement of our sampling simulations on Earth with experiments and provide estimations for the influence of the material properties on the collecting rate.
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Direct detection of projectile relics from the end of the lunar basin-forming epoch.
Joy, Katherine H; Zolensky, Michael E; Nagashima, Kazuhide; Huss, Gary R; Ross, D Kent; McKay, David S; Kring, David A
2012-06-15
The lunar surface, a key proxy for the early Earth, contains relics of asteroids and comets that have pummeled terrestrial planetary surfaces. Surviving fragments of projectiles in the lunar regolith provide a direct measure of the types and thus the sources of exogenous material delivered to the Earth-Moon system. In ancient [>3.4 billion years ago (Ga)] regolith breccias from the Apollo 16 landing site, we located mineral and lithologic relics of magnesian chondrules from chondritic impactors. These ancient impactor fragments are not nearly as diverse as those found in younger (3.4 Ga to today) regolith breccias and soils from the Moon or that presently fall as meteorites to Earth. This suggests that primitive chondritic asteroids, originating from a similar source region, were common Earth-Moon-crossing impactors during the latter stages of the basin-forming epoch.
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Demandite, lunar materials and space industrialization
NASA Technical Reports Server (NTRS)
Criswell, D. R.
1977-01-01
Terrestrial industry consumes a wide range of elements in producing the outputs which support and make industrial societies possible. 'Demandite' is a conceptual or synthetic molecule which is composed of the weight fractions of the major elements consumed by industry. Demandite needed for mature industrial activities in space will differ from the terrestrial composition because solar energy must replace hydrocarbon-energy, lunar and asteroidal bulk compositions are different from mineral deposits on the earth, and the major bulk processing in space will be the creation of radiation shielding for human habitats to provide real estate in space complete with water, atmosphere and life-stock elements. Demandite cost may be dominated by earth to deep space transport cost of minor elemental constituents depleted in the lunar soils unless careful attention is given to substitution of materials, searches of the moon (polar regions) and asteroids for the depleted elements, and continuing lowering of earth to deep space transport costs.
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6. Photocopy of engineering drawing. AETR DIGS FACILITY THEODOLITE AND ...
6. Photocopy of engineering drawing. AETR DIGS FACILITY THEODOLITE AND PRISM SHELTER: MONUMENT LOCATION AND LINE-OF-SIGHT PLAN, 1972. - Cape Canaveral Air Station, Launch Complex 17, Facility 28413, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL
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Identifying Extraplanar Diffuse Ionized Gas in a Sample of MaNGA Galaxies
NASA Astrophysics Data System (ADS)
Hubbard, Ryan J.; Diamond-Stanic, Aleksandar M.; MaNGA Team
2016-01-01
The efficiency with which galaxies convert gas into stars is driven by the continuous cycle of accretion and feedback processes within the circumgalactic medium. Extraplanar diffuse ionized gas (eDIG) can provide insights into the tumultuous processes that govern the evolution of galactic disks because eDIG emission traces both inflowing and outflowing gas. With the help of state-of-the-art, spatially-resolved spectroscopy from MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), we developed a computational method to identify eDIG based on the strength of and spatial extent of optical emission lines for a diverse sample of 550 nearby galaxies. This sample includes roughly half of the MaNGA galaxies that will become publicly available in summer 2016 as part of the Thirteenth Data Release of the Sloan Digital Sky Survey. We identified signatures of eDIG in 8% of the galaxies in this sample, and we found that these signatures are particularly common among galaxies with active star formation and inclination angles >45 degrees. Our analysis of the morphology, incidence, and kinematics of eDIG has important implications for current models of accretion and feedback processes that regulate star formation in galaxies. We acknowledge support from the Astrophysics REU program at the University of Wisconsin-Madison, the National Astronomy Consortium, and The Grainger Foundation.
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NASA Astrophysics Data System (ADS)
Donaldson Hanna, K. L.; Pieters, C. M.; Patterson, W., III; Moriarty, D.
2012-12-01
Remote sensing observations provide key insights into the composition and evolution of planetary surfaces. A fundamentally important component to any remote sensing study of planetary surfaces is laboratory measurements of well-characterized samples measured under the appropriate environmental conditions. The near-surface vacuum environment of airless bodies like the Moon and asteroids creates a thermal gradient in the upper hundred microns of regolith. Lab studies of particulate rocks and minerals as well as selected lunar soils under vacuum and lunar-like conditions have identified significant effects of this thermal gradient on thermal infrared (TIR) spectral measurements [e.g. Logan et al. 1973, Salisbury and Walter 1989, Thomas et al. 2010, Donaldson Hanna et al. 2012]. Compared to ambient conditions, these effects include: (1) the Christiansen feature (CF), an emissivity maximum diagnostic of mineralogy and average composition, shifts to higher wavenumbers and (2) an increase in spectral contrast of the CF relative to the Reststrahlen bands (RB), the fundamental molecular vibration bands due to Si-O stretching and bending. Such lab studies demonstrate the high sensitivity of TIR emissivity spectra to environmental conditions under which they are measured. The Asteroid and Lunar Environment Chamber (ALEC) is the newest addition to the RELAB at Brown University. The vacuum chamber simulates the space environment experienced by the near-surface soils of the Moon and asteroids. The internal rotation stage allows for six samples and two blackbodies to be measured without breaking vacuum (<10-4 mbar). Liquid nitrogen is used to cool the interior of the chamber, creating a cold, low emission environment (mimicking the space environment) for heated samples to radiate into. Sample cups can be heated in one of three configurations: (1) from below using heaters embedded in the base of the sample cup, (2) from above using a solar-like radiant heat source, and (3) from below and above to allow the magnitude of the thermal gradient to be examined. ALEC is connected to RELAB's Thermo Nicolet FTIR spectrometer which allows laboratory emissivity spectra to be collected at a resolution of 4 cm-1 over a nominal ~400 - 7400 cm-1 spectral range. An initial set of experiments have been run to understand how variations in the internal chamber pressure, power from the solar-like halogen lamp, and sample cup temperature affect spectral measurements of fine particulate (< 25 μm) mineral separates. These early results corroborate previous lab measurements showing the sensitivity of TIR spectra to the conditions under which they are measured and for the first time illustrates how the pressure and the thermal gradient each contribute to the changes in TIR spectral measurements. Spectral measurements of lunar soils under varying controlled conditions will be compared with Diviner data to understand how to accurately simulate conditions of the real near-surface environment of the Moon. Once conditions are constrained future spectral measurements will focus on building a spectral library of well-characterized minerals, rocks, soils, and meteorites measured under lunar environmental conditions. Such measurements are essential to interpret current TIR datasets like Diviner and future missions like OSIRIS-REx.
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NASA Astrophysics Data System (ADS)
Pett-Ridge, J.; McFarlane, K. J.; Heckman, K. A.; Reed, S.; Green, E. A.; Nico, P. S.; Tfaily, M. M.; Wood, T. E.; Plante, A. F.
2016-12-01
Tropical forest soils store more carbon (C) than any other terrestrial ecosystem and exchange vast amounts of CO2, water, and energy with the atmosphere. Much of this C is leached and stored in deep soil layers where we know little about its fate or the microbial communities that drive deep soil biogeochemistry. Organic matter (OM) in tropical soils appears to be associated with mineral particles, suggesting deep soils may provide greater C stabilization. However, few studies have evaluated sub-surface soils in tropical ecosystems, including estimates of the turnover times of deep soil C, the sensitivity of this C to global environmental change, and the microorganisms involved. We quantified bulk C pools, microbial communities, molecular composition of soil organic matter, and soil radiocarbon turnover times from surface soils to 1.5m depths in multiple soil pits across the Luquillo Experimental Forest, Puerto Rico. Soil C, nitrogen, and root and microbial biomass all declined exponentially with depth; total C concentrations dropped from 5.5% at the surface to <0.5% at 140cm depth. High-throughput sequencing highlighted distinct microbial communities in surface soils (Acidobacteria and Proteobacteria) versus those below the active rooting zone (Verrucomicrobia and Thaumarchaea). High resolution mass spectrometry (FTICR-MS) analyses suggest a shift in the composition of OM with depth (especially in the water soluble fraction), an increase in oxidation, and decreasing H/C with depth (indicating higher aromaticity). Additionally, surface samples were rich in lignin-like compounds of plant origin that were absent with depth. Soil OM 14C and mean turnover times were variable across replicate horizons, ranging from 3-1500 years at the surface, to 5000-40,000 years at depth. In comparison to temperate deciduous forests, these 14C values reflect far older soil C. Particulate organic matter (free light fraction), with a relatively modern 14C was found in low but measureable concentration in even the deepest soil horizons. Our results indicate these tropical subsoils contain small but metabolically active microbial communities that are highly OM limited and may persist via degradation of recent inputs.
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Briat, Arnaud; Slimani, Lotfi; Perret, Pascale; Villemain, Danièle; Halimi, Serge; Demongeot, Jacques; Fagret, Daniel; Ghezzi, Catherine
2007-11-01
Insulin resistance, implying depressed cellular sensitivity to insulin, is a risk factor for type 2 diabetes and cardiovascular disease. This study is the first step towards the development of a technique of insulin resistance measurement in humans with a new tracer of glucose transport, [(123)I]6-deoxy-6-iodo-D-glucose (6DIG). We investigated 6DIG kinetics in anaesthetised control rats and in three models of insulin-resistant rats: fructose fed, Zucker and ZDF. The study of myocardial 6DIG activity was performed under two conditions: first, 6DIG was injected under the baseline condition and then it was injected after a bolus injection of insulin. After each injection, radioactivity was measured over 45 min by external detection via NaI probes, in the heart and blood. A tri-compartment model was developed to obtain fractional transfer coefficients of 6DIG from the blood to the heart. These coefficients were significantly increased with insulin in control rats and did not change significantly in insulin-resistant rats. The ratio of the coefficient obtained under insulin to that obtained under basal conditions gave an index of cardiac insulin resistance for each animal. The mean values of these ratios were significantly lower in insulin-resistant than in control rats: 1.16 +/- 0.06 vs 2.28 +/- 0.18 (p < 0.001) for the fructose-fed group, 0.92 +/- 0.05 vs 1.62 +/- 0.25 (p < 0.01) for the Zucker group and 1.34 +/- 0.06 vs 2.01 +/- 0.26 (p < 0.05) for the ZDF group. These results show that 6DIG could be a useful tracer to image cardiac insulin resistance.
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Jackson, Alexander G S; Leu, Szu-Yun; Ford, Neil B; Hicks, James W
2015-11-01
Snakes exhibit large factorial increments in oxygen consumption during digestion and physical activity, and long-lasting sub-maximal increments during reproduction. Under natural conditions, all three physiological states may occur simultaneously, but the integrated response is not well understood. Adult male and female checkered gartersnakes (Thamnophis marcianus) were used to examine increments in oxygen consumption (i.e. V̇(O2)) and carbon dioxide production (i.e. V̇(CO2)) associated with activity (Act), digestion (Dig) and post-prandial activity (Act+Dig). For females, we carried out these trials in the non-reproductive state, and also during the vitellogenic (V) and embryogenic (E) phases of a reproductive cycle. Endurance time (i.e. time to exhaustion, TTE) was recorded for all groups during Act and Act+Dig trials. Our results indicate that male and non-reproductive female T. marcianus exhibit significant increments in V̇(O2) during digestion (∼5-fold) and activity (∼9-fold), and that Act+Dig results in a similar increment in V̇(O2) (∼9- to 10-fold). During reproduction, resting V̇(O2) increased by 1.6- to 1.7-fold, and peak increments during digestion were elevated by 30-50% above non-reproductive values, but values associated with Act and Act+Dig were not significantly different from non-reproductive values. During Act+Dig, endurance time remained similar for all of the groups in the present study. Overall, our results indicate that prioritization is the primary pattern of interaction in oxygen delivery exhibited by this species. We propose that the metabolic processes associated with digestion, and perhaps reproduction, are temporarily compromised during activity. © 2015. Published by The Company of Biologists Ltd.
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Cohesion of Mm- to Cm-Sized Asteroid Simulant Grains: An Experimental Study
NASA Astrophysics Data System (ADS)
Brisset, Julie; Colwell, Joshua E.; Dove, Adrienne; Jarmak, Stephanie; Anderson, Seamus
2017-10-01
The regolith covering the surfaces of asteroids and planetary satellites is very different from terrestrial soil particles and subject to environmental conditions very different from what is found on Earth. The loose, unconsolidated granular material has angular-shaped grains and a broad size distribution. On small and airless bodies (<10 km), the solar wind leads to a depletion of fine grains (<100µm) on the surface. Ground observations of the two asteroids currently targeted by spacecraft, Ryugu (Hayabusa-2) and Bennu (OSIRIS-REx), indicate that their surfaces could be covered in mm- to cm-sized regolith grains. As these small bodies have surface gravity levels below 10-5g, g being the Earth surface gravity, the cohesion behavior of the regolith grains will dictate the asteroid’s surface morphology and its response to impact or spacecraft contact.Previous laboratory experiments on low-velocity impacts into regolith simulant with grain sizes <250 µm have revealed a transition of the grain behavior from a gravity-dominated regime to a cohesion-dominated regime when the local gravity level reaches values below 10-3g. This is in good agreement with analytical and simulation studies for these grain sizes. From the expected grain sizes at the surfaces of Ryugu and Bennu, we have now focused on larger grain sizes ranging from mm to cm. We have carried out a series of experiments to study the cohesion behavior of such larger grains of asteroid regolith simulant. The simulant used was CI Orgueil of Deep Space Industries. Experiments included laboratory tabletop avalanching, compression and shear force measurements, as well as low-velocity impacts under microgravity.Our goal is to determine if the grain size distribution has an influence on the cohesion behavior of the regolith and if we can validate numerical simulation results with experimental measurements. We will discuss the implications of our results for sample return or landing missions to small bodies such as asteroids or Martian moons.
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In-Situ Water Vapor Probe for a Robot Arm-Mounted, Compact Water Vapor Analyzer: Preliminary Results
NASA Technical Reports Server (NTRS)
Socki, Richard A.; Niles, Paul B.; Cabiran, Mike; Rossi, Chris; Sun, Tao
2013-01-01
This work describes the ongoing development of an instrument package for the in-situ detection and isotopic analysis of water (from ice, icy soils, and hydrated minerals) on future lunar, asteroid, or martian exploration missions. This instrument is intended to be mounted on a robotic arm and be brought to the sample, rather than necessitating expensive and complicated sample handling to bring the sample to the instrument.
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NASA Technical Reports Server (NTRS)
Ignatiev, A.
2000-01-01
Contents include following: Developing Technologies for Space Resource Utilization - Concept for a Planetary Engineering Research Institute. Results of a Conceptual Systems Analysis of Systems for 200 m Deep Sampling of the Martian Subsurface. The Role of Near-Earth Asteroids in Long-Term Platinum Supply. Core Drilling for Extra-Terrestrial Mining. Recommendations by the "LSP and Manufacturing" Group to the NSF-NASA Workshop on Autonomous Construction and Manufacturing for Space Electrical Power Systems. Plasma Processing of Lunar and Planetary Materials. Percussive Force Magnitude in Permafrost. Summary of the Issues Regarding the Martian Subsurface Explorer. A Costing Strategy for Manufacturing in Orbit Using Extraterrestrial Resources. Mine Planning for Asteroid Orebodies. Organic-based Dissolution of Silicates: A New Approach to Element Extraction from LunarRegohth. Historic Frontier Processes Active in Future Space-based Mineral Extraction. The Near-Earth Space Surveillance (NIESS) Mission: Discovery, Tracking, and Characterization of Asteroids, Comets, and Artificial Satellites with a microsatellite. Privatized Space Resource Property Ownership. The Fabrication of Silicon Solar Cells on the Moon Using In-Situ Resources. A New Strategy for Exploration Technology Development: The Human Exploration and Development of Space (HEDS) Exploratiori/Commercialization Technology Initiative. Space Resources for Space Tourism. Recovery of Volatiles from the Moon and Associated Issues. Preliminary Analysis of a Small Robot for Martian Regolith Excavation. The Registration of Space-based Property. Continuous Processing with Mars Gases. Drilling and Logging in Space; An Oil-Well Perspective. LORPEX for Power Surges: Drilling, Rock Crushing. An End-To-End Near-Earth Asteroid Resource Exploitation Plan. An Engineering and Cost Model for Human Space Settlement Architectures: Focus on Space Hotels and Moon/Mars Exploration. The Development and Realization of a Silicon-60-based Economy in CisLunar Space. Our Lunar Destiny: Creating a Lunar Economy. Cost-Effective Approaches to Lunar Passenger Transportation. Lunar Mineral Resources: Extraction and Application. Space Resources Development - The Link Between Human Exploration and the Long-term Commercialization of Space. Toward a More Comprehensive Evaluation of Space Information. Development of Metal Casting Molds by Sol-Gel Technology Using Planetary Resources. A New Concept in Planetary Exploration: ISRU with Power Bursts. Bold Space Ventures Require Fervent Public Support. Hot-pressed Iron from Lunar Soil. The Lunar Dust Problem: A Possible Remedy. Considerations on Use of Lunar Regolith in Lunar Constructions. Experimental Study on Water Production by Hydrogen Reduction of Lunar Soil Simulant in a Fixed Bed Reactor.
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Spike-In Normalization of ChIP Data Using DNA-DIG-Antibody Complex.
Eberle, Andrea B
2018-01-01
Chromatin immunoprecipitation (ChIP) is a widely used method to determine the occupancy of specific proteins within the genome, helping to unravel the function and activity of specific genomic regions. In ChIP experiments, normalization of the obtained data by a suitable internal reference is crucial. However, particularly when comparing differently treated samples, such a reference is difficult to identify. Here, a simple method to improve the accuracy and reliability of ChIP experiments by the help of an external reference is described. An artificial molecule, composed of a well-defined digoxigenin (DIG) labeled DNA fragment in complex with an anti-DIG antibody, is synthesized and added to each chromatin sample before immunoprecipitation. During the ChIP procedure, the DNA-DIG-antibody complex undergoes the same treatments as the chromatin and is therefore purified and quantified together with the chromatin of interest. This external reference compensates for variability during the ChIP routine and improves the similarity between replicates, thereby emphasizing the biological differences between samples.
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2012-05-23
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center Visitor Complex in Florida, the For Inspiration and Recognition of Science and Technology FIRST Argos Team 1756 robot from Limestone Community, Brimfield and Richwoods High Schools in Peoria, Ill., is on display in Caterpillar’s sponsor booth at NASA’s Lunabotics Mining Competition. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. For more information, visit www.nasa.gov/lunabotics. Photo credit: NASA/Frankie Martin
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2017 Robotic Mining Competition
2017-05-23
Team Raptor members from the University of North Dakota College of Engineering and Mines check their robot, named "Marsbot," in the RoboPit at NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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2017 Robotic Mining Competition
2017-05-24
Derrick Matthews, left, with Kennedy Space Center's Communication and Public Engagement Directorate, and Kurt Leucht, event emcee, provide commentary at the mining arena during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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2017 Robotic Mining Competition
2017-05-24
Team members from West Virginia University prepare their mining robot for a test run in a giant sandbox before their scheduled mining run in the arena during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition Awards Ceremony
2017-05-26
Inside the Apollo-Saturn V Center at NASA's Kennedy Space Center Visitor Complex in Florida, teams from the 8th Annual Robotic Mining Competition eat dinner before the awards ceremony begins. More than 40 student teams from colleges and universities around the U.S. used their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26 at the visitor complex. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition - Activities
2018-05-17
Team members from Case Western Reserve University pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from The University of Utah pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
First-time participants from Saginaw Valley State University pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
On the second day of NASA's 9th Robotic Mining Competition, May 15, team members from Temple University work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
Team members from the University of Colorado at Boulder pause with their robot miner outside of the mining arena on the third day of NASA's 9th Robotic Mining Competition, May 16, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
On the third day of NASA's 9th Robotic Mining Competition, May 16, team members from Temple University prepare their robot miner for its turn in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
On the third day of NASA's 9th Robotic Mining Competition, May 16, team members prepare their robot miner for its turn in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from The University of Alabama pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
On the third day of NASA's 9th Robotic Mining Competition, May 16, team members from the University of Portland prepare their robot miner for its turn in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from the South Dakota School of Mines & Technology pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
On the third day of NASA's 9th Robotic Mining Competition, May 16, a university team cleans their robot miner after its turn in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
Team members from Iowa State University prepare their robot miner on the second day of NASA's 9th Robotic Mining Competition, May 15, in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
On the third day of NASA's 9th Robotic Mining Competition, May 16, team members from the University of Portland pause with their robot miner before its turn in the mining arena at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Setup
2018-05-14
On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, college team members work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-16
Team members from New York University prepare their robot miner for its turn in the mining arena on the third day of NASA's 9th Robotic Mining Competition, May 16, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from New York University work on their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from York College CUNY are with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from the University of Arkansas pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Near Earth Asteroids- Prospection, Orbit Modification and Mining
NASA Astrophysics Data System (ADS)
Grandl, W.; Bazso, A.
2014-04-01
The number of known Near Earth Asteroids (NEAs) has increased continuously during the last decades. Now we understand the role of asteroid impacts for the evolution of life on Earth. To ensure that mankind will survive in the long run, we have to face the "asteroid threat" seriously. On one hand we will have to develop methods of detection and deflection for Hazardous Asteroids, on the other hand we can use these methods to modify their orbits and exploit their resources. Rare-earth elements, rare metals like platinum group elements, etc. may be extracted more easily from NEAs than from terrestrial soil, without environmental pollution or political and social problems. In a first step NEAs, which are expected to contain resources like nickel-iron, platinum group metals or rare-earth elements, will be prospected by robotic probes. Then a number of asteroids with a minimum bulk density of 2 g/cm^3 and a diameter of 150 to 500 m will be selected for mining. Given the long duration of an individual mission time of 10-20 years, the authors propose a "pipeline" concept. While the observation of NEAs can be done in parallel, the precursor missions of the the next phase can be launched in short intervals, giving time for technical corrections and upgrades. In this way a continuous data flow is established and there are no idle times. For our purpose Potentially Hazardous Asteroids (PHAs) seem to be a favorable choice for the following reasons: They have frequent closeencounters to Earth, their minimum orbit intersection distance is less than 0.05 AU (Astronomic Units) and they have diameters exceeding 150 meters. The necessary velocity change (delta V) for a spaceship is below 12 km/s to reach the PHA. The authors propose to modify the orbits of the chosen PHAs by orbital maneuvers from solar orbits to stable Earth orbits beyond the Moon. To change the orbits of these celestial bodies it is necessary to develop advanced propulsion systems. They must be able to deliver high thrust and specific impulse to move the huge masses of the asteroids. Such a propulsion system could be the Bussard Fusion System, also known as the quiet-electricdischarge (QED) engine. It uses electrostatic fusion devices to generate electrical power. The fuel consists of Deuterium and Helium3 that are fusing to Helium4 plus protons releasing 18.3 MeV of energy per reaction. The charged protons escape from the confinement; their kinetic energy can be converted to electricity or be used directly as a plasma beam for generating thrust. For the reaction a specific energy of 3.5x1014 Joule/kg can be computed, i.e. orders-ofmagnitude higher than for any existing propulsion system. As an example we take the Asteroid with the designation 2008 EV5. It is classified as an Aten group asteroid with a mean diameter of 450 meters and belongs to spectral type S (stony asteroids). Our mass estimate (using a bulk density of 3 g/cm^3) is 1.4x1011 kg. To transfer 2008 EV5 to an Earth-like orbit the energy required is estimated to be in the order of 2.8x1018 Joule. This is the difference in Kepler energy between the NEA's current orbit and the Earth's orbit around the sun. Using the Bussard Fusion System the amount of fuel would be approx. 8000 kg of Helium3. To move an asteroid by remote control the authors propose to design unmanned space tugs which are propelled by Bussard Fusion Engines. A pair of space tugs is docked to each asteroid using drilling anchors. The fusion engines of the tugs then apply the thrust forces for the maneuvers. The first tug, which carries the main fuel quantity, applies the primary force for the orbital maneuvers. The second one adjust the flight track by short engine thrusts.
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NASA Technical Reports Server (NTRS)
McKay, David
2009-01-01
The lunar regolith consists of about 90% submillimeter particles traditionally termed lunar soil. The remainder consists of larger particles ranging up to boulder size rocks. At the lower size end, soil particles in the 10s of nanometer sizes are present in all soil samples. Lunar regolith overlies bedrock which consists of either lava flows in mare regions or impact-produced megaregolith in highland regions. Lunar regolith has been produced over billions of years by a combination of breaking and communition of bedrock by meteorite bombardment coupled with a variety of complex space weathering processes including solar wind implantation, solar flare and cosmic ray bombardment with attendant radiation damage, melting, vaporization, and vapor condensation driven by impact, and gardening and turnover of the resultant soil. Lunar regolith is poorly sorted compared to most terrestrial soils, and has interesting engineering properties including strong grain adhesion, over-compacted soil density, an abundance of agglutinates with sharp corners, and a variety of properties related to soil maturity. The NASA program has supported a variety of engineering test research projects, the production of bricks by solar or microwave sintering, the production of concrete, the in situ sintering and glazing of regolith by microwave, and the extraction of useful resources such as oxygen, hydrogen, iron, aluminum, silicon and other products. Future requirements for a lunar surface base or outpost will include construction of protective berms, construction of paved roadways, construction of shelters, movement and emplacement of regolith for radiation shielding and thermal control, and extraction of useful products. One early need is for light weight but powerful digging, trenching, and regolith-moving equipment.
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Mancuso, Raffaella; Pomelli, Christian C; Malafronte, Francesco; Maner, Asif; Marino, Nadia; Chiappe, Cinzia; Gabriele, Bartolo
2017-06-07
The regiochemical outcome of the iodolactonization of 2-alkynylbenzoic acids, carried out at 100 °C in ionic liquids (ILs) as unconventional solvents and with molecular iodine as the iodine source, in the absence of external bases, was found to be strongly dependent on the nature of the IL medium. In particular, while the use of N-ethyl-N-methylmorpholinium dicyanamide (Mor 1,2 N(CN) 2 ) promoted the stereoselective formation of (E)-3-(iodomethylene)isobenzofuran-1(3H)-ones, through an anti-5-exo-dig cyclization route, the use of 1-ethyl-3-methylimidazolium ethyl sulfate (EmimEtSO 4 ) tended to favor the 6-endo-dig cyclization mode, with preferential or selective formation of 4-iodo-1H-isochromen-1-ones. In any case, the IL solvent could be easily recycled after extraction of the product from the reaction mixture with diethyl ether. DFT calculations have been carried out to clarify the role of the IL's nature in favoring either the anti-5-exo-dig cyclization route or the 6-endo-dig mode. In the case of iodocyclization of 2-ethynylbenzoic acid, only the 5-exo-dig mode was observed in both EmimEtSO 4 and Mor 1,2 N(CN) 2 solvents. The structures of two representative products have been confirmed by X-ray diffraction analysis.
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NASA Astrophysics Data System (ADS)
Matys, M.; Kaneki, S.; Nishiguchi, K.; Adamowicz, B.; Hashizume, T.
2017-12-01
We proposed that the disorder induced gap states (DIGS) can be responsible for the threshold voltage (Vth) instability in Al2O3/AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors. In order to verify this hypothesis, we performed the theoretical calculations of the capacitance voltage (C-V) curves for the Al2O3/AlGaN/GaN structures using the DIGS model and compared them with measured ones. We found that the experimental C-V curves with a complex hysteresis behavior varied with the maximum forward bias and the sweeping rate can be well reproduced theoretically by assuming a particular distribution in energy and space of the DIGS continuum near the Al2O3/AlGaN interface, i.e., a U-shaped energy density distribution and exponential depth decay from the interface into Al2O3 layer (up to 4 nm), as well as suitable DIGS capture cross sections (the order of magnitude of 10-15 cm2). Finally, we showed that the DIGS model can also explain the negative bias induced threshold voltage instability. We believe that these results should be critical for the successful development of the passivation techniques, which allows to minimize the Vth instability related effects.
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Digging into Archaeology Projects.
ERIC Educational Resources Information Center
Grambo, Greg
1996-01-01
Suggestions are offered for a classroom project of planning and conducting an archaeological dig on or near school property. Principles of archaeological practice such as making drawings of the site and using a grid frame to record locations are explained. Also suggested is a simulation activity in which students pick imbedded "findings" out of…
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49 CFR 180.411 - Acceptable results of tests and inspections.
Code of Federal Regulations, 2011 CFR
2011-10-01
... than that prescribed in the applicable specification. (b) Dents, cuts, digs and gouges. For evaluation... minimum thickness remaining beneath a cut, dig, or gouge may not be less than that prescribed in the... to hazardous materials service. (e) Relief valves. Any pressure relief valve that fails to open and...
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Extraction of Volatiles from Regolith or Soil on Mars, the Moon, and Asteroids
NASA Technical Reports Server (NTRS)
Linne, Diane; Kleinhenz, Julie; Trunek, Andrew; Hoffman, Stephen; Collins, Jacob
2017-01-01
NASA's Advanced Exploration Systems ISRU Technology Project is evaluating concepts to extract water from all resource types Near-term objectives: Produce high-fidelity mass, power, and volume estimates for mining and processing systems Identify critical challenges for development focus Begin demonstration of component and subsystem technologies in relevant environment Several processor types: Closed processors either partially or completely sealed during processing Open air processors operates at Mars ambient conditions In-situ processors Extract product directly without excavation of raw resource Design features Elimination of sweep gas reduces dust particles in water condensate Pressure maintained by height of soil in hopper Model developed to evaluate key design parameters Geometry: conveyor diameter, screw diameter, shaft diameter, flight spacing and pitch Operational: screw speed vs. screw length (residence time) Thermal: Heat flux, heat transfer to soil Testing to demonstrate feasibility and performance Agglomeration, clogging Pressure rise forced flow to condenser.
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NASA Technical Reports Server (NTRS)
Taylor, Lawrence A.; Pieters, Carle; McKay, David S.
1998-01-01
Inferences about the igneous and impact evolution of planetary bodies are based upon spectral remote sensing of their surfaces. However, it is not the rocks of a body that are seen by the remote sensing, but rather the regolith, that may contain small pieces of rock but also many other phases as well. Indeed, recent flybys of objects even as small as asteroid Ida have shown that these objects are covered by a regolith. Thus, spectral properties cannot be directly converted into information about the igneous history of the object. It is imperative to fully understand the nature of the regolith, particularly its finer fraction termed "soil," to appreciate the possible effects of "space weathering" on the reflectance spectra. We have initiated a study of our nearest, regolith-bearing body, the Moon, as "ground truth" for further probes of planetary and asteroidal surfaces. the foundation for remote chemical and mineralogical analyses lies in the physics underlying optical absorption and the linking of spectral properties of materials measured in the laboratory to well understood mineral species and their mixtures. From this statement, it is obvious that there should be a thorough integration of the material science of lunar rocks and soils with the remote-sensing observations. That is, the lunar samples returned by the Apollo missions provide a direct means for evaluation of spectral characteristics of the Moon. However, this marriage of the remote-sensing and lunar sample communities has suffered from a prolonged unconsummated betrothal, nurtured by an obvious complacency by both parties. To make more direct and quantitative links between soil chemistry/mineralogy and spectral properties, we have initiated a program to (1) obtain accurate characterization of the petrography of lunar soils (in terms relevant to remote analyses), coupled with (2) measurement of precise reflectance spectra, with testing and use of appropriate analytical tools that identify and characterize individual mineral and glass components. It is the finest-sized fractions of the bulk lunar soil that dominate the observed spectral signatures.
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Space Weathering Effects at UV Wavelengths: Asteroids and the Moon
NASA Astrophysics Data System (ADS)
Hendrix, Amanda; Vilas, F.
2006-09-01
Space weathering, the bombardment of airless bodies by micrometeoroids and irradiation by solar wind particles, affects spectra of solar system bodies at visible/near IR (VNIR) wavelengths by darkening and reddening their surface materials, as well as degrading absorption features. We present new results detailing space weathering effects at ultraviolet wavelengths. We focus on new spectral modeling results, and also present spacecraft data of asteroids and the Moon, along with new UV measurements of asteroid families from HST, to demonstrate the effects of varying degrees of weathering and the outcome of weathering on surfaces of different compositions. Weathered surfaces are relatively bright and spectrally blue in the UV; these UV effects can be more obvious than the VNIR effects. The cause of these weathering effects is likely vapor deposition of submicroscopic iron (SMFe), through solar wind irradiation and micrometeoroid bombardment of the bodies' surfaces. In silicate minerals, the NUV region is dominated by a decrease in reflectance with wavelength - the "UV absorption edge.” In contrast to silicates, iron is opaque and relatively bright in the UV, so the addition of SMFe to a silicate grains has the effect of making the UV region brighter; this is in opposition to the situation at longer wavelengths, where the addition of SMFe decreases the albedo. Our spectral modeling results show that the addition of SMFe decreases the steepness of the UV dropoff, in effect making the UV spectrum bluer. This can explain the difference in UV spectral behavior seen between S-class asteroids and less-weathered ordinary chondrite meteorites, and between lunar rocks and more weathered lunar soils. This work is funded in part by Hubble Space Telescope Grant #10557.
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Microwave Extraction of Water from Lunar Regolith Simulant
NASA Technical Reports Server (NTRS)
Ethridge, Edwin C.; Kaukler, William
2007-01-01
Nearly a decade ago the DOD Clementine lunar orbital mission obtained data indicating that the permanently shaded regions at the lunar poles may have permanently frozen water in the lunar soil. Currently NASA's Robotic Lunar Exploration Program, RLEP-2, is planned to land at the lunar pole to determine if water is present. The detection and extraction of water from the permanently frozen permafrost is an important goal for NASA. Extraction of water from lunar permafrost has a high priority in the In-Situ Resource Utilization, ISRU, community for human life support and as a fuel. The use of microwave processing would permit the extraction of water without the need to dig, drill, or excavate the lunar surface. Microwave heating of regolith is potentially faster and more efficient than any other heating methods due to the very low thermal conductivity of the lunar regolith. Also, microwaves can penetrate into the soil permitting water removal from deep below the lunar surface. A cryogenic vacuum test facility was developed for evaluating the use of microwave heating and water extraction from a lunar regolith permafrost simulant. Water is obtained in a cryogenic cold trap even with soil conditions below 0 C. The results of microwave extraction of water experiments will be presented.
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NASA Technical Reports Server (NTRS)
1970-01-01
The concept development, testing, evaluation, and the selection of a final wheel design concept for a dual-mode lunar surface vehicle (DLRV) is detailed. Four wheel configurations were fabricated (one open wheel and three closed wheel) (and subjected to a series of soft soil, mechanical, and endurance tests. Results show that the open wheel has lower draw-bar pull (slope climbing) capability in loose soil due to its higher ground pressure and tendency to dig in at high wheel slip. Endurance tests indicate that a double mesh, fully enclosed wheel can be developed to meet DLRV life requirements. There is, however, a 1.0 to 1.8 lb/wheel weight penalty associated with the wheel enclosure. Also the button cleats used as grousers for the closed-type wheels result in local stress concentration and early fatigue failure of the wire mesh. Load deflection tests indicate that the stiffness of the covered wheel increased by up to 50% after soil bin testing, due to increased friction between the fabric and the wire mesh caused by the sand. No change in stiffness was found for the open wheel. The single woven mesh open wheel design with a chevron tread is recommended for continued development
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Scribing Work Songs at an Archeological Dig in Egypt
ERIC Educational Resources Information Center
Poppe, Donna
2011-01-01
This article reports research conducted in the northeastern corner of Egypt's Nile Delta during an excavation at the Mendes archeological dig site in July-August, 2007. Donald Redford, Professor at Pennsylvania State University, accepted the author as the only nonarcheologist that year. In addition to duties of measuring, registering, and storing…
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Barczi, Jean-François; Rey, Hervé; Griffon, Sébastien; Jourdan, Christophe
2018-04-18
Many studies exist in the literature dealing with mathematical representations of root systems, categorized, for example, as pure structure description, partial derivative equations or functional-structural plant models. However, in these studies, root architecture modelling has seldom been carried out at the organ level with the inclusion of environmental influences that can be integrated into a whole plant characterization. We have conducted a multidisciplinary study on root systems including field observations, architectural analysis, and formal and mathematical modelling. This integrative and coherent approach leads to a generic model (DigR) and its software simulator. Architecture analysis applied to root systems helps at root type classification and architectural unit design for each species. Roots belonging to a particular type share dynamic and morphological characteristics which consist of topological and geometric features. The DigR simulator is integrated into the Xplo environment, with a user interface to input parameter values and make output ready for dynamic 3-D visualization, statistical analysis and saving to standard formats. DigR is simulated in a quasi-parallel computing algorithm and may be used either as a standalone tool or integrated into other simulation platforms. The software is open-source and free to download at http://amapstudio.cirad.fr/soft/xplo/download. DigR is based on three key points: (1) a root-system architectural analysis, (2) root type classification and modelling and (3) a restricted set of 23 root type parameters with flexible values indexed in terms of root position. Genericity and botanical accuracy of the model is demonstrated for growth, branching, mortality and reiteration processes, and for different root architectures. Plugin examples demonstrate the model's versatility at simulating plastic responses to environmental constraints. Outputs of the model include diverse root system structures such as tap-root, fasciculate, tuberous, nodulated and clustered root systems. DigR is based on plant architecture analysis which leads to specific root type classification and organization that are directly linked to field measurements. The open source simulator of the model has been included within a friendly user environment. DigR accuracy and versatility are demonstrated for growth simulations of complex root systems for both annual and perennial plants.
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The Glinka Memorial Soil Monolith Collection: a treasure of Soil Science
NASA Astrophysics Data System (ADS)
Muggler, C. C.; Spaargaren, O.; Hartemink, A. E.
2012-04-01
The first World Congress of Soil Science, held in 1927 in Washington DC, USA, had as one of its highlights the exposition of soils from all over the world. The Russian delegation had planned the presentation of 50 soil monoliths. The soil profiles were collected under the supervision of Konstantin D. Glinka, then director of the Leningrad Agricultural Institute. The soil profiles included a geographical sequence form St Petersburg to the Caucasus and soils from Georgia, Azerbaijan, Kazakhstan, the Amu Darya region and the Siberian Far East. Due to shipping problems they did not arrive on time for the congress, and ended up in an USDA storage facility, where they remained untouched in their original wooden boxes. At first congress Glinka gave a lecture on Dokuchaev's ideas and the Russian developments on soil science, and joined the transcontinental field trip of 30 days that followed the congress. At that congress, Glinka was elected president of the International Soil Science Society, and was in charge to organize the next congress in Russia. However, he passed away a few months after the congress. In the 1970s, after a consultation with Wim Sombroek, then director of the International Soil Museum (ISM) in the Netherlands, the collection was donated to ISRIC by the US Soil Conservation Service. The soil profiles were shipped over in 1980 to become part of the collection of the Museum. The collection was named as "Glinka Memorial Collection" in agreement with the Dokuchaev Soil Institute, Moscow and the U.S. Soil Conservation Service, Washington. The monoliths were treated with a sugar solution by the Russians before shipment to the USA, this way keeping a good preservation quality. They were aimed for a single exhibition and for that they were poorly documented and lacked additional samples. In the early 1990s a project for revisit the sites was set up and six sites around St Petersburg were sampled for a comparative study of the soils within a time span of 70 years of great environmental change. The Glinka Memorial Collection is a special collection of the World Soil Museum, a scientific and historical treasure that offers possibilities to dig into the history of soil science and the history of the soils themselves.
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Mellon, M.T.; Boynton, W.V.; Feldman, W.C.; Arvidson, R. E.; Titus, Joshua T.N.; Bandfield, L.; Putzig, N.E.; Sizemore, H.G.
2009-01-01
We review multiple estimates of the ice table depth at potential Phoenix landing sites and consider the possible state and distribution of subsurface ice. A two-layer model of ice-rich material overlain by ice-free material is consistent with both the observational and theoretical lines of evidence. Results indicate ground ice to be shallow and ubiquitous, 2-6 cm below the surface. Undulations in the ice table depth are expected because of the thermodynamic effects of rocks, slopes, and soil variations on the scale of the Phoenix Lander and within the digging area, which can be advantageous for analysis of both dry surficial soils and buried ice-rich materials. The ground ice at the ice table to be sampled by the Phoenix Lander is expected to be geologically young because of recent climate oscillations. However, estimates of the ratio of soil to ice in the ice-rich subsurface layer suggest that that the ice content exceeds the available pore space, which is difficult to reconcile with existing ground ice stability and dynamics models. These high concentrations of ice may be the result of either the burial of surface snow during times of higher obliquity, initially high-porosity soils, or the migration of water along thin films. Measurement of the D/H ratio within the ice at the ice table and of the soil-to-ice ratio, as well as imaging ice-soil textures, will help determine if the ice is indeed young and if the models of the effects of climate change on the ground ice are reasonable. Copyright 2008 by the American Geophysical Union.
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ISRU Soil Mechanics Vacuum Facility: Soil Bin Preparation and Simulant Strength Characterization
NASA Technical Reports Server (NTRS)
Kleinhenz, Julie; Wilkinson, Allen
2012-01-01
Testing in relevant environments is key to exploration mission hardware development. This is true on both the component level (in early development) and system level (in late development stages). During ISRU missions the hardware will interface with the soil (digging, roving, etc) in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, conditioned simulant bed. However, in earth-based granular media, such as lunar soil simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. The Vacuum Facility #13, a mid-size chamber (3.66m tall, 1.5m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64m deep by 0.914m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types have been used. An electric cone penetrometer was used to measure simulant strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5Torr, regardless of the pump rate. However, slow off gassing of the soil lead to long test times, a full week, to reach 10-5Torr. This work highlights the need for robotic machine-simulant hardware and operations in vacuum to expeditiously perform (sub-)systems tests.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
NASA Kennedy Space Center Director Bob Cabana welcomes college and university teams to NASA's 9th Robotic Mining Competition, May 15, during the opening ceremony in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Media Day
2017-05-25
NASA Kennedy Space Center Director Bob Cabana, at right, talks with Ken Kremer, Universe Today, during media day at the agency's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Cabana shared his thoughts about the competition and the progress made to make Kennedy a multi-user spaceport. Teams from colleges and universities around the U.S. used their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition Awards Ceremony
2017-05-26
Undergraduate and graduate students with teams that participated in NASA's 8th Annual Robotic Mining Competition eat dinner in the Apollo-Saturn V Center at NASA's Kennedy Space Center Visitor Complex in Florida, before the awards ceremony. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26 at the visitor complex. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition - Media Day
2017-05-25
Lilliana Villareal, Spacecraft and Offline Operations manager in the Ground Systems Development and Operations Program, is interviewed on-camera by Al Feinberg, with the Communications and Public Engagement Directorate, during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition Awards Ceremony
2017-05-26
Inside the Apollo-Saturn V Center at the Kennedy Space Center Visitor Complex in Florida, Pat Simpkins, director of the Engineering Directorate at Kennedy Space Center, speaks to the teams during the award ceremony for NASA's 8th Annual Robotic Mining Competition. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26, at the visitor complex. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition Awards Ceremony
2017-05-26
Inside the Apollo-Saturn V Center at the Kennedy Space Center Visitor Complex in Florida, Lisa May, with Murphian Systems, presents the Judges Innovation Award during the award ceremony for NASA's 8th Annual Robotic Mining Competition. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26, at the visitor complex. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition Awards Ceremony
2017-05-26
Kurt Leucht, a NASA engineer and event emcee, welcomes guests to the awards ceremony for NASA's 8th Annual Robotic Mining Competition in the Apollo-Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26 at the visitor complex. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition - Media Day
2017-05-25
Stan Starr, branch chief for Applied Physics in the Exploration Research and Technology Programs, is interviewed on-camera by Sarah McNulty, with the Communication and Public Engagement Directorate, during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
A flag presentation and singing of the National Anthem are part of the opening ceremony of NASA's 9th Robotic Mining Competition, May 15, in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Setup
2018-05-14
On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, team members from the University of Minnesota-Twin Cities work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
On the second day of NASA's 9th Robotic Mining Competition, May 15, the RoboPits in the Educatory Resource Center at Kennedy Space Center Visitor Complex in Florida is filled with teams of students working on their uniquely designed robot miners. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
On the second day of NASA's 9th Robotic Mining Competition, May 15, team members from the University of Tulsa work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Setup
2018-05-14
On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, team members from the South Dakota School of Mines & Technology work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Setup
2018-05-14
On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, team members from Montana Tech of the University of Montana work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from York College CUNY make adjustments to their robot miner for its turn in the mining arena on the fourth day of NASA's 9th Robotic Mining Competition, May 17, inside the RobotPits at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Setup
2018-05-14
On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, team members from the Illinois Institute of Technology work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Setup
2018-05-14
On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, team members from the University of North Carolina at Charlotte work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Setup
2018-05-14
On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, team members from Temple University work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members and their faculty advisor, far left, from The University of North Carolina at Charlotte pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from the University of Colorado Boulder work on their robot miner in the RobotPits in the Educator Resource Center on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
First-time participants from the University of Maine, along with their faculty advisor, at far right, are with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
On the second day of NASA's 9th Robotic Mining Competition, May 15, team members from Saginaw Valley State University in Michigan work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
Team members and their advisor, far right, from Montana Tech of the University of Montana, prepare their robot miner on the second day of NASA's 9th Robotic Mining Competition, May 15, in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Surface texture of Vesta from optical polarimetry
NASA Technical Reports Server (NTRS)
Le Bertre, T.; Zellner, B.
1980-01-01
Polarimetric, photometric, and reflective spectroscopic properties of asteroid 4 Vesta are simulated in the laboratory by a preparation of eucrite Bereba consisting of a broad mixture of particle sizes (mainly greater than 50-micron) mixed and partially coated with particles of size 10 microns and less. Coarse grains are necessary for producing the same albedo and a very fine dust coating is necessary for producing the same polarization inversion angle as observed for Vesta. There are less small grains and fine dust in this sample than in lunar soils. Photometrically, if coating a sphere, this sample shows a constant brightness on the sunward half of the observed hemisphere, the brightness being given on the other half by the Minnaert reciprocity principle. With such a photometric behavior, the global geometric albedo and the sub-earth point geometric albedo differ by no more than 5%. The microscopic phase coefficient is 0.021 magnitude per degree for the sample; the larger value, 0.025, observed telescopically for Vesta, indicates that large-scale roughness is present on this asteroid.
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Twenty-Fourth Lunar and Planetary Science Conference. Part 2: G-M
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1993-01-01
The topics covered include the following: meteorites, meteoritic composition, geochemistry, planetary geology, planetary composition, planetary craters, the Moon, Mars, Venus, asteroids, planetary atmospheres, meteorite craters, space exploration, lunar geology, planetary surfaces, lunar surface, lunar rocks, lunar soil, planetary atmospheres, lunar atmosphere, lunar exploration, space missions, geomorphology, lithology, petrology, petrography, planetary evolution, Earth surface, planetary surfaces, volcanology, volcanos, lava, magma, mineralogy, minerals, ejecta, impact damage, meteoritic damage, tectonics, etc. Separate abstracts have been prepared for articles from this report.
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Of Death Stars and Death Rays: A Glimpse At The Future of Space Warfare
2013-04-01
remains in step. The potential for long-term energy mining from the moon (discussed later in this paper) must also be a consideration as there will be a...spacecraft to the Itokawa asteroid , collected soil samples, and safely returned the mission to Earth. 37 In 2007, they demonstrated their mastery...helium-3 is dispersed across the lunar surface, large-scale mining operations and specialized equipment needed to extract the gas from lunar rocks will
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Olff, H; Hoorens, B; de Goede, R G M; van der Putten, W H; Gleichman, J M
2000-10-01
We analyzed the dynamics of dominant plant species in a grazed grassland over 17 years, and investigated whether local shifts in these dominant species, leading to vegetation mosaics, could be attributed to interactions between plants and soil-borne pathogens. We found that Festuca rubra and Carex arenaria locally alternated in abundance, with different sites close together behaving out of phase, resulting in a shifting mosaic. The net effect of killing all soil biota on the growth of these two species was investigated in a greenhouse experiment using gamma radiation, controlling for possible effects of sterilization on soil chemistry. Both plant species showed a strong net positive response to soil sterilization, indicating that pathogens (e.g., nematodes, pathogenic fungi) outweighed the effect of mutualists (e.g., mycorrhizae). This positive growth response towards soil sterilization appeared not be due to effects of sterilization on soil chemistry. Growth of Carex was strongly reduced by soil-borne pathogens (86% reduction relative to its growth on sterilized soil) on soil from a site where this species decreased during the last decade (and Festuca increased), while it was reduced much less (50%) on soil from a nearby site where it increased in abundance during the last decade. Similarly, Festuca was reduced more (67%) on soil from the site where it decreased (and Carex increased) than on soil from the site where it increased (55%, the site where Carex decreased). Plant-feeding nematodes showed high small-scale variation in densities, and we related this variation to the observed growth reductions in both plant species. Carex growth on unsterilized soil was significantly more reduced at higher densities of plant-feeding nematodes, while the growth reduction in Festuca was independent of plant-feeding nematode densities. At high plant-feeding nematode densities, growth of Carex was reduced more than Festuca, while at low nematode densities the opposite was found. Each plant species thus seems to be affected by different (groups of) soil-borne pathogens. The resulting interaction web of plants and soil-borne pathogens is discussed. We hypothesize that soil disturbances by digging ants and rabbits may explain the small-scale variation in nematode densities, by locally providing "fresh" sand. We conclude that soil-borne pathogens may contribute to plant diversity and spatial mosaics of plants in grasslands.
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USDA-ARS?s Scientific Manuscript database
New peanut cultivars are available with very high yield potential and high levels of disease resistance. With rising input costs and shrinking return margins, all efforts must be made to harvest the full yield produced. Peanut crops are susceptible to high levels of pod loss during digging from a ...
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NASA Astrophysics Data System (ADS)
Kemper, K.; Throop, H.
2015-12-01
One of the greatest impacts on the global carbon cycle is changes in land use. Making this concept relevant and inquiry-based for high school students is challenging. Many are familiar with reconstructing paleo-climate from ice core data, but few have a connection to current climate research. Many students ask questions like 'What will our area be like in 20 years?' or 'How much does planting trees help?' while few have the scientific language to engage in a discussion to answer these questions. Our work connects students to climate change research in several ways: first, teacher Keska Kemper engaged in field research with Dr. Heather Throop creating a 'teacher in the field' perspective for students in the classroom. Dr. Throop met with Keska Kemper's students several times to develop an inquiry-based field study. Students predicted and then measured rates of respiration between different soil types in an urban park close to their school. Students then could compare their results from Portland, Oregon to Throop's work across a rain gradient in Australia. Discussions about percent tree cover and soil carbon helped students see connections between land use changes and changes in carbon cycling. Last, students examined satellite imagery to determine percent tree cover and numberss of trees to compare to soil carbon in the same region. Students were able to examine imagery over the last 30 years to visualize land use changes in the greater Portland area.
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NASA Astrophysics Data System (ADS)
He, Zhao; Lian, Pengfei; Song, Yan; Liu, Zhanjun; Song, Jinliang; Zhang, Junpeng; Feng, Jing; Yan, Xi; Guo, Quangui
2018-02-01
A densification process has been conducted on isostatic graphite (IG-110, TOYO TANSO CO., Ltd., Japan) by impregnating phenolic resin to get the densified isostatic graphite (D-IG-110) with pore diameter of nearly 11 nm specifically for molten salt reactor application. The microstructure, mechanical, thermophysical and other properties of graphite were systematically investigated and compared before and after the densification process. The molten fluoride salt and Xe135 penetration in the graphite were evaluated in a high-pressure reactor and a vacuum device, respectively. Results indicated that D-IG-110 exhibited improved properties including infiltration resistance to molten fluoride salt and Xe135 as compared to IG-110 due to its low porosity of 2.8%, the average pore diameter of 11 nm and even smaller open pores on the surface of the graphite. The fluoride salt infiltration amount of IG-110 was 13.5 wt% under 1.5 atm and tended to be saturated under 3 atm with the fluoride salt occupation of 14.8 wt%. As to the D-IG-110, no salts could be detected even up to 10 atm attempted loading. The helium diffusion coefficient of D-IG-110 was 6.92 × 10-8 cm2/s, significantly less than 1.21 × 10-2 cm2/s of IG-110. If these as-produced properties for impregnated D-IG-110 could be retained during MSR operation, the material could prove effective at inhibiting molten fluoride salt and Xe135 inventories in the graphite.
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Wang, Rui-Xiang; Yuan, Si-Tian; Liu, Jin-Biao; Wu, Jie; Qiu, Guanyinsheng
2018-06-06
A TBAB-mediated brominative 5-exo-dig oxy-cyclization of 2-alkynylbenzamide is described here for the synthesis of isobenzofuran-1-imines and isobenzofuran derivatives at room temperature with a high efficiency and a broad reaction scope. The resulting isobenzofuran derivatives are also applied for synthesising various substituted isobenzofuran derivatives.
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archAR: an archaeological augmented reality experience
NASA Astrophysics Data System (ADS)
Wiley, Bridgette; Schulze, Jürgen P.
2015-03-01
We present an application for Android phones or tablets called "archAR" that uses augmented reality as an alternative, portable way of viewing archaeological information from UCSD's Levantine Archaeology Laboratory. archAR provides a unique experience of flying through an archaeological dig site in the Levantine area and exploring the artifacts uncovered there. Using a Google Nexus tablet and Qualcomm's Vuforia API, we use an image target as a map and overlay a three-dimensional model of the dig site onto it, augmenting reality such that we are able to interact with the plotted artifacts. The user can physically move the Android device around the image target and see the dig site model from any perspective. The user can also move the device closer to the model in order to "zoom" into the view of a particular section of the model and its associated artifacts. This is especially useful, as the dig site model and the collection of artifacts are very detailed. The artifacts are plotted as points, colored by type. The user can touch the virtual points to trigger a popup information window that contains details of the artifact, such as photographs, material descriptions, and more.
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NASA Astrophysics Data System (ADS)
Gertsch, Richard E.
The earliest studies of asteroid mining proposed retrieving a main belt asteroid. Because of the very long travel times to the main asteroid belt, attention has shifted to the asteroids whose orbits bring them fairly close to the Earth. In these schemes, the asteroids would be bagged and then processed during the return trip, with the asteroid itself providing the reaction mass to propel the mission homeward. A mission to one of these near-Earth asteroids would be shorter, involve less weight, and require a somewhat lower change in velocity. Since these asteroids apparently contain a wide range of potentially useful materials, our study group considered only them. The topics covered include asteroid materials and properties, asteroid mission selection, manned versus automated missions, mining in zero gravity, and a conceptual mining method.
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NASA Technical Reports Server (NTRS)
Gertsch, Richard E.
1992-01-01
The earliest studies of asteroid mining proposed retrieving a main belt asteroid. Because of the very long travel times to the main asteroid belt, attention has shifted to the asteroids whose orbits bring them fairly close to the Earth. In these schemes, the asteroids would be bagged and then processed during the return trip, with the asteroid itself providing the reaction mass to propel the mission homeward. A mission to one of these near-Earth asteroids would be shorter, involve less weight, and require a somewhat lower change in velocity. Since these asteroids apparently contain a wide range of potentially useful materials, our study group considered only them. The topics covered include asteroid materials and properties, asteroid mission selection, manned versus automated missions, mining in zero gravity, and a conceptual mining method.
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Remote analysis of planetary soils: X-ray diffractometer development
NASA Technical Reports Server (NTRS)
Gregory, J. C.
1973-01-01
A system is described suitable for remote low power mineralogical analysis of lunar, planetary, or asteroid soils. It includes an X-ray diffractometer, fluorescence spectrometer, and sample preparation system. A one Curie Fe-55 source provides a monochromatic X-ray beam of 5.9 keV. Seeman-Bohlin or focusing geometry is employed in the camera, allowing peak detection to proceed simultaneously at all angles and obviating the need for moving parts. The detector system is an array of 500-600 proportional counters with a wire-spacing of 1 mm. An electronics unit comprising preamplifier, postamplifier, window discriminators, and storage flipflops requiring only 3.5 milliwatts was designed and tested. Total instrument power is less than 5 watts. Powder diffraction patterns using a flat breadboard multiwire counter were recorded.
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NASA Technical Reports Server (NTRS)
Noble, Sarah
2011-01-01
Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.
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Pore size distribution of a deeply excavated Oxisol after 19 years reclamation
NASA Astrophysics Data System (ADS)
dos Santos Batista Bonini, Carolina; de Cássia Marchini, Débora; Alves, Marlene Cristina; García de Arruda, Otton; Paz-Ferreiro, Jorge
2013-04-01
Digging of the local soil and using it as a raw material for construction purposes has been identified as a non-negligible source of land degradation. Techniques aimed at soil profile reconstruction and ecological restoration of soils truncated by mechanical excavation using heavy machinery have been investigated Both, total soil porosity and pore size distribution are important properties for soil management as well as for assessing the recovery of soil function after land degradation. In this way, macropores are responsible for aeration, whereas water storage depends on soil meso- and micropores in the soil and the optimal pore-size distribution is also an indicator of soil quality. We investigated the changes in the pore size distribution of a soil that was beheaded to extract raw materials after a 19 year period of reclamation, which involved the use of green manures, gypsum and pasture for the purpose of profile recovery. The studied area is located in Mato Grosso do Sul State, Brzil. A field trial was performed following a completely randomized experimental design with seven treatments and four replications. Starting 1992, the initial treatments were: 1) control (tilled bare soil), 2)Stizolobium aterrium, 3)Cajanus cajan, 4)lime+S. aterrimum, 5) lime+C. cajan, 6) lime + gypsum + S. aterrimum, 7) lime + gypsum+C. cajan. In 1994, all treatments with C. cajan were replaced by Canavalia ensiformis and in 1999, Brachiaria decumbens was implanted in all the experimental plots. Data from vegetated treatments were compared with bare soil (control) and native vegetation (Savannah). Soil samples were collected in 2011 at the 0.00-0.10, 0.10-0.20, and 0.20-0.40 m depths. Treatment differences were assessed by analysis of variance, following the Scott-Knott test (5%) of probability to compare averages. Macroporosity of the 0.00-0.10 m top layer was above the 0.10 m3m-3 threshold considered as critical for plant growth. On the 0.10-0.20 m layer only treatments with C. cajan later on followed by C. ensiformis reached macroporosities over the 0.10 m3m-3 threshold, and on the 0.20-0.40 m no treatment was above this critical value. In spite of the positive development of macroporosity in the restored soil profile, this physical attribute was far from the typical values corresponding to local soils under native Savannah vegetation.
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Clemente, Christofer J; Cooper, Christine E; Withers, Philip C; Freakley, Craig; Singh, Surya; Terrill, Philip
2016-10-15
The short-beaked echidna (Tachyglossus aculeatus) is a monotreme and therefore provides a unique combination of phylogenetic history, morphological differentiation and ecological specialisation for a mammal. The echidna has a unique appendicular skeleton, a highly specialised myrmecophagous lifestyle and a mode of locomotion that is neither typically mammalian nor reptilian, but has aspects of both lineages. We therefore were interested in the interactions of locomotor biomechanics, ecology and movements for wild, free-living short-beaked echidnas. To assess locomotion in its complex natural environment, we attached both GPS and accelerometer loggers to the back of echidnas in both spring and summer. We found that the locomotor biomechanics of echidnas is unique, with lower stride length and stride frequency than reported for similar-sized mammals. Speed modulation is primarily accomplished through changes in stride frequency, with a mean of 1.39 Hz and a maximum of 2.31 Hz. Daily activity period was linked to ambient air temperature, which restricted daytime activity during the hotter summer months. Echidnas had longer activity periods and longer digging bouts in spring compared with summer. In summer, echidnas had higher walking speeds than in spring, perhaps because of the shorter time suitable for activity. Echidnas spent, on average, 12% of their time digging, which indicates their potential to excavate up to 204 m 3 of soil a year. This information highlights the important contribution towards ecosystem health, via bioturbation, of this widespread Australian monotreme. © 2016. Published by The Company of Biologists Ltd.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-24
..., 5 cores, 2 digging stick handles, 2 flake perforators, 2 hafted drills, 1 piece of incised bone, 7 pestles, 2 projectile points, and 1 fragment of worked bone. The 32 lots of objects are 4 lots of animal... worked bone fragment, 1 bottle fragment, 13 bullet cartridges, 3 copper pendants, 6 cores, 1 digging...
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Denning behaviour of non-gravid wolves, Canis lupus
Mech, L.D.; Phillips, M.K.; Smith, D.W.; Kreeger, T.J.
1996-01-01
Wild wolves (Canis lupus) that had produced pups in earlier years but were not currently pregnant, and ovariectomized captive wolves, dug dens during and after the whelping season even though they produced no pups. These observations suggest that den digging is not a function of pregnancy or of ovarian estrogen or progesterone. We hypothesize that increasing prolactin in spring elicits or mediates den-digging behavior.
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1974-12-01
defect types were tested at various levels: Comet- Tail, Dig-Nick, Dirt Brinell, Grind-Skip Lines, Impingement, Orange Peel , Pit, Scratch and "Liney...Shallow irregular indentation of surface. <.0015 max. dim. -(<.0008)*’ Otange Peel Pebbly appearance of raceway surface. Small ** Comet Tail Pit...scratch; dig-nick; impingement; grind-skip lines; and orange peel . The data obtained indicated that these defects in most cases, affected bearing
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NASA Astrophysics Data System (ADS)
Gerriets, A.; von Lom-Keil, H.; Spiess, V.; Zwanzig, C.; Bruns, R.
2003-04-01
The combination of the ATLAS PARASOUND sediment echosounder, designed by ATLAS Hydrographic, and the digital recording software package ParaDigMA (commercially available as ATLAS PARASTORE-3) for online digitisation, preprocessing and visualisation of recorded seismograms has proven to be a reliable system for high-resolution acoustic sea floor studies. During 10 years of successful operation aboard several research vessels, including R/V Meteor, R/V Sonne and R/V Polarstern, the system has been only slightly modified. Based on this experience, today's PARASOUND/ParaDigMA system has accomplished the step from DOS towards Windows platform and network capability. In cooperation of ATLAS Hydrographic and the Department of Earth Sciences, University of Bremen a major upgrade of the PARASOUND/ParaDigMA system has been developed that adds significant functionality for surveys of sediment structures and sea floor morphology. The innovations primarily concern the control section of the ATLAS PARASOUND echosounder and the ParaDigMA user front end. The previous analogue PARASOUND control terminal has been replaced by a small real time control PC responsible for the control of the echosounder as well as for the continuous digitisation of the data. The control PC communicates via standard network protocols metadata and data with client applications that can display and store the acquired data on different computers on the network. The new network capabilities of the system overcome former limitations and admit a high flexibility with respect to numbers and locations of operator and recording/display PCs. The system now offers a simultaneous parallel registration of the 2.5-5.5kHz parametric signal and the 18kHz NBS signal. This feature in combination with the recording of complete soundings including the entire water column provides the basis for evolving scientific research topics e. g. gas venting. The ParaDigMA recording software now operates on Windows platforms which provide sophisticated possibilities in data visualisation as well as improved methods in data handling. Former approved features as online plot of the preprocessed seismograms have been continued.
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New Perspectives on the Dynamical State of Extraplanar Diffuse Ionized Gas Layers
NASA Astrophysics Data System (ADS)
Boettcher, Erin; Zweibel, Ellen; Gallagher, John S.; Benjamin, Robert A.
2018-01-01
Gaseous, disk-halo interfaces are an important boundary in the baryon cycle in galaxies like the Milky Way, and their structure, support, and kinematics carry clues about the star formation feedback and accretion processes that produce them. Due to their unexpectedly large scale heights, which are often several times greater than their thermal scale heights, it is unclear whether they are in dynamical equilibrium, or are evidence of a galactic fountain, wind, or accretion flow. In the nearby, edge-on disk galaxies NGC 891 and NGC 5775, we test a dynamical equilibrium model of the extraplanar diffuse ionized gas (eDIG) layer by quantifying the thermal, turbulent, magnetic field, and cosmic ray pressure gradients using optical emission-line spectroscopy from the SparsePak IFU at the WIYN Observatory and the Robert Stobie Spectrograph on the Southern African Large Telescope and radio continuum observations from Continuum Halos in Nearby Galaxies - an EVLA Survey. The vertical pressure gradients are too shallow to produce the observed scale heights at the moderate galactocentric radii where the gas is believed to be found (R < 8 kpc). For the low-inclination galaxy M83, we develop a Markov Chain Monte Carlo method to decompose the [NII]λλ6548, 6583, Hα, and [SII]λλ6717, 6731 emission lines into multiple components, and identify eDIG emission based on its rotational velocity lag and elevated [NII]/Hα and [SII]/Hα line ratios. The median, line-of-sight velocity dispersion of the eDIG layer, σ = 96 km/s, greatly exceeds the horizontal velocity dispersions observed in edge-on eDIG layers (σ = 20 - 60 km/s), presenting the possibility that these layers have anisotropic random motions. The role of an anisotropic velocity dispersion in producing eDIG scale heights, as well as the absence of evidence for large-scale inflow or outflow, motivates further study of eDIG dynamics in face-on galaxies with a range of star formation rates. This work was supported by the NSF GRFP under Grant No. DGE-1256259.
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Asteroid mass estimation using Markov-chain Monte Carlo
NASA Astrophysics Data System (ADS)
Siltala, Lauri; Granvik, Mikael
2017-11-01
Estimates for asteroid masses are based on their gravitational perturbations on the orbits of other objects such as Mars, spacecraft, or other asteroids and/or their satellites. In the case of asteroid-asteroid perturbations, this leads to an inverse problem in at least 13 dimensions where the aim is to derive the mass of the perturbing asteroid(s) and six orbital elements for both the perturbing asteroid(s) and the test asteroid(s) based on astrometric observations. We have developed and implemented three different mass estimation algorithms utilizing asteroid-asteroid perturbations: the very rough 'marching' approximation, in which the asteroids' orbital elements are not fitted, thereby reducing the problem to a one-dimensional estimation of the mass, an implementation of the Nelder-Mead simplex method, and most significantly, a Markov-chain Monte Carlo (MCMC) approach. We describe each of these algorithms with particular focus on the MCMC algorithm, and present example results using both synthetic and real data. Our results agree with the published mass estimates, but suggest that the published uncertainties may be misleading as a consequence of using linearized mass-estimation methods. Finally, we discuss remaining challenges with the algorithms as well as future plans.
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NASA Astrophysics Data System (ADS)
An, Meiyan; Wang, Zhaokui; Zhang, Yulin
2017-01-01
The self-organizing control strategy for asteroid intelligent detection swarm, which is considered as a space application instance of intelligent swarm, is developed. The leader-follower model for the asteroid intelligent detection swarm is established, and the further analysis is conducted for massive asteroid and small asteroid. For a massive asteroid, the leader spacecraft flies under the gravity field of the asteroid. For a small asteroid, the asteroid gravity is negligible, and a trajectory planning method is proposed based on elliptic cavity virtual potential field. The self-organizing control strategy for the follower spacecraft is developed based on a mechanism of velocity planning and velocity tracking. The simulation results show that the self-organizing control strategy is valid for both massive asteroid and small asteroid, and the exploration swarm forms a stable configuration.
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NASA Technical Reports Server (NTRS)
Marcus, Matthew; Sloane, Joshua; Ortiz, Oliver; Barbee, Brent
2015-01-01
BILLIARDS Baseline Instrumented Lithology Lander, Inspector, and Asteroid Redirection Demonstration System Proposed demonstration mission for Billiard-Ball concept Select asteroid pair with natural close approach to minimize cost and complexity Primary Objectives Rendezvous with a small (10m), near Earth (alpha) asteroid Maneuver the alpha asteroid to a collision with a 100m (beta) asteroid Produce a detectable deflection or disruption of the beta asteroid Secondary objectives Contribute knowledge of asteroid composition and characteristics Contribute knowledge of small-body formation Opportunity for international collaboration
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NASA Technical Reports Server (NTRS)
Warren, Paul H.; Kallemeyn, Gregory W.
1992-01-01
A new model of the production of the uniformly low plagioclase and Al contents of ureilites is proposed. It is argued that those contents are consequences of widespread explosive volcanism during the evolution of the parent asteroid(s). It is noted that the great abundance of graphite on the ureilite asteroid(s) made them ideal sites for explosive volcanism driven by oxidation of graphite in partial melts ascending within the asteroid(s).
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NASA Technical Reports Server (NTRS)
Matson, D. L.
1988-01-01
The purpose of this task is to support asteroid research and the operation of an Asteroid Team within the Earth and Space Sciences Division at the Jet Propulsion Laboratory (JPL). The Asteroid Team carries out original research on asteroids in order to discover, better characterize and define asteroid properties. This information is needed for the planning and design of NASA asteroid flyby and rendezvous missions. The asteroid Team also provides scientific and technical advice to NASA and JPL on asteroid related programs. Work on asteroid classification continued and the discovery of two Earth-approaching M asteroids was published. In the asteroid photometry program researchers obtained N or Q photometry for more than 50 asteroids, including the two M-earth-crossers. Compositional analysis of infrared spectra (0.8 to 2.6 micrometer) of asteroids is continuing. Over the next year the work on asteroid classification and composition will continue with the analysis of the 60 reduced infrared spectra which we now have at hand. The radiometry program will continue with the reduction of the N and Q bandpass data for the 57 asteroids in order to obtain albedos and diameters. This year the emphasis will shift to IRAS follow-up observations; which includes objects not observed by IRAS and objects with poor or peculiar IRAS data. As in previous year, we plan to give top priority to any opportunities for observing near-Earth asteroids and the support (through radiometric lightcurve observations from the IRTF) of any stellar occultations by asteroids for which occultation observation expeditions are fielded. Support of preparing of IRAS data for publication and of D. Matson for his participation in the NASA Planetary Astronomy Management and Operations Working Group will continue.
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NASA Astrophysics Data System (ADS)
Windham-Myers, L.; Holmquist, J. R.; Sundquist, E. T.; Drexler, J. Z.; Bliss, N.
2016-12-01
Wetland soils have long been recognized as conditional archives of past environments, including vegetation structure, nutrient status, sediment supply and the variability in those factors. Both sedimentary processes and organic accretion processes form the soil matrix that identifies wetland soils as "hydric" while also providing archival insights. As repositories of information on net biogeochemical processes, their down-core and across-site structure can show both consistency and distinction. Through several related studies, we have been exploring the use of component-level U.S. Natural Resources Conservation Service (NRCS) Soil Survey data (SSURGO) to map carbon density to 1m depth across wetlands of the US, with an emphasis on coastal wetlands. To assess the accuracy of mapped carbon data from SSURGO, several field-generated datasets (public or compiled for the NASA-funded Blue Carbon Monitoring Project) have been extracted for key metrics such as dry bulk density (g/cc), organic carbon content (%C by combustion) and the combination, soil carbon density (g C /cc) with depth. These profiles indicate ecogeomorphic feedbacks of elevation, vegetation structure and biogeochemical processes through millennia, illustrating both resilience and shifts in behavior that constrain wetland extent as well as wetland function. National datasets such as SSURGO and validation datasets such as the EPA's National Wetland Condition Assessment (NWCA) and Louisiana's Coastwide Reference Monitoring System (CRMS) are publically available and have been underutilized for predicting and/or validating changes in wetland carbon dynamics. We have explored their use for interpretating and understanding changing carbon accretion rates, changing wetland extents through elevation gain or loss, and changing methane emissions. This talk will focus on insights for wetland carbon sequestration functions as determined by soil core structure, both for coastal settings and potentially for inland wetlands as well.
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Modelling soil carbon fate under erosion process in vineyard
NASA Astrophysics Data System (ADS)
Novara, Agata; Scalenghe, Riccardo; Minacapilli, Mario; Maltese, Antonino; Capodici, Fulvio; Borgogno Mondino, Enrico; Gristina, Luciano
2017-04-01
Soil erosion processes in vineyards beyond water runoff and sediment transport have a strong effect on soil organic carbon loss (SOC) and redistribution along the slope. The variation of SOC across the landscape determines a difference in soil fertility and vine productivity. The aim of this research was to study erosion of a Mediterranean vineyard, develop an approach to estimate the SOC loss, correlate the vines vigor with sediment and carbon erosion. The study was carried out in a Sicilian (Italy) vineyard, planted in 2011. Along the slope, six pedons were studied by digging 6 pits up to 60cm depth. Soil was sampled in each pedon every 10cm and SOC was analyzed. Soil erosion, detachment and deposition areas were measured by pole height method. The vigor of vegetation was expressed in term of NDVI (Normalized difference Vegetation Index) derived from a satellite image (RapidEye) acquired at berry pre-veraison stage (July) and characterized by 5 spectral bands in the shortwave region, including a band in the red wavelength (R, 630-685 nm) and in the near infrared (NIR, 760-850 nm) . Results showed that soil erosion, sediments redistribution and SOC across the hill was strongly affected by topographic features, slope and curvature. The erosion rate was 46Mg ha-1 y-1 during the first 6 years since planting. The SOC redistribution was strongly correlated with the detachment or deposition area as highlighted by pole height measurements. The approach developed to estimate the SOC loss showed that during the whole study period the off-farm SOC amounts to 1.6Mg C ha-1. As highlighted by NDVI results, the plant vigor is strong correlated with SOC content and therefore, developing an accurate NDVI approach could be useful to detect the vineyard areas characterized by low fertility due to erosion process.
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Worm Grunting, Fiddling, and Charming—Humans Unknowingly Mimic a Predator to Harvest Bait
Catania, Kenneth C.
2008-01-01
Background For generations many families in and around Florida's Apalachicola National Forest have supported themselves by collecting the large endemic earthworms (Diplocardia mississippiensis). This is accomplished by vibrating a wooden stake driven into the soil, a practice called “worm grunting”. In response to the vibrations, worms emerge to the surface where thousands can be gathered in a few hours. Why do these earthworms suddenly exit their burrows in response to vibrations, exposing themselves to predation? Principal Findings Here it is shown that a population of eastern American moles (Scalopus aquaticus) inhabits the area where worms are collected and that earthworms have a pronounced escape response from moles consisting of rapidly exiting their burrows to flee across the soil surface. Recordings of vibrations generated by bait collectors and moles suggest that “worm grunters” unknowingly mimic digging moles. An alternative possibility, that worms interpret vibrations as rain and surface to avoid drowning is not supported. Conclusions Previous investigations have revealed that both wood turtles and herring gulls vibrate the ground to elicit earthworm escapes, indicating that a range of predators may exploit the predator-prey relationship between earthworms and moles. In addition to revealing a novel escape response that may be widespread among soil fauna, the results show that humans have played the role of “rare predators” in exploiting the consequences of a sensory arms race. PMID:18852902
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International Asteroid Mission (IAM)
NASA Astrophysics Data System (ADS)
Yamaguchi, Ryuuji
1991-07-01
International Asteroid Mission (IAM) is a program aimed at developing resources of asteroids abundantly existing near the earth. This report describes the research results of design project of the International Space University (ISU) held in 1990 at Tront-York University. ISU research and asteroid survey results, and the manned asteroid mining mission are outlined. Classification of asteroids existing near the earth and asteroid resource processing and use analyses are conducted. Asteroid selection flow charts are introduced, and the 1982HR-Orpheus is selected as a candidate asteroid because it takes an approaching orbit toward the earth, requires small delta V, and possesses abundant carbonaceous chondrites. Characteristics of 1982HR-Orpheus are presented. Mission requirements, mission outlines, transportation systems, and mining and processing systems for manned asteroid mining missions are presented.
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Perret, Pascale; Slimani, Lotfi; Briat, Arnaud; Villemain, Danièle; Halimi, Serge; Demongeot, Jacques; Fagret, Daniel; Ghezzi, Catherine
2007-05-01
Insulin resistance, characterised by an insulin-stimulated glucose transport defect, is an important feature of the pre-diabetic state that has been observed in numerous pathological disorders. The purpose of this study was to assess variations in glucose transport in rats using (125)I-6-deoxy-6-iodo-D-glucose (6DIG), a new tracer of glucose transport proposed as an imaging tool to assess insulin resistance in vivo. Two protocols were performed, a hyperinsulinaemic-euglycaemic clamp and a normoinsulinaemic-normoglycaemic protocol, in awake control and insulin-resistant fructose-fed rats. The tracer was injected at steady state, and activity in 11 tissues and the blood was assessed ex vivo at several time points. A multicompartmental mathematical model was developed to obtain fractional transfer coefficients of 6DIG from the blood to the organs. Insulin sensitivity of fructose-fed rats, estimated by the glucose infusion rate, was reduced by 40% compared with control rats. At steady state, 6DIG uptake was significantly stimulated by insulin in insulin-sensitive tissues of control rats (basal versus insulin: diaphragm, p < 0.01; muscle, p<0.05; heart, p<0.001), whereas insulin did not stimulate 6DIG uptake in insulin-resistant fructose-fed rats. Moreover, in these tissues, the fractional transfer coefficients of entrance were significantly increased with insulin in control rats (basal vs insulin: diaphragm, p<0.001; muscle, p<0.001; heart, p<0.01) whereas no significant changes were observed in fructose-fed rats. This study sets the stage for the future use of 6DIG as a non-invasive means for the evaluation of insulin resistance by nuclear imaging.
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Bottorff, Joan L; Oliffe, John L; Sarbit, Gayl; Caperchione, Cristina; Clark, Marianne; Anand, Anima; Howay, Kym
2017-03-01
Evidence related to the effects of tobacco exposure in pregnancy and on infant and child health have focused on women's smoking cessation. Less often addressed is men's smoking, which when continued in fatherhood, reduces the chances of female partners' cessation and can negatively impact children's health as well as men's health. Dads in Gear (DIG) is an innovative program designed specifically for new fathers who want to reduce and quit smoking that includes three components: smoking cessation, fathering, and physical activity. The over-arching purpose of this study is to evaluate the feasibility of the DIG program and provide estimates of program efficacy. The purpose of this article is to describe the rationale and protocol for evaluating the DIG program's feasibility, acceptability and potential effectiveness. Using a prospective, non-comparative design, the DIG program will be implemented and evaluated in six communities. The program will be offered by trained facilitators to fathers who currently smoke and want to quit. The RE-AIM framework will guide the evaluation. Open-ended questions in participant surveys, and semi-structured interviews and weekly telephone de-briefs with facilitators will provide data for a process evaluation. Estimates of effectiveness include smoking behavior, fathering and physical activity measures at baseline, end of program, and 3-month follow up. The DIG program could support positive changes with respect to smoking cessation, physical activity and overall health for men. These effects could also promote family health. The program might also provide an effective model for engaging men in other health behavior change. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
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Validating Variational Bayes Linear Regression Method With Multi-Central Datasets.
Murata, Hiroshi; Zangwill, Linda M; Fujino, Yuri; Matsuura, Masato; Miki, Atsuya; Hirasawa, Kazunori; Tanito, Masaki; Mizoue, Shiro; Mori, Kazuhiko; Suzuki, Katsuyoshi; Yamashita, Takehiro; Kashiwagi, Kenji; Shoji, Nobuyuki; Asaoka, Ryo
2018-04-01
To validate the prediction accuracy of variational Bayes linear regression (VBLR) with two datasets external to the training dataset. The training dataset consisted of 7268 eyes of 4278 subjects from the University of Tokyo Hospital. The Japanese Archive of Multicentral Databases in Glaucoma (JAMDIG) dataset consisted of 271 eyes of 177 patients, and the Diagnostic Innovations in Glaucoma Study (DIGS) dataset includes 248 eyes of 173 patients, which were used for validation. Prediction accuracy was compared between the VBLR and ordinary least squared linear regression (OLSLR). First, OLSLR and VBLR were carried out using total deviation (TD) values at each of the 52 test points from the second to fourth visual fields (VFs) (VF2-4) to 2nd to 10th VF (VF2-10) of each patient in JAMDIG and DIGS datasets, and the TD values of the 11th VF test were predicted every time. The predictive accuracy of each method was compared through the root mean squared error (RMSE) statistic. OLSLR RMSEs with the JAMDIG and DIGS datasets were between 31 and 4.3 dB, and between 19.5 and 3.9 dB. On the other hand, VBLR RMSEs with JAMDIG and DIGS datasets were between 5.0 and 3.7, and between 4.6 and 3.6 dB. There was statistically significant difference between VBLR and OLSLR for both datasets at every series (VF2-4 to VF2-10) (P < 0.01 for all tests). However, there was no statistically significant difference in VBLR RMSEs between JAMDIG and DIGS datasets at any series of VFs (VF2-2 to VF2-10) (P > 0.05). VBLR outperformed OLSLR to predict future VF progression, and the VBLR has a potential to be a helpful tool at clinical settings.
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Perret, Pascale; Slimani, Lotfi; Briat, Arnaud; Villemain, Danièle; Halimi, Serge; Demongeot, Jacques; Fagret, Daniel; Ghezzi, Catherine
2007-01-01
Purpose Insulin resistance, characterised by an insulin-stimulated glucose transport defect, is an important feature of the pre-diabetic state and it has been observed in numerous pathological disorders. The purpose of this study was to assess variations in glucose transport in rats with 125I-6-Deoxy-6-Iodo-D-glucose (6DIG), a new tracer of glucose transport proposed as an imaging tool to assess insulin resistance in vivo. Methods Two protocols were performed, a hyperinsulinaemic-euglycaemic clamp and a normoinsulinaemic normoglycaemic protocol, in awake control and insulin-resistant fructose-fed rats. The tracer was injected at steady state, and activity in 11 tissues and the blood were assessed ex vivo at several time points. A multicompartmental mathematical model was developed to obtain fractional transfer coefficients of 6DIG from the blood to the organs. Results Insulin sensitivity of fructose-fed rats, estimated by the glucose infusion rate, was reduced by 40% compared with control rats. At steady-state, 6DIG uptake was significantly stimulated by insulin in insulin-sensitive tissues of control rats (basal versus insulin: diaphragm, p<0.01; muscle, p<0.05; heart, p<0.001), whereas insulin did not stimulate 6DIG uptake in insulin-resistant fructose-fed rats. Moreover, in these tissues, the fractional transfer coefficients of entrance were significantly increased with insulin in control rats (basal vs insulin: diaphragm, p<0.001; muscle, p<0.001; heart, p<0.01) and whereas no significant changes were observed in fructose-fed rats. Conclusion This study sets the stage for the future use of 6DIG as a non-invasive means for the evaluation of insulin resistance by nuclear imaging. PMID:17171359
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A chlorhexidine-loaded biodegradable cellulosic device for periodontal pockets treatment.
Tabary, Nicolas; Chai, Feng; Blanchemain, Nicolas; Neut, Christel; Pauchet, Lucile; Bertini, Sabrina; Delcourt-Debruyne, Elisabeth; Hildebrand, Hartmut Frederic; Martel, Bernard
2014-01-01
Absorbent points widely used in endodontic therapy were transformed into bioresorbable chlorhexidine delivery systems for the treatment of the periodontal pocket by preventing its recolonization by the subgingival microflora. These paper points (PPs) were first oxidized to promote their resorption, then grafted with β-cyclodextrin (CD) or maltodextrin (MD) in order to achieve sustained delivery of chlorhexidine. We investigated the oxidation step parameters through the time of reaction and the nitric and phosphoric acid ratios in the oxidizing mixture, and then the dextrin grafting step parameters through the time and temperature of reaction. A first selection of the appropriate functionalization parameters was undertaken in relation to the degradation profile kinetics of the oxidized (PPO) and oxidized-grafted samples (PPO-CD and PPO-MD). Samples were then loaded with chlorhexidine digluconate (digCHX), a widely used antiseptic agent in periodontal therapy. The release kinetics of digCHX from PPO-CD and PPO-MD samples were compared to PP, PPO and to PerioChip(®) (a commercial digCHX containing gelatine chip) in phosphate buffered saline (pH 7.4) by ultraviolet spectrophotometry. The cytocompatibility of the oxidized-grafted PP was demonstrated by cell proliferation assays. Finally, the disc diffusion test from digCHX loaded PPO-MD samples immersed in human plasma was developed on pre-inoculated agar plates with four common periodontal pathogenic strains: Fusobacterium nucleatum, Prevotella melaninogenica, Aggregatibacter actinomycetem comitans and Porphyromonas gingivalis. To conclude, the optimized oxidized-dextrin-grafted PPs responded to our initial specifications in terms of resorption and digCHX release rates and therefore could be adopted as a reliable complementary periodontal therapy. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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Solo dwarfs I: survey introduction and first results for the Sagittarius dwarf irregular galaxy
NASA Astrophysics Data System (ADS)
Higgs, C. R.; McConnachie, A. W.; Irwin, M.; Bate, N. F.; Lewis, G. F.; Walker, M. G.; Côté, P.; Venn, K.; Battaglia, G.
2016-05-01
We introduce the Solitary Local dwarfs survey (Solo), a wide-field photometric study targeting every isolated dwarf galaxy within 3 Mpc of the Milky Way. Solo is based on (u)gi multiband imaging from Canada-France-Hawaii Telescope/MegaCam for northern targets, and Magellan/Megacam for southern targets. All galaxies fainter than MV ≃ -18 situated beyond the nominal virial radius of the Milky Way and M31 (≳300 kpc) are included in this volume-limited sample, for a total of 42 targets. In addition to reviewing the survey goals and strategy, we present results for the Sagittarius dwarf irregular galaxy (Sag DIG), one of the most isolated, low-mass galaxies, located at the edge of the Local Group. We analyse its resolved stellar populations and their spatial distributions. We provide updated estimates of its central surface brightness and integrated luminosity, and trace its surface brightness profile to a level fainter than 30 mag arcsec-2. Sag DIG is well described by a highly elliptical (disc-like) system following a single component Sérsic model. However, a low-level distortion is present at the outer edges of the galaxy that, were Sag DIG not so isolated, would likely be attributed to some kind of previous tidal interaction. Further, we find evidence of an extremely low level, extended distribution of stars beyond ˜5 arcmin (>1.5 kpc) that suggests Sag DIG may be embedded in a very low-density stellar halo. We compare the stellar and H I structures of Sag DIG, and discuss results for this galaxy in relation to other isolated, dwarf irregular galaxies in the Local Group.
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NASA Astrophysics Data System (ADS)
Sanders, Ryan L.; Shapley, Alice E.; Zhang, Kai; Yan, Renbin
2017-12-01
Galaxy metallicity scaling relations provide a powerful tool for understanding galaxy evolution, but obtaining unbiased global galaxy gas-phase oxygen abundances requires proper treatment of the various line-emitting sources within spectroscopic apertures. We present a model framework that treats galaxies as ensembles of H II and diffuse ionized gas (DIG) regions of varying metallicities. These models are based upon empirical relations between line ratios and electron temperature for H II regions, and DIG strong-line ratio relations from SDSS-IV MaNGA IFU data. Flux-weighting effects and DIG contamination can significantly affect properties inferred from global galaxy spectra, biasing metallicity estimates by more than 0.3 dex in some cases. We use observationally motivated inputs to construct a model matched to typical local star-forming galaxies, and quantify the biases in strong-line ratios, electron temperatures, and direct-method metallicities as inferred from global galaxy spectra relative to the median values of the H II region distributions in each galaxy. We also provide a generalized set of models that can be applied to individual galaxies or galaxy samples in atypical regions of parameter space. We use these models to correct for the effects of flux-weighting and DIG contamination in the local direct-method mass-metallicity and fundamental metallicity relations, and in the mass-metallicity relation based on strong-line metallicities. Future photoionization models of galaxy line emission need to include DIG emission and represent galaxies as ensembles of emitting regions with varying metallicity, instead of as single H II regions with effective properties, in order to obtain unbiased estimates of key underlying physical properties.
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2012-05-23
CAPE CANAVERAL, Fla. - At NASA’s Kennedy Space Center Visitor Complex in Florida, Lunabotics presentation judges gather on stage during the opening ceremony for NASA’s Lunabotics Mining Competition. From left, are Lead Presentation Judge Kristina Brink with Kennedy’s Education Office, Chuck Sahm with Caterpillar, Inc., Creg Raffington with Kennedy’s Engineering and Technology Directorate, and Kevin Miller with Kennedy’s Center Operations Directorate. The mining competition is sponsored by NASA Kennedy Space Center’s Education Office for the agency’s Exploration Systems Mission Directorate. Undergraduate and graduate students from more than 50 universities and colleges in the U.S. and other countries use their remote-controlled Lunabots to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to lunar soil. For more information, visit www.nasa.gov/lunabotics. Photo credit: NASA/Frankie Martin
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Robotic Mining Competition - Media Day
2017-05-25
NASA Kennedy Space Center Director Bob Cabana, at right, talks with Kurt Leucht, event emcee, during media day at the agency's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. At the mining arena, Cabana shared his thoughts about the competition and the progress made to make Kennedy a multi-user spaceport. Teams from colleges and universities around the U.S. used their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition Awards Ceremony
2017-05-26
Inside the Apollo-Saturn V Center at the Kennedy Space Center Visitor Complex in Florida, team members from the University of North Carolina at Charlotte receive third-place in the Caterpillar Autonomy Award during the award ceremony for NASA's 8th Annual Robotic Mining Competition. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26, at the visitor complex. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Debris Kicked Up By Impact of A Protective Cover from Viking Lander 1
1996-12-12
The patch of dark material toward the top of this picture (arrow) taken by NASA's Viking 1 Lander is the debris kicked up by the impact of a protective cover ejected from the spacecraft at 1 a.m. today. The cylindrical cover, which bounced out of view of the camera, protects the scoop at the end of the soil sampler arm. (The scoop will dig into the Martian surface for the first time on July 28). Dust and debris atop the footpad remains as it was seen in the Lander's first picture taken immediately after landing two days ago. No wind modification is apparent. On the surface, a variety of block sizes, shapes and tones are seen, and some rocks are Partially buried. http://photojournal.jpl.nasa.gov/catalog/PIA00384
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Cock, Matthew J. W.; Allard, Gillian B.
2013-01-01
The authors made two visits to the Juba Sugar Project in south-west Somalia, at the beginning of the minor rains in October 1986, and at the beginning of the main rains in March 1987. Observations were made on morphospecies of scarabaeid white grub larvae, the adults, and the two associated for the key economic species, Cochliotis melolonthoides and Brachylepis werneri. Sampling larvae and adults by digging soil quadrats and adults by light trapping gave useful information on their biology and phenology. Sampling methods were evaluated and economic thresholds were extrapolated based on earlier work. Natural enemies were surveyed, and entomopathogenic nematodes and a cordyceps fungus (Ophiocordyceps barnesii) were considered to have potential to be used as biological control interventions. PMID:26464389
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Cock, Matthew J W; Allard, Gillian B
2013-06-18
The authors made two visits to the Juba Sugar Project in south-west Somalia, at the beginning of the minor rains in October 1986, and at the beginning of the main rains in March 1987. Observations were made on morphospecies of scarabaeid white grub larvae, the adults, and the two associated for the key economic species, Cochliotis melolonthoides and Brachylepis werneri. Sampling larvae and adults by digging soil quadrats and adults by light trapping gave useful information on their biology and phenology. Sampling methods were evaluated and economic thresholds were extrapolated based on earlier work. Natural enemies were surveyed, and entomopathogenic nematodes and a cordyceps fungus (Ophiocordyceps barnesii) were considered to have potential to be used as biological control interventions.
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2014-05-19
CAPE CANAVERAL, Fla. – Students from Oakton Community College in Illinois prepare their robot for NASA’s Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Ben Smegelsky
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2014-05-20
CAPE CANAVERAL, Fla. – College and university teams prepare their robots for NASA’s Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Ben Smegelsky
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2014-05-20
CAPE CANAVERAL, Fla. – A college team prepares its robot for a trial run at NASA’s Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Ben Smegelsky
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2014-05-19
CAPE CANAVERAL, Fla. – College students prepare their robot for NASA’s Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Ben Smegelsky
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Robotic Mining Competition Awards Ceremony
2017-05-26
Team Astrobotics from The University of Alabama won the top award, the Joe Kosmo Award for Excellence, and several other awards, during NASA's 8th Annual Robotic Competition award ceremony inside the Apollo-Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. used their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participated in other competition requirements, May 22-26, at the visitor complex. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
On the second day of NASA's 9th Robotic Mining Competition, May 15, team members from the South Dakota School of Mines & Engineering work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. Second from right is Kennedy Space Center Director Bob Cabana. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Opening Ceremony
2018-05-15
On the second day of NASA's 9th Robotic Mining Competition, May 15, team members from Mississippi State University work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. At far right is Kennedy Space Center Director Bob Cabana. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Activities
2018-05-17
Team members from the University of Arkansas make adjustments to their robot miner for its turn in the mining arena on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. They are in the RobotPits inside the Educator Resource Center. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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NASA Astrophysics Data System (ADS)
Wawra, Anna; Friesl-Hanl, Wolfgang; Watzinger, Andrea; Soja, Gerhard; Puschenreiter, Markus
2016-04-01
Conventional remediation techniques like "dig and dump" are costly and limited in scale. Plant- and microbe-based alternatives, e.g. phytoremediation options, offer a cheap and environmentally friendly approach that can be applied on larger areas. However, the application of phytoremediation techniques to co-contaminated sites may be hindered due to a potential inhibition of biodegradation processes by the presence of heavy metals in soil. Therefore, the objective of this study is to test the hypothesis that the degradation of organic pollutants can be enhanced by immobilising potentially toxic heavy metals. This study aims to identify the influence of heavy metal immobilisation on the degradation of organic pollutants, and to determine chemical, physical and biological measures further accelerating these processes. The influence of heavy metals on organic pollutant degradation dynamics is assessed using 13C-phospholipid fatty acid analysis (13C-PLFA). Application of 13C-labeled phenanthrene allows the identification of microbial groups responsible for the degradation process. For metal immobilisation and enhanced biodegradation, distinct mineral and organic soil amendments (iron oxides, gravel sludge, biochar) are deployed, partly in combination with fast-growing and pollution-tolerant woody plants (willow, black locust and alder). Results of an incubation batch experiment show a fast degradation of the phenanthrene label within the first two weeks by various microbial groups (gram negative bacteria as indicated by the cy17:0 peak) resulting in a decrease by up to 80% of the total PAH concentration (Σ 16 EPA PAHs) measured in soil. A similar trend was observed in the greenhouse pot experiment, whereby heavy metal accumulation in the woody plants growing on the co-contaminated soil significantly varied with plant species (willow > black locust, alder).
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Veh, R W
1991-01-02
For double tracing experiments, wheat germ agglutinin (WGA) molecules labeled with two different haptens are desirable. In the present report the suitability of digoxigenylated WGA (DIG-WGA) for retrograde tracing was investigated. For this purpose the new tracer was pressure injected into rat brains and the transported DIG-WGA visualized via its digoxigenyl group with an alkaline phosphatase linked anti DIG antibody in permanently stained sections of high quality. With fixatives containing 2.5% glutaraldehyde only few positive cells were found. However, at milder fixation conditions (4% paraformaldehyde, 0.05% glutaraldehyde 0.2% picric acid, 30 min) retrogradely labeled cells were detected with a sensitivity comparable to tetramethylbenzidine protocols for conventional WGA-HRP (horseradish peroxidase) tracing. Preliminary experiments suggest excellent suitability for double labeling.
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ERIC Educational Resources Information Center
Shook, Melissa; Webster, Jeff; Fletcher, Carla
2010-01-01
In 2006, TG estimated that 47,000 bachelor's degrees would be lost in Texas due to financial barriers experienced by college-qualified high school graduates from the class of 2004. With more current data, TG now estimates that the number will be 52,800. "Digging Deeper" explores how students who enroll in college continue to experience…
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Photoionized Mixing Layer Models of the Diffuse Ionized Gas
NASA Astrophysics Data System (ADS)
Binette, Luc; Flores-Fajardo, Nahiely; Raga, Alejandro C.; Drissen, Laurent; Morisset, Christophe
2009-04-01
It is generally believed that O stars, confined near the galactic midplane, are somehow able to photoionize a significant fraction of what is termed the "diffuse ionized gas" (DIG) of spiral galaxies, which can extend up to 1-2 kpc above the galactic midplane. The heating of the DIG remains poorly understood, however, as simple photoionization models do not reproduce the observed line ratio correlations well or the DIG temperature. We present turbulent mixing layer (TML) models in which warm photoionized condensations are immersed in a hot supersonic wind. Turbulent dissipation and mixing generate an intermediate region where the gas is accelerated, heated, and mixed. The emission spectrum of such layers is compared with observations of Rand of the DIG in the edge-on spiral NGC 891. We generate two sequence of models that fit the line ratio correlations between [S II]/Hα, [O I]/Hα, [N II]/[S II], and [O III]/Hβ reasonably well. In one sequence of models, the hot wind velocity increases, while in the other, the ionization parameter and layer opacity increase. Despite the success of the mixing layer models, the overall efficiency in reprocessing the stellar UV is much too low, much less than 1%, which compels us to reject the TML model in its present form.
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Radiative transfer calculations of the diffuse ionized gas in disc galaxies with cosmic ray feedback
NASA Astrophysics Data System (ADS)
Vandenbroucke, Bert; Wood, Kenneth; Girichidis, Philipp; Hill, Alex S.; Peters, Thomas
2018-05-01
The large vertical scale heights of the diffuse ionized gas (DIG) in disc galaxies are challenging to model, as hydrodynamical models including only thermal feedback seem to be unable to support gas at these heights. In this paper, we use a three-dimensional Monte Carlo radiation transfer code to post-process disc simulations of the Simulating the Life-Cycle of Molecular Clouds project that include feedback by cosmic rays. We show that the more extended discs in simulations including cosmic ray feedback naturally lead to larger scale heights for the DIG which are more in line with observed scale heights. We also show that including a fiducial cosmic ray heating term in our model can help to increase the temperature as a function of disc scale height, but fails to reproduce observed DIG nitrogen and sulphur forbidden line intensities. We show that, to reproduce these line emissions, we require a heating mechanism that affects gas over a larger density range than is achieved by cosmic ray heating, which can be achieved by fine tuning the total luminosity of ionizing sources to get an appropriate ionizing spectrum as a function of scale height. This result sheds a new light on the relation between forbidden line emissions and temperature profiles for realistic DIG gas distributions.
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Alabugin, Igor V; Timokhin, Vitaliy I; Abrams, Jason N; Manoharan, Mariappan; Abrams, Rachel; Ghiviriga, Ion
2008-08-20
Despite being predicted to be stereoelectronically favorable by the Baldwin rules, efficient formation of a C-C bond through a 5-endo-dig radical cyclization remained unknown for more than 40 years. This work reports a remarkable increase in the efficiency of this process upon beta-Ts substitution, which led to the development of an expedient approach to densely functionalized cyclic 1,3-dienes. Good qualitative agreement between the increased efficiency and stereoselectivity for the 5-endo-dig cyclization of Ts-substituted vinyl radicals and the results of density functional theory analysis further confirms the utility of computational methods in the design of new radical processes. Although reactions of Br atoms generated through photochemical Ts-Br bond homolysis lead to the formation of cyclic dibromide side products, the yields of target bromosulfones in the photochemically induced reactions can be increased by recycling the dibromide byproduct into the target bromosulfones through a sequence of addition/elimination reactions at the exocyclic double bond. Discovery of a relatively efficient radical 5-endo-dig closure, accompanied by a C-C bond formation, provides further support to stereoelectronic considerations at the heart of the Baldwin rules and fills one of the last remaining gaps in the arsenal of radical cyclizations.
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Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu
2016-01-01
Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams. PMID:27063002
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Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu
2016-04-11
Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca(2+)/Mg(2+)-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.
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Photodegradation of selected organics on Mars
NASA Astrophysics Data System (ADS)
ten Kate, I. L.; Boosman, A.; Fornaro, T.; King, H. E.; Kopacz, K. A.; Wolthers, M.
2017-09-01
At least as much as 2.4 million kg of unaltered organic material is estimated to be delivered to the Martian surface each year. However, intense UV irradiation and the highly oxidizing and acidic nature of Martian soil cause degradation of organic compounds. Here we present first results obtained with the recently developed PALLAS facility at Utrecht University. This facility is specifically designed to simulate planetary and asteroid surface conditions to study the photocatalytic properties of relevant planetary minerals. Our results tentatively show degradation of several compounds and preservation of others.
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Phoenix Mars Lander with Solar Arrays Open
NASA Technical Reports Server (NTRS)
2006-01-01
NASA's next Mars-bound spacecraft, the Phoenix Mars Lander, was partway through assembly and testing at Lockheed Martin Space Systems, Denver, in September 2006, progressing toward an August 2007 launch from Florida. In this photograph, spacecraft specialists work on the lander after its fan-like circular solar arrays have been spread open for testing. The arrays will be in this configuration when the spacecraft is active on the surface of Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. It will dig into the surface, test scooped-up samples for carbon-bearing compounds and serve as NASA's first exploration of a potential modern habitat on Mars. The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena. -
Phoenix Mars Lander in Testing
NASA Technical Reports Server (NTRS)
2006-01-01
NASA's next Mars-bound spacecraft, the Phoenix Mars Lander, was partway through assembly and testing at Lockheed Martin Space Systems, Denver, in September 2006, progressing toward an August 2007 launch from Florida. In this photograph, spacecraft specialists work on the lander after its fan-like circular solar arrays have been spread open for testing. The arrays will be in this configuration when the spacecraft is active on the surface of Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. It will dig into the surface, test scooped-up samples for carbon-bearing compounds and serve as NASA's first exploration of a potential modern habitat on Mars. -
2014-05-23
CAPE CANAVERAL, Fla. -- Kennedy Space Center engineer Marc Seibert presents the Communication Award to the University of New Hampshire team members during NASA's 2014 Robotic Mining Competition award ceremony inside the Space Shuttle Atlantis attraction at the Kennedy Space Center Visitor Complex in Florida. The team moved 10 kilograms of simulated Martian soil with its robot while using the least amount of communication power. More than 35 teams from colleges and universities around the U.S. designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. The competition includes on-site mining, writing a systems engineering paper, performing outreach projects for K-12 students, slide presentation and demonstrations, and team spirit. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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NASA Astrophysics Data System (ADS)
van Mourik, Jan; Vera, Hein; Wallinga, Jakob
2013-04-01
The landscape in extensive areas in SE-Netherlands is underlain by coversand, deposited during the Late Glacial of the Weichselian. In the Preboreal, aeolian processes reduced soil formation. From the Preboreal to the Atlantic a deciduous climax forest developed. The geomorphology was a coversand landscape, composed of ridges (umbric podzols), coversand plains (gleyic podzols), coversand depressions (histic podzols) and small valleys (gleysols). The area was used by hunting people during the Late Paleolithic and Mesolithic. During the Bronze and Iron Ages the area was populated by people, living from forest grazing, shifting cultivation and trade. The natural deciduous forest gradually degraded into Calluna heath. The deforestation accelerated the soil acidification and affected the hydrology, which is reflected in drying out of ridges and wetting of depressions, promoting the development of histic podzols and even histosols. Aeolian erosion was during this period restricted to local, small scale sand drifting, related to natural hazards as forest fires and hurricanes and shifting cultivation. Sustainable crop productivity on chemically poor sandy substrates required application of organic fertilizers, composed of a mixture of organic litter and animal manure with a very low mineral compound, produced in shallow stables. At least since 1000 AD, heath management was regulated by a series of rules that aimed to protect the valuable heat lands against degradation. During the 11th, 12th and 13th centuries there was an increasing demand for wood and clear cutting transformed the majority of the forests in driftsand landscapes. The most important market was formed by the very wealthy Flemish cities. The exposed soil surface was subjected to wind erosion and sand drifting which endangered the Calluna heath, arable land and even farmhouses. As a consequence, umbric podzols, the natural climax soil under deciduous forests on coversand, degraded into larger scale driftsand landscapes, characterized by deflation plains (gleyic arenosols) and complexes of inland dunes (haplic arenosols). Clear cutting was responsible for the mediaeval first large scale expansion of drift sand landscapes. In such driftsand landscapes, the majority of the podzolic soils in coversand has been truncated by aeolian erosion. Only on scattered sheltered sites in the landscape, palaeopodzols were buried under mono or polycyclic driftsand deposits. They are now the valuable soil archives for palaeoecological research. During the 18th century, the population growth and regional economic activity stimulated the agricultural productivity. Farmers introduced the innovative 'deep stable' technique to increase the production of fertilizers. Farmers started sod digging, including the top of the Ah horizon of the humus forms. This consequently promoted heath degradation and sand drifting, resulting in the extension of driftsand landscapes. Deep stable economy and sod digging was responsible for the 18th century second large scale expansion of drift sand landscapes. During the 19th century, farmers tried to find alternative fertilizers and authorities initiated reforestation projects. The invention of chemical fertilizers at the end of the 19th century marked the end of the period of heath management and plaggic agriculture. The heath was no longer used for the harvesting of plaggic matter and new land management practices were introduced. Heath was reclaimed to new arable land or reforested with Scotch pine. Geomorphological features as inland dunes and plaggic covers survived in the landscape and are now included in the geological inheritance.
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NASA Astrophysics Data System (ADS)
Vovides, Alejandra G.; Marín-Castro, Beatriz; Barradas, Guadalupe; Berger, Uta; López-Portillo, Jorge
2016-12-01
This work presents the development of a low-cost method to measure the length cable roots of black mangrove (Avicennia germinans) trees to define the boundaries of central part of the anchoring root system (CPRS) without the need to fully expose root systems. The method was tested to locate and measure the length shallow woody root systems. An ultrasonic Doppler fetal monitor (UD) and a stock of steel rods (SR) were used to probe root locations without removing sediments from the surface, measure their length and estimate root-soil plate dimensions. The method was validated by comparing measurements with root lengths taken through direct measurement of excavated cable roots and from root-soil plate radii (exposed root-soil material when a tree tips over) of five up-rooted trees with stem diameters (D130) ranging between 10 and 50 cm. The mean CPRS radius estimated with the use of the Doppler was directly correlated with tree stem diameter and was not significantly different from the root-soil plate mean radius measured from up-rooted trees or from CPRS approximated by digging trenches. Our method proved to be effective and reliable in following cable roots for large amounts of trees of both black and white mangrove trees. In a period of 40 days of work, three people were capable of measuring 648 roots belonging to 81 trees, out of which 37% were found grafted to other tree roots. This simple method can be helpful in following shallow root systems with minimal impact and help map root connection networks of grafted trees.
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NASA Astrophysics Data System (ADS)
van Mourik, Jan; Doorenbosch, Marieke
2016-04-01
The evolution of heath lands during the Holocene has been registered in various soil records . Paleoecological analyses of these records enable to reconstruct the changing economic and cultural management of heaths and the consequences for landscape and soils. Heaths are characteristic components of cultural landscape mosaics on sandy soils in the Netherlands. The natural habitat of heather species was moorland. At first, natural events like forest fires and storms caused small-scale forest degradation, in addition on the forest degradation accelerated due to cultural activities like forest grazing, wood cutting and shifting cultivation. Heather plants invaded on degraded forest soils and heaths developed. People learned to use the heaths for economic and cultural purposes. The impact of the heath management on landscape and soils was registered in soil records of barrows, drift sand sequences and plaggic Anthrosols. Based on pollen diagrams of such records we could reconstruct that heaths were developed and used for cattle grazing before the Bronze Age. During the Late Neolithic, the Bronze Age and Iron Age, people created the barrow landscape on the ancestral heaths. After the Iron Age people probably continued with cattle grazing on the heaths and plaggic agriculture until the Early Middle Ages. After 1000 AD two events affected the heaths. At first deforestation for the sale of wood resulted in the first regional extension of sand drifting and heath degradation. After that the introduction of the deep stable economy and heath sods digging resulted in acceleration of the rise of plaggic horizons, severe heath degradation and the second extension of sand drifting. At the end of the 19th century the heath lost its economic value due to the introduction of chemical fertilizers. The heaths were transformed into 'new' arable fields and forests and due to deep ploughing most soil archives were destroyed. Since 1980 AD, the remaining relicts of the ancestral heaths are preserved and restored in the frame of the programs to improve the regional and national geo-biodiversity.
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The Asteroid Impact Mission - Deflection Demonstration (AIM - D2)
NASA Astrophysics Data System (ADS)
Küppers, M.; Michel, P.; Carnelli, I.
2017-09-01
The Asteroid Impact Mission (AIM) is ESA's contribution to the international Asteroid Impact Deflection Assessment (AIDA) cooperation, targeting the demonstration of deflection of a hazardous near-earth asteroid. AIM will also be the first in-depth investigation of a binary asteroid and make measurements that are relevant for the preparation of asteroid resource utilisation. AIM is foreseen to rendezvous with the binary near-Earth asteroid (65803) Didymos and to observe the system before, during, and after the impact of NASA's Double Asteroid Redirection Test (DART) spacecraft. Here we describe the observations to be done by the simplified version Asteroid Impact Mission - Deflection Demonstration (AIM-D2) and show that most of the original AIM objectives can still be achieved.
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Proceedings of the 38th Lunar and Planetary Science Conference
NASA Technical Reports Server (NTRS)
2007-01-01
The sessions in the conference include: Titan, Mars Volcanism, Mars Polar Layered Deposits, Early Solar System Isotopes, SPECIAL SESSION: Mars Reconnaissance Orbiter: New Ways of Studying the Red Planet, Achondrites: Exploring Oxygen Isotopes and Parent-Body Processes, Solar System Formation and Evolution, SPECIAL SESSION: SMART-1, . Impact Cratering: Observations and Experiments, SPECIAL SESSION: Volcanism and Tectonism on Saturnian Satellites, Solar Nebula Composition, Mars Fluvial Geomorphology, Asteroid Observations: Spectra, Mostly, Mars Sediments and Geochemistry: View from the Surface, Mars Tectonics and Crustal Dichotomy, Stardust: Wild-2 Revealed, Impact Cratering from Observations and Interpretations, Mars Sediments and Geochemistry: The Map View, Chondrules and Their Formation, Enceladus, Asteroids and Deep Impact: Structure, Dynamics, and Experiments, Mars Surface Process and Evolution, Martian Meteorites: Nakhlites, Experiments, and the Great Shergottite Age Debate, Stardust: Mainly Mineralogy, Astrobiology, Wind-Surface Interactions on Mars and Earth, Icy Satellite Surfaces, Venus, Lunar Remote Sensing, Space Weathering, and Impact Effects, Interplanetary Dust/Genesis, Mars Cratering: Counts and Catastrophes?, Chondrites: Secondary Processes, Mars Sediments and Geochemistry: Atmosphere, Soils, Brines, and Minerals, Lunar Interior and Differentiation, Mars Magnetics and Atmosphere: Core to Ionosphere, Metal-rich Chondrites, Organics in Chondrites, Lunar Impacts and Meteorites, Presolar/Solar Grains, Topics for Print Only papers are: Outer Planets/Satellites, Early Solar System, Interplanetary Dust, Comets and Kuiper Belt Objects, Asteroids and Meteoroids, Chondrites, Achondrites, Meteorite Related, Mars Reconnaissance Orbiter, Mars, Astrobiology, Planetary Differentiation, Impacts, Mercury, Lunar Samples and Modeling, Venus, Missions and Instruments, Global Warming, Education and Public Outreach, Poster sessions are: Asteroids/Kuiper Belt Objects, Galilean Satellites: Geology and Mapping, Titan, Volcanism and Tectonism on Saturnian Satellites, Early Solar System, Achondrite Hodgepodge, Ordinary Chondrites, Carbonaceous Chondrites, Impact Cratering from Observations and Interpretations, Impact Cratering from Experiments and Modeling, SMART-1, Planetary Differentiation, Mars Geology, Mars Volcanism, Mars Tectonics, Mars: Polar, Glacial, and Near-Surface Ice, Mars Valley Networks, Mars Gullies, Mars Outflow Channels, Mars Sediments and Geochemistry: Spirit and Opportunity, Mars Reconnaissance Orbiter: New Ways of Studying the Red Planet, Mars Reconnaissance Orbiter: Geology, Layers, and Landforms, Oh, My!, Mars Reconnaissance Orbiter: Viewing Mars Through Multicolored Glasses; Mars Science Laboratory, Phoenix, and ExoMars: Science, Instruments, and Landing Sites; Planetary Analogs: Chemical and Mineral, Planetary Analogs: Physical, Planetary Analogs: Operations, Future Mission Concepts, Planetary Data, Imaging, and Cartography, Outer Solar System, Presolar/Solar Grains, Stardust Mission; Interplanetary Dust, Genesis, Asteroids and Comets: Models, Dynamics, and Experiments, Venus, Mercury, Laboratory Instruments, Methods, and Techniques to Support Planetary Exploration; Instruments, Techniques, and Enabling Techologies for Planetary Exploration; Lunar Missions and Instruments, Living and Working on the Moon, Meteoroid Impacts on the Moon, Lunar Remote Sensing, Lunar Samples and Experiments, Lunar Atmosphere, Moon: Soils, Poles, and Volatiles, Lunar Topography and Geophysics, Lunar Meteorites, Chondrites: Secondary Processes, Chondrites, Martian Meteorites, Mars Cratering, Mars Surface Processes and Evolution, Mars Sediments and Geochemistry: Regolith, Spectroscopy, and Imaging, Mars Sediments and Geochemistry: Analogs and Mineralogy, Mars: Magnetics and Atmosphere, Mars Aeolian Geomorphology, Mars Data Processing and Analyses, Astrobiology, Engaging Student Educators and the Public in Planetary Science,
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Project RAMA: Reconstructing Asteroids Into Mechanical Automata
NASA Technical Reports Server (NTRS)
Dunn, Jason; Fagin, Max; Snyder, Michael; Joyce, Eric
2017-01-01
Many interesting ideas have been conceived for building space-based infrastructure in cislunar space. From O'Neill's space colonies, to solar power satellite farms, and even prospecting retrieved near earth asteroids. In all the scenarios, one thing remained fixed - the need for space resources at the outpost. To satisfy this need, O'Neill suggested an electromagnetic railgun to deliver resources from the lunar surface, while NASA's Asteroid Redirect Mission called for a solar electric tug to deliver asteroid materials from interplanetary space. At Made In Space, we propose an entirely new concept. One which is scalable, cost effective, and ensures that the abundant material wealth of the inner solar system becomes readily available to humankind in a nearly automated fashion. We propose the RAMA architecture, which turns asteroids into self-contained spacecraft capable of moving themselves back to cislunar space. The RAMA architecture is just as capable of transporting conventional-sized asteroids on the 10-meter length scale as transporting asteroids 100 meters or larger, making it the most versatile asteroid retrieval architecture in terms of retrieved-mass capability. This report describes the results of the Phase I study funded by the NASA NIAC program for Made In Space to establish the concept feasibility of using space manufacturing to convert asteroids into autonomous, mechanical spacecraft. Project RAMA, Reconstituting Asteroids into Mechanical Automata, is designed to leverage the future advances of additive manufacturing (AM), in-situ resource utilization (ISRU) and in-situ manufacturing (ISM) to realize enormous efficiencies in repeated asteroid redirect missions. A team of engineers at Made In Space performed the study work with consultation from the asteroid mining industry, academia, and NASA. Previous studies for asteroid retrieval have been constrained to studying only asteroids that are both large enough to be discovered, and small enough to be captured and transported using Earth-launched propulsion technology. Project RAMA is not forced into this constraint. The mission concept studied involved transporting a much larger approximately 50-meter asteroid to cislunar space. Demonstration of transport of a 50-meter-class asteroid has several ground-breaking advantages. First, the returned material is of an industrial, rather than just scientific, quantity (greater than 10,000 tonnes versus approximately10s of tonnes). Second, the "useless" material in the asteroid is gathered and expended as part of the asteroid's propulsion system, allowing the returned asteroid to be considerably "purer" than a conventional asteroid retrieval mission. Third, the infrastructure used to convert and return the asteroid is reusable, and capable of continually returning asteroids to cislunar space.
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NASA Astrophysics Data System (ADS)
Rossi, Alessandro; Jacobson, S.; Marzari, F.; Scheeres, D.; Davis, D. R.
2013-10-01
From the results of a comprehensive asteroid population evolution model, we conclude that the YORP-induced rotational fission hypothesis has strong repercussions for the small size end of the Main Belt asteroid size frequency distribution. These results are consistent with observed asteroid population statistics. The foundation of this model is the asteroid rotation model of Marzari et al. (2011), which incorporates both the YORP effect and collisional evolution. This work adds to that model the rotational fission hypothesis (i.e. when the rotation rate exceeds a critical value, erosion and binary formation occur). The YORP effect timescale for large asteroids with diameters D > ~6 km is longer than the collision timescale in the Main Belt, thus the frequency of large asteroids is determined by a collisional equilibrium (e.g. Bottke 2005), but for small asteroids with diameters D < ~6 km, the asteroid population evolution model confirms that YORP-induced rotational fission destroys small asteroids more frequently than collisions. Therefore, the frequency of these small asteroids is determined by an equilibrium between the creation of new asteroids out of the impact debris of larger asteroids and the destruction of these asteroids by YORP-induced rotational fission. By introducing a new source of destruction that varies strongly with size, YORP-induced rotational fission alters the slope of the size frequency distribution. Using the outputs of the asteroid population evolution model and a 1-D collision evolution model, we can generate this new size frequency distribution and it matches the change in slope observed by the SKADS survey (Gladman 2009). This agreement is achieved with both an accretional power-law or a truncated “Asteroids were Born Big” size frequency distribution (Weidenschilling 2010, Morbidelli 2009).
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Near-Earth Asteroid Returned Sample (NEARS)
NASA Technical Reports Server (NTRS)
Shoemaker, Eugene M.; Cheng, Andrew F.
1994-01-01
The concept of the Near-Earth Asteroid Returned Sample (NEARS) mission is to return to Earth 10-100 g from each of four to six sites on a near-Earth asteroid and to perform global characterization of the asteroid and measure mass, volume, and density to ten percent. The target asteroid for the mission is 4660 Nereus, probably a primitive C-type asteroid, with the alternate target being 1989ML, an extremely accessible asteroid of unknown type. Launch dates will be 1998, 2000, 2002, and 2004 on the Delta II-7925 launch vehicle. The mission objectives are three-fold. (1) Provide first direct and detailed petrological, chemical, age, and isotopic characterization of a near-Earth asteroid and relate it to terrestrial, lunar, and meteoritic materials. (2) Sample the asteroid regolith and characterize any exotic fragments. (3) Identify heterogeneity in the asteroid's isotopic properties, age, and elemental chemistry.
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Asteroid size distributions for the main belt and for asteroid families
NASA Astrophysics Data System (ADS)
Kazantzev, A.; Kazantzeva, L.
2017-12-01
The asteroid-size distribution for he Eos family was constructed. The WISE database containing the albedo p and the size D of over 80,000 asteroids was used. The b parameter of the power-law dependence has a minimum at some average values of the asteroid size of the family. A similar dependence b(D) exists for the whole asteroid belt. An assumption on the possible similarity of the formation mechanisms of the asteroid belt as a whole and separate families is made.
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Teaching Soil Science in Primary and Secondary Schools
NASA Technical Reports Server (NTRS)
Levine, Elissa R.
1998-01-01
Earth's thin layer of soil is a fragile resource, made up of minerals, organic materials, air, water, and billions of living organisms. Soils plays a variety of critical roles that sustain life on Earth. If we think about soil, we tend to see it first as the source of most of the food we eat and the fibers we use, such as wood and cotton. Few students realize that soils also provide the key ingredients to many of the medicines (including antibiotics), cosmetics, and dyes that we use. Fewer still understand the importance of soils in integrating, controlling, and regulating the movement of air, water, materials, and energy between the hydrosphere, lithosphere, atmosphere, and biosphere. Because soil sustains life, it offers both a context and a natural laboratory for investigating these interactions. The enclosed poster, which integrates soil profiles with typical landscapes in which soils form, can also help students explore the interrelationships of Earth systems and gain an understanding of our soil resources. The poster, produced jointly by the American Geological Institute and the Soil Science Society of America, aims to increase awareness of the importance of soil, as does the GLOBE (Global Learning and Observations To Benefit the Environment) Program. Vice President Al Gore instituted the GLOBE Program on Earth Day of 1993 to increase environmental awareness of individuals throughout the world, contribute to a better scientific understanding of the Earth, and help all students reach higher levels of achievement in science and mathematics. GLOBE functions as a partnership between scientists, students, and teachers in which scientists design protocols for specific measurements they need for their research that can be performed by K-12 students. Teachers are trained in the GLOBE protocols and teach them to their students. Students make the measurements, enter data via the Internet to a central data archive, and the data becomes available to scientists and the general community. Students benefit by having a "hands-on"experience in science, math, and technology, using their local environment as a learning laboratory, as well as contact with scientists and other students around the world. Soil investigations have become an essential component of GLOBE. The protocols that have been developed so far within the GLOBE program include GPS Location, Atmosphere/Climate, Soil Characterization, Soil Moisture and Temperature, Land Cover/Biometry, Hydrology, and Satellite Image Classification. For the GLOBE Soil Characterization Protocol, students explore the physical. chemical, and morphological properties of the soil at their study site. They are asked to dig a pit or use an auger to about 1 meter at at least 2 sites.
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Dictionary of Basic Military Terms
1965-04-01
having nuclear charges. 101 ATOMNAYA SILOVAYA (ENERGEHCHESKAYA) KORA- BEL’NAYA (SUDOVAYA) USTANOVKA (atomic power plant for ship propulsion )- A special...atomic power plant for ship propulsion consists of an atomic "boiler," or reactor, a turbine (steam or gas), and electro- mechanical machinery. The...type, is mounted on a heay artillery tractor chassis. A high - speed trench-digging machine can dig trenches to a depth of 1.5 meters. The machine’s
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Ionization of the diffuse gas in galaxies: Hot low-mass evolved stars at work
NASA Astrophysics Data System (ADS)
Flores-Fajardo, N.; Morisset, C.; Stasinska, G.; Binette, L.
2011-10-01
The Diffuse Ionized Medium (DIG) is visible through its faint optical line emission outside classical HII regions (Reynolds 1971) and turns out to be a major component of the interstellar medium in galaxies. OB stars in galaxies likely represent the main source of ionizing photons for the DIG. However, an additional source is needed to explain the increase of [NII]/Hα, [SII]/Hα with galactic height.
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Scratch and dig analysis for Metis mirrors surfaces defects evaluation
NASA Astrophysics Data System (ADS)
Špína, M.; Procháska, F.; Melich, R.
2016-11-01
The presented paper aims to theoretically analyze the possibilities, advantages and drawbacks of standard methods used for the assessment of optical surface defects (the so-called Scratch and Dig analysis). Based on the acquired knowledge, we design and apply a process of SaD analysis suitable for the evaluation of optical surfaces of mirrors of the space coronagraph Metis, whose manufacturing was successfully implemented within the Centre Toptec in the past period.
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Edge-on View of Near-Earth Asteroids
2012-05-16
NEOWISE, the asteroid-hunting portion of NASA WISE mission, illustrates the differences between orbits of a typical near-Earth asteroid blue and a potentially hazardous asteroid, or PHA orange. PHAs are a subset of the near-Earth asteroids NEAs.
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Small bodies and the outer planets and Appendices 1 and 2
NASA Technical Reports Server (NTRS)
Davis, D. R.
1974-01-01
Correlations of asteroid spectral reflectivity characteristics with orbital parameters have been sought. Asteroid proper elements and extreme heliocentric distance were examined. Only general trends were noted, primarily red asteroids and asteroids with IR (.95 micron) absorption bands are concentrated toward the inner part of the belt. Also, asteroids with the pyroxene band tend to have larger proper eccentricities relative to non-banded asteroids.
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NASA Astrophysics Data System (ADS)
Jacobson, S.; Scheeres, D.; Rossi, A.; Marzari, F.; Davis, D.
2014-07-01
From the results of a comprehensive asteroid-population-evolution model, we conclude that the YORP-induced rotational-fission hypothesis has strong repercussions for the small size end of the main-belt asteroid size-frequency distribution and is consistent with observed asteroid-population statistics and with the observed sub-populations of binary asteroids, asteroid pairs and contact binaries. The foundation of this model is the asteroid-rotation model of Marzari et al. (2011) and Rossi et al. (2009), which incorporates both the YORP effect and collisional evolution. This work adds to that model the rotational fission hypothesis (i.e. when the rotation rate exceeds a critical value, erosion and binary formation occur; Scheeres 2007) and binary-asteroid evolution (Jacobson & Scheeres, 2011). The YORP-effect timescale for large asteroids with diameters D > ˜ 6 km is longer than the collision timescale in the main belt, thus the frequency of large asteroids is determined by a collisional equilibrium (e.g. Bottke 2005), but for small asteroids with diameters D < ˜ 6 km, the asteroid-population evolution model confirms that YORP-induced rotational fission destroys small asteroids more frequently than collisions. Therefore, the frequency of these small asteroids is determined by an equilibrium between the creation of new asteroids out of the impact debris of larger asteroids and the destruction of these asteroids by YORP-induced rotational fission. By introducing a new source of destruction that varies strongly with size, YORP-induced rotational fission alters the slope of the size-frequency distribution. Using the outputs of the asteroid-population evolution model and a 1-D collision evolution model, we can generate this new size-frequency distribution and it matches the change in slope observed by the SKADS survey (Gladman 2009). This agreement is achieved with both an accretional power-law or a truncated ''Asteroids were Born Big'' size-frequency distribution (Weidenschilling 2010, Morbidelli 2009). The binary-asteroid evolution model is highly constrained by the modeling done in Jacobson & Scheeres, and therefore the asteroid-population evolution model has only two significant free parameters: the ratio of low-to-high-mass-ratio binaries formed after rotational fission events and the mean strength of the binary YORP (BYORP) effect. Using this model, we successfully reproduce the observed small-asteroid sub-populations, which orthogonally constrain the two free parameters. We find the outcome of rotational fission most likely produces an initial mass-ratio fraction that is four to eight times as likely to produce high-mass-ratio systems as low-mass-ratio systems, which is consistent with rotational fission creating binary systems in a flat distribution with respect to mass ratio. We also find that the mean of the log-normal BYORP coefficient distribution B ≈ 10^{-2}.
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Mission options for rendezvous with the most accessible Near-Earth Asteroid - 1989 ML
NASA Technical Reports Server (NTRS)
Mcadams, Jim V.
1992-01-01
The recent discovery of the Amor-class 1989 ML, the most accessible known asteroid for minimum-energy rendezvous missions, has expedited the search for frequent, low-cost Near-Earth Asteroid rendezvous and round-trip missions. This paper identifies trajectory characteristics and assesses mass performance for low Delta V ballistic rendezvous opportunities to 1989 ML during the period 1996-2010. This asteroid also offers occasional unique extended mission opportunities, such as the lowest known Delta V requirement for any asteroid sample return mission as well as pre-rendezvous asteroid flyby and post-rendezvous comet flyby opportunities requiring less than 5.25 km/sec total Delta V. This paper also briefly comments concerning mission opportunities for asteroid 1991 JW, which recently replaced other known asteroids as the most accessible Near-Earth Asteroid for fast rendezvous and round-trip missions.
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Digging the New York City Skyline: Soil Fungal Communities in Green Roofs and City Parks
McGuire, Krista L.; Payne, Sara G.; Palmer, Matthew I.; Gillikin, Caitlyn M.; Keefe, Dominique; Kim, Su Jin; Gedallovich, Seren M.; Discenza, Julia; Rangamannar, Ramya; Koshner, Jennifer A.; Massmann, Audrey L.; Orazi, Giulia; Essene, Adam; Leff, Jonathan W.; Fierer, Noah
2013-01-01
In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg) compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs. PMID:23469260
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Digging the New York City Skyline: soil fungal communities in green roofs and city parks.
McGuire, Krista L; Payne, Sara G; Palmer, Matthew I; Gillikin, Caitlyn M; Keefe, Dominique; Kim, Su Jin; Gedallovich, Seren M; Discenza, Julia; Rangamannar, Ramya; Koshner, Jennifer A; Massmann, Audrey L; Orazi, Giulia; Essene, Adam; Leff, Jonathan W; Fierer, Noah
2013-01-01
In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg) compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs.
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Speckle interferometry of asteroids
NASA Technical Reports Server (NTRS)
Drummond, Jack
1988-01-01
This final report for NASA Contract NAGw-867 consists of abstracts of the first three papers in a series of four appearing in Icarus that were funded by the preceding contract NAGw-224: (1) Speckle Interferometry of Asteroids I. 433 Eros; (2) Speckle Interferometry of Asteroids II. 532 Herculina; (3) Speckle Interferometry of Asteroids III. 511 Davida and its Photometry; and the fourth abstract attributed to NAGw-867, (4) Speckle Interferometry of Asteroids IV. Reconstructed images of 4 Vesta; and a review of the results from the asteroid interferometry program at Steward Observatory prepared for the Asteroids II book, (5) Speckle Interferometry of Asteroids. Two papers on asteroids, indirectly related to speckle interferometry, were written in part under NAGw-867. One is in press and its abstract is included here: Photometric Geodesy of Main-Belt Asteroids. II. Analysis of Lightcurves for Poles, Periods and Shapes; and the other paper, Triaxial Ellipsoid Dimensions and Rotational Pole of 2 Pallas from Two Stellar Occultations, is included in full.
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Asteroid mass estimation using Markov-Chain Monte Carlo techniques
NASA Astrophysics Data System (ADS)
Siltala, Lauri; Granvik, Mikael
2016-10-01
Estimates for asteroid masses are based on their gravitational perturbations on the orbits of other objects such as Mars, spacecraft, or other asteroids and/or their satellites. In the case of asteroid-asteroid perturbations, this leads to a 13-dimensional inverse problem where the aim is to derive the mass of the perturbing asteroid and six orbital elements for both the perturbing asteroid and the test asteroid using astrometric observations. We have developed and implemented three different mass estimation algorithms utilizing asteroid-asteroid perturbations into the OpenOrb asteroid-orbit-computation software: the very rough 'marching' approximation, in which the asteroid orbits are fixed at a given epoch, reducing the problem to a one-dimensional estimation of the mass, an implementation of the Nelder-Mead simplex method, and most significantly, a Markov-Chain Monte Carlo (MCMC) approach. We will introduce each of these algorithms with particular focus on the MCMC algorithm, and present example results for both synthetic and real data. Our results agree with the published mass estimates, but suggest that the published uncertainties may be misleading as a consequence of using linearized mass-estimation methods. Finally, we discuss remaining challenges with the algorithms as well as future plans, particularly in connection with ESA's Gaia mission.
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2005-12-01
requirements are met by metabolizing grazed vegetation. Prairie dogs dig burrows to an average depth of 2-3 meters with some tunnels interconnecting with...the potential to impact non- target species such as mice, kangaroo rats, and some songbirds. Establishing control zones at CAFB and MAFR could not be...Gutierrezia sarothrae), and Russian thistle (Salsola iberica). Water requirements are met by metabolizing grazed vegetation. Prairie dogs dig burrows
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NASA Astrophysics Data System (ADS)
Drummond, J.
The independent discovery of the same three streams (named alpha, beta, and gamma) among 139 Earth approaching asteroids and among 89 meteorite producing fireballs presents the possibility of matching specific meteorites to specific asteroids, or at least to asteroids in the same stream and, therefore, presumably of the same composition. Although perhaps of limited practical value, the three meteorites with known orbits are all ordinary chondrites. To identify, in general, the taxonomic type of the parent asteroid, however, would be of great scientific interest since these most abundant meteorite types cannot be unambiguously spectrally matched to an asteroid type. The H5 Pribram meteorite and asteroid 4486 (unclassified) are not part of a stream, but travel in fairly similar orbits. The LL5 Innisfree meteorite is orbitally similar to asteroid 1989DA (unclassified), and both are members of a fourth stream (delta) defined by five meteorite-dropping fireballs and this one asteroid. The H5 Lost City meteorite is orbitally similar to 1980AA (S type), which is a member of stream gamma defined by four asteroids and four fireballs. Another asteroid in this stream is classified as an S type, another is QU, and the fourth is unclassified. This stream suggests that ordinary chondrites should be associated with S (and/or Q) asteroids. Two of the known four V type asteroids belong to another stream, beta, defined by five asteroids and four meteorite-dropping (but unrecovered) fireballs, making it the most probable source of the eucrites. The final stream, alpha, defined by five asteroids and three fireballs is of unknown composition since no meteorites have been recovered and only one asteroid has an ambiguous classification of QRS. If this stream, or any other as yet undiscovered ones, were found to be composed of a more practical material (e.g., water or metalrich), then recovery of the associated meteorites would provide an opportunity for in-hand analysis of a potential near-Earth resource.
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NASA Technical Reports Server (NTRS)
Drummond, J.
1991-01-01
The independent discovery of the same three streams (named alpha, beta, and gamma) among 139 Earth approaching asteroids and among 89 meteorite producing fireballs presents the possibility of matching specific meteorites to specific asteroids, or at least to asteroids in the same stream and, therefore, presumably of the same composition. Although perhaps of limited practical value, the three meteorites with known orbits are all ordinary chondrites. To identify, in general, the taxonomic type of the parent asteroid, however, would be of great scientific interest since these most abundant meteorite types cannot be unambiguously spectrally matched to an asteroid type. The H5 Pribram meteorite and asteroid 4486 (unclassified) are not part of a stream, but travel in fairly similar orbits. The LL5 Innisfree meteorite is orbitally similar to asteroid 1989DA (unclassified), and both are members of a fourth stream (delta) defined by five meteorite-dropping fireballs and this one asteroid. The H5 Lost City meteorite is orbitally similar to 1980AA (S type), which is a member of stream gamma defined by four asteroids and four fireballs. Another asteroid in this stream is classified as an S type, another is QU, and the fourth is unclassified. This stream suggests that ordinary chondrites should be associated with S (and/or Q) asteroids. Two of the known four V type asteroids belong to another stream, beta, defined by five asteroids and four meteorite-dropping (but unrecovered) fireballs, making it the most probable source of the eucrites. The final stream, alpha, defined by five asteroids and three fireballs is of unknown composition since no meteorites have been recovered and only one asteroid has an ambiguous classification of QRS. If this stream, or any other as yet undiscovered ones, were found to be composed of a more practical material (e.g., water or metalrich), then recovery of the associated meteorites would provide an opportunity for in-hand analysis of a potential near-Earth resource.
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Zheng, Zhu; Wang-Yuan, Wei; Qian-Hui, Liu; Ben-Jiao, Hu; Ze-Min, Sun
2017-01-19
To evaluate the effects of the project of ditching for drain on Oncomelania hupensis snail control and flood prevention security and explore the optimal engineering design plan in Dongting Lake region. A retrospective study was performed on the previous studies about the project of ditching for drain. The reference values of project indices were determined. The outside levee of Nanhu New Distinct of Yueyang City in Dongting Lake region was selected as the study area, and the cross section of marshland perpendicular to the center line of the levee was extracted to research. According to the situations of various water levels, a dynamic simulation was performed on the effect and security of the project of ditching for drain through the software FLAC 3D . The retrospective study showed that the project would be effective when the relatively subsoil water level decreased by 0.35 m, and the soil water content decreased correspondingly. The dynamic simulation by FLAC 3D showed that the minimum safe distances between transverse ditch 1, vertical ditch and levee toe should be 25 m and 13 m respectively. The digging depth of transverse ditch and vertical ditch should be 1.2 m and 1.0 m respectively. If the width of marshland in drought period was less than 500 m, one transverse ditch was efficient. Otherwise, more transverse ditches should be set with the intervals of 300 m. The project of ditching for drain is an effective ecological snail elimination method. Optimizing the digging depth of ditches and distances between transverse ditches, vertical ditch and levee toe will ensure the effects and security of the project.
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Asteroid selection for mission opportunities. Appendix: Asteroid data sheets
NASA Technical Reports Server (NTRS)
1972-01-01
The characteristics of asteroids selected as possible space mission objectives are presented. The asteroids are described according to: (1) magnitude, (2) spectral reflectivity; (3) phase factors, (4) polarization, (5) light curve, and (6) physical parameters. The data are tabulated on specific formats for each asteroid considered.
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Asteroid surface mineralogy: Evidence from earth-based telescope observations
NASA Technical Reports Server (NTRS)
Mccord, T. B.
1978-01-01
The interpretation of asteroid reflectance spectrophotometry in terms of mineralogical types gives inferred mineral assemblages for about 60 asteroids. Asteroid surface materials are compared with similar materials that make up many meteorites. The absence of asteroids with spectra that match identically the ordinary chondrites is noted.
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NASA Astrophysics Data System (ADS)
Nishino, Hideo; Tateishi, Kohei; Ishikawa, Masashi; Furukawa, Takashi; Goka, Motoki
2018-07-01
Guided wave inspection is expected especially for buried piping because it can be applied easily to such piping requiring only its partial digging from the ground. However, in buried piping, the attenuation coefficient is extremely large compared with that in above-ground piping because the leaky \\text{T}(0,1) mode guided wave (LTGW) propagates in buried piping and its energy leaks into the adjacent surrounding material as a bulk shear wave. Petrolatum anticorrosion grease (PAG) is the most widely used as the coating material on the pipe surface before burying piping in sand or soil, which is a viscous material with a temperature-dependent shear wave velocity. In this paper, attenuation characteristics of the LTGW are shown theoretically and experimentally. The theoretical calculations explain very well the experimental results measured. The temperature dependence of the attenuation coefficient is discussed with the theoretical outcomes.
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The team from Iowa State University received second place in the Outreach Project category. At left is retired NASA astronaut Jerry Ross. At right is Bethanne Hull, NASA Education specialist and lead Outreach Project judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The University of Alabama Team Astrobotics received first place in the Outreach Project category. At left is retired NASA astronaut Jerry Ross. At right is Bethanne Hull, NASA Education specialist and lead Outreach Project judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The University of Alabama Team Astrobotics received first place for their Systems Engineering Paper. At left is retired NASA astronaut Jerry Ross. At right is Jonette Stecklein, lead systems engineering paper judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The University of Alabama Team Astrobotics received first place in the On-Site Mining Award. At left is retired NASA astronaut Jerry Ross. At right is Rob Mueller, lead mining judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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2014-05-21
CAPE CANAVERAL, Fla. – Team members from the University of Florida in Gainesville prepare their robot for the mining portion of NASA's 2014 Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Frankie Martin
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The University of Alabama Team Astrobotics received third place in the Slide Presentation and Demonstration award category. At left is retired NASA astronaut Jerry Ross. At right is Daniel Hull, lead presentation judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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2014-05-21
CAPE CANAVERAL, Fla. – The Hawai'l Marsbot Team members from Kapi'olani Community College in Hawaii prepare their robot for the mining portion of NASA's 2014 Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Frankie Martin
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2014-05-22
CAPE CANAVERAL, Fla. – A mining competition participant talks with a representative at the Ground Systems Development and Operations booth during NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The team from The University of Akron received third place for their Systems Engineering Paper. At left is retired NASA astronaut Jerry Ross. At right is Jonette Stecklein, lead systems engineering paper judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The University of Alabama Team Astrobotics received the Efficient Use of Communications Power Award. At left is retired NASA astronaut Jerry Ross. At right is Kurt Leucht, a NASA engineer in Swamp Works and event emcee. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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2014-05-22
CAPE CANAVERAL, Fla. – College and university teams prepare their robots for the mining portion of NASA’s 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The team from Kent State University received third place in the On-Site Mining Award. At left is retired NASA astronaut Jerry Ross. At right is Rob Mueller, lead mining judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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2014-05-23
CAPE CANAVERAL, Fla. -- Team members from the University of Akron in Ohio take a break before their final mining run on the final day of NASA's 2014 Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from colleges and universities around the U.S. designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Kim Shiflett
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2014-05-21
CAPE CANAVERAL, Fla. – Team members from the University of Alabama prepare their robot for the mining portion of NASA's 2014 Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Frankie Martin
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2014-05-21
CAPE CANAVERAL, Fla. – Team members from the University of North Dakota prepare their robot for the mining portion of NASA's 2014 Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Frankie Martin
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2014-05-21
CAPE CANAVERAL, Fla. – Members of the West Virginia University color guard stand at attention during presentation of the U.S. Flag at the opening ceremony of NASA’s 2014 Robotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 35 teams from around the U.S. have designed and built remote-controlled robots for the mining competition. The competition is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in science, technology, engineering and mathematics, or STEM, fields by expanding opportunities for student research and design. Teams use their remote-controlled robotics to maneuver and dig in a supersized sandbox filled with a crushed material that has characteristics similar to Martian soil. The objective of the challenge is to see which team’s robot can collect and move the most regolith within a specified amount of time. For more information, visit www.nasa.gov/nasarmc. Photo credit: NASA/Frankie Martin
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Quaternary geologic map of the Lake Erie 4 degrees x 6 degrees quadrangle, United States and Canada
Fullerton, David S.; Richmond, Gerald M.; state compilations by Fullerton, David S.; Cowan, W.R.; Sevon, W.D.; Goldthwait, R.P.; Farrand, W.R.; Muller, E.H.; Behling, R.E.; Stravers, J.A.; edited and integrated by Fullerton, David S.; Richmond, Gerald Martin
1991-01-01
The Quaternary Geologic Map of the Lake Erie 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Quebec 4 degrees x 6 degrees quadrangle, United States and Canada
State compilations by Borns, H. W.; Gadd, N.R.; LaSalle, Pierre; Martineau, Ghismond; Chauvin, Luc; Fulton, R.J.; Chapman, W.F.; Wagner, W.P.; Grant, D.R.; edited and integrated by Richmond, Gerald Martin; Fullerton, David S.
1987-01-01
The Quaternary Geologic Map of the Quebec 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Chicago 4 degrees x 6 degrees quadrangle, United States
State compilations by Lineback, Jerry A.; Bleuer, Ned K.; Mickelson, David M.; Farrand, William R.; Goldthwait, Richard P.; Edited and integrated by Richmond, Gerald M.; Fullerton, David S.
1983-01-01
The Quaternary Geologic Map of the Chicago 4 degree x 6 degree Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Sudbury 4 degree by 6 degree quadrangle, United States and Canada
Fullerton, David S.; Sado, Edward V.; Baker, C.L.; Farrand, William R.
2004-01-01
The Quaternary Geologic Map of the Sudbury 4 degrees x 6 degrees Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Ottawa 4 degrees x 6 degrees quadrangle, United States and Canada
Fullerton, David S.; Gadd, N. R.; Veillette, J.J.; Wagner, P.W.; Chapman, W.F.
1993-01-01
The Quaternary Geologic Map of the Ottawa 4 degree x 6 degree Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Dallas 4° x 6° quadrangle, United States
State compilations by Luza, Kenneth V.; Jensen, Kathryn M.; Fishman, W.D.; Wermund, E.G.; Richmond, Gerald Martin; edited and integrated by Richmond, Gerald Martin; Christiansen, Ann Coe; Bush, Charles A.
1994-01-01
The Quaternary Geologic Map of the Dallas 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Chesapeake Bay 4 degrees x 6 degrees quadrangle, United States
State compilations by Cleaves, Emery T.; Glaser, John D.; Howard, Alan D.; Johnson, Gerald H.; Wheeler, Walter H.; Sevon, William D.; Judson, Sheldon; Owens, James P.; Peebles, Pamela C.; edited and integrated by Richmond, Gerald Martin; Fullerton, David S.; Weide, David L.
1987-01-01
The Quaternary Geologic Map of the Chesapeake Bay 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Richmond, Gerald M.; Fullerton, David S.; state compilations by Farrand, William R.; Mickelson, D.M.; Cowan, W.R.; Goebel, J.E.; edited and integrated by Richmond, Gerald Martin
1984-01-01
The Quaternary Geologic Map of the Lake Superior 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Hudson River 4 degree x 6 degree quadrangle, United States and Canada
State and province compilations by Fullerton, David S.; Sevon, William D.; Muller, Ernest H.; Judson, Sheldon; Black, Robert F.; Wagner, Phillip W.; Hartshorn, Joseph H.; Chapman, William F.; Cowan, William D.; edited and integrated by Fullerton, David S.
1992-01-01
The Quaternary Geologic Map of the Hudson River 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Ozark Plateau 4 ° x 6 ° quadrangle, United States
State compilations by Whitfield, John William; Ward, R.A.; Denne, J.E.; Holbrook, D.F.; Bush, W.V.; Lineback, J.A.; Luza, K.V.; Jensen, Kathleen M.; Fishman, W.D.; Richmond, Gerald Martin; Weide, David L.; Bush, Charles A.
1993-01-01
The Quaternary Geologic Map of the Ozark Plateau 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Quaternary geologic map of the Boston 4 degrees x 6 degrees quadrangle, United States and Canada
State compilations by Hartshorn, Joseph H.; Thompson, W.B.; Chapman, W.F.; Black, R.F.; Richmond, Gerald Martin; Grant, D.R.; Fullerton, David S.; edited and integrated by Richmond, Gerald Martin
1991-01-01
The Quaternary Geologic Map of the Boston 4 deg x 6 deg Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.
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Robotic Mining Competition - Awards Ceremony
2018-05-18
NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The team from The University of Akron received third place in the Outreach Project category. At left is retired NASA astronaut Jerry Ross. At right is Bethanne Hull, NASA Education specialist and lead Outreach Project judge. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.
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NASA Technical Reports Server (NTRS)
Gaffey, Michael J.; Kelley, Michael S.; Hardersen, Paul S.
2002-01-01
Studies of meteorites and observations of asteroids can provide important constraints on the formation and evolution of asteroid families. The iron meteorites alone require the disruption of 85 differentiated asteroids, and the potential formation of 85 families. Additional information is contained in the original extended abstract.
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REVIEWS OF TOPICAL PROBLEMS: Satellites of asteroids
NASA Astrophysics Data System (ADS)
Prokof'eva, Valentina V.; Tarashchuk, V. P.; Gor'kavyi, N. N.
1995-06-01
More than 6000 asteroids in the Solar System have now been discovered and enumerated, and about 500 of them have been investigated in detail by different methods. This rewiew gives observational evidence which indicates that no fewer than 10% of asteroids may be composed of two or more bodies. This was supported by the detection of a satellite of the asteroid Ida by the Galileo spacecraft. This discovery symbolises the change of both observational and theoretical paradigms. Space and ground observations of asteroids by modern teghniques may give extensive new data for modelling double asteroids. The analysis of problems of stability, formation and dynamics of asteroid satellites shows that their sphere of stable motion extends up to several hundred asteroid radii. The idea that the origin of the asteroid satellites may be explained in the frame of a unified accretion model of planetary satellite formation is proposed and justified.
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NASA Technical Reports Server (NTRS)
Harris, A. W.; Burns, J. A.
1979-01-01
Rotation properties and shape data for 182 asteroids are compiled and analyzed, and a collisional model for the evolution of the mean rotation rate of asteroids is proposed. Tabulations of asteroid rotation rates, taxonomic types, pole positions, sizes and shapes and plots of rotation frequency and light curve amplitude against size indicate that asteroid rotational frequency increases with decreasing size for all asteroids except those of the C or S classes. Light curve data also indicate that small asteroids are more irregular in shape than large asteroids. The dispersion in rotation rates observed is well represented by a three dimensional Maxwellian distribution, suggestive of collisional encounters between asteroids. In the proposed model, the rotation rate is found to tend toward an equilibrium value, at which spin-up due to infrequent, large collisions is balanced by a drag due to the larger number of small collisions. The lower mean rotation rate of C-type asteroids is attributed to a lower means density of that class, and the increase in rotation rate with decreasing size is interpreted as indicative of a substantial population of strong asteroids.
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NASA Astrophysics Data System (ADS)
Jacobs, B. E.; Bohls-Graham, C. E.; Ellins, K. K.; Riggs, E. M.; Serpa, L. F.; Stocks, E.; McIver, H.; Sergent, C.
2015-12-01
The development of the Next Generation Science Standards (NGSS) as a framework around which to guide K-12 science instruction has generated a call for rigorous curricula that meets the demand for developing a workforce with expertise in tackling modern Earth science challenges. The Diversity and Innovation in Geosciences (DIG) Texas Blueprints project addresses this need for quality, aligned curricula with educator-vetted, freely available resources carefully selected and compiled into three week thematic units that have been aligned with the Earth Science Literacy Principles and the NGSS. These units can then be packaged into customized blueprints for a year-long Earth & Space Science course that engages students in the relevant disciplinary core ideas, crosscutting concepts and science and engineering practices. As part of supporting NGSS-congruent instruction, each unit has extensive scaffolding notes for the learning activities selected for that unit. Designed with both the new and veteran teacher in mind, these scaffolding notes yield information regarding advanced teacher preparation, student prerequisite skills, and potential challenges that might arise during classroom implementation. Feedback from Texas high school teachers implementing the DIG Texas Blueprints in the classroom, in addition to that of university secondary education majors in a preparation course utilizing the blueprints, instigated the most recent revisions to these scaffolding notes. The DIG Texas Blueprints Educator Intern Team charged with these revisions then determined which learning activities became candidates for either inclusion in the refined units, retention as an additional resource, or elimination from the blueprints. This presentation will focus on the development of these scaffolding notes and their role in supporting congruence with the NGSS. A review of the second year of implementation of the blueprints and the feedback that generated the final revisions will be shared, as well as the current accessibility status of the DIG Texas Blueprints resources
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NASA Astrophysics Data System (ADS)
Ellins, K. K.; Bohls-Graham, E.; Riggs, E. M.; Serpa, L. F.; Jacobs, B. E.; Martinez, A. O.; Fox, S.; Kent, M.; Stocks, E.; Pennington, D. D.
2014-12-01
The NSF-sponsored DIG Texas Instructional Blueprint project supports the development of online instructional blueprints for a yearlong high school-level Earth science course. Each blueprint stitches together three-week units that contain curated educational resources aligned with the Texas state standards for Earth and Space Science and the Earth Science Literacy Principles. Units focus on specific geoscience content, place-based concerns, features or ideas, or other specific conceptual threads. Five regional teams composed of geoscientists, pedagogy specialists, and practicing science teachers chose unit themes and resources for twenty-two units during three workshops. In summer 2014 three Education Interns (Earth science teachers) spent six weeks refining the content of the units and aligning them with the Next Generation Science Standards. They also assembled units into example blueprints. The cross-disciplinary collaboration among blueprint team members allowed them to develop knowledge in new areas and to share their own discipline-based knowledge and perspectives. Team members and Education Interns learned where to find and how to evaluate high quality geoscience educational resources, using a web-based resource review tool developed by the Science Education Resource Center (SERC). SERC is the repository for the DIG Texas blueprint web pages. Work is underway to develop automated tools to allow educators to compile resources into customized instructional blueprints by reshuffling units within an existing blueprint, by mixing units from other blueprints, or creating new units and blueprints. These innovations will enhance the use of the units by secondary Earth science educators beyond Texas. This presentation provides an overview of the project, shows examples of blueprints and units, reports on the preliminary results of classroom implementation by Earth science teachers, and considers challenges encountered in developing and testing the blueprints. The project is a collaboration between The University of Texas at Austin, The University of Texas at El Paso, and Texas A&M University, all of which participate in the DIG Texas alliance. Website:serc.carleton.edu/dig_blueprints/index.html
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Cooling induces phase separation in membranes derived from isolated CNS myelin
Pusterla, Julio M.; Schneck, Emanuel; Funari, Sérgio S.; Démé, Bruno; Tanaka, Motomu
2017-01-01
Purified myelin membranes (PMMs) are the starting material for biochemical analyses such as the isolation of detergent-insoluble glycosphingolipid-rich domains (DIGs), which are believed to be representatives of functional lipid rafts. The normal DIGs isolation protocol involves the extraction of lipids under moderate cooling. Here, we thus address the influence of cooling on the structure of PMMs and its sub-fractions. Thermodynamic and structural aspects of periodic, multilamellar PMMs are examined between 4°C and 45°C and in various biologically relevant aqueous solutions. The phase behavior is investigated by small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC). Complementary neutron diffraction (ND) experiments with solid-supported myelin multilayers confirm that the phase behavior is unaffected by planar confinement. SAXS and ND consistently show that multilamellar PMMs in pure water become heterogeneous when cooled by more than 10–15°C below physiological temperature, as during the DIGs isolation procedure. The heterogeneous state of PMMs is stabilized in physiological solution, where phase coexistence persists up to near the physiological temperature. This result supports the general view that membranes under physiological conditions are close to critical points for phase separation. In presence of elevated Ca2+ concentrations (> 10 mM), phase coexistence is found even far above physiological temperatures. The relative fractions of the two phases, and thus presumably also their compositions, are found to vary with temperature. Depending on the conditions, an “expanded” phase with larger lamellar period or a “compacted” phase with smaller lamellar period coexists with the native phase. Both expanded and compacted periods are also observed in DIGs under the respective conditions. The observed subtle temperature-dependence of the phase behavior of PMMs suggests that the composition of DIGs is sensitive to the details of the isolation protocol. PMID:28915267
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Constraints on the size of Asteroid (216) Kleopatra using stress analysis
NASA Astrophysics Data System (ADS)
Hirabayashi, M.; Scheeres, D. J.
2013-12-01
We investigate the stable size of Asteroid (216) Kleopatra by considering structural constraints on this body. Comprehensive radar observations (Ostro et al. 2000, Science) were used to estimate a shape model for this asteroid. Their estimation revealed that the shape looks like a dog-bone, the mean radius is 54.3 km (with uncertainty as large as 25%), and the surface seems similar to lunar surface regolith. However, 10 years later, Descamps et al. (2011, Icarus) performed near-infrared adaptive optics (AO) imaging with the W.M. Keck II telescope and found that although the shape may be consistent with their observation result, their size appeared to be larger than the Ostro size (by a factor of about 1.24). Our motivation in this study is to investigate structural stability constraints on the size of this asteroid. Across the stated range of uncertainty we find significant differences in the necessary angle of friction and cohesion for the body to avoid plastic deformation. We use the following physical parameters as fixed: a mass of 4.64e18 kg (Descamps et al. 2011, Icarus), a rotation period of 5.385 hr (Magnusson 1990, Icarus), and the Ostro et al. shape. We use the Drucker-Prager criterion to describe the rheology of the asteroid's material. Furthermore, we determine the friction angle from the fact that the surface of this asteroid is similar to lunar surface regolith, whose porosity ranges from 33% to 55%. According to Scott (1963), a soil with porosity of 44% (the mean value of the lunar surface porosity) has a friction angle of 32 degrees (which we use as our nominal value). Since the interior structure is unknown, we assume that the body is homogeneous. We first analyze the stable size by using the upper bound theorem from limit analysis on the assumption that this asteroid's materials are cohesionless. Based on this theorem, for any static surface traction and body force, the yield due to a smooth and convex yield envelope associated with the volume average is identical to the upper bound (Holsapple 2008, INT J NONLINEAR MECH). For the average stress, we give total volume (Holsapple, 2008, Icarus) and partial volume (Hirabayashi et al., 2013, ApJ, submitted). This method gives a conservative condition for structural failure. The result shows that if the size is between 1.18 and 1.32 (a scaling factor defined such that the Ostro shape's size has a value of 1.0), (216) Kleopatra is structurally stable, which is consistent with Descamps et al. (2011, Icaurus). Next, we calculate plastic stress solutions to determine possible actual structural failure regimes. For this computation, we use commercial finite element analysis software (ANSYS Academic Teaching Introductory 14.0). To determine structural failure, we search for the condition where a plastic region propagates over the majority of a cross section. Since the zero-cohesion condition leads to large plastic deformations, we evaluate the stable size as a function of cohesion under the constant friction angle 32 degree. The result shows that if the size is 1.24, the necessary cohesion required is 90000 Pa; otherwise, the value dramatically increases up to 1e6 Pa. This technique is robust; therefore, once we obtain accurate physical parameters from more detail observations, our methodology will be able to give stronger constraints (216) Kleopatra, as well as other rubble pile asteroids.
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Physical studies of asteroids. XXXII. Rotation periods and UBVRI-colours for selected asteroids
NASA Astrophysics Data System (ADS)
Piironen, J.; Lagerkvist, C.-I.; Erikson, A.; Oja, T.; Magnusson, P.; Festin, L.; Nathues, A.; Gaul, M.; Velichko, F.
1998-03-01
We present lightcurves of selected asteroids. Most of the asteroids were included to obtain refined spin periods. Enhanced periods were determined for 11 Parthenope, 306 Unitas and 372 Palma. We confirmed the spin periods of 8 Flora, 13 Egeria, 71 Niobe, 233 Asterope, 291 Alice, 409 Aspasia, 435 Ella and 512 Taurinensis. We determined also BV-colours for most of the included asteroids and UBVRI-colours for a total of 22 asteroids.
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Simultaneous Mass Determination for Gravitationally Coupled Asteroids
NASA Astrophysics Data System (ADS)
Baer, James; Chesley, Steven R.
2017-08-01
The conventional least-squares asteroid mass determination algorithm allows us to solve for the mass of a large subject asteroid that is perturbing the trajectory of a smaller test asteroid. However, this algorithm is necessarily a first approximation, ignoring the possibility that the subject asteroid may itself be perturbed by the test asteroid, or that the encounter’s precise geometry may be entangled with encounters involving other asteroids. After reviewing the conventional algorithm, we use it to calculate the masses of 30 main-belt asteroids. Compared to our previous results, we find new mass estimates for eight asteroids (11 Parthenope, 27 Euterpe, 51 Neimausa, 76 Freia, 121 Hermione, 324 Bamberga, 476 Hedwig, and 532 Herculina) and significantly more precise estimates for six others (2 Pallas, 3 Juno, 4 Vesta, 9 Metis, 16 Psyche, and 88 Thisbe). However, we also find that the conventional algorithm yields questionable results in several gravitationally coupled cases. To address such cases, we describe a new algorithm that allows the epoch state vectors of the subject asteroids to be included as solve-for parameters, allowing for the simultaneous solution of the masses and epoch state vectors of multiple subject and test asteroids. We then apply this algorithm to the same 30 main-belt asteroids and conclude that mass determinations resulting from current and future high-precision astrometric sources (such as Gaia) should conduct a thorough search for possible gravitational couplings and account for their effects.
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Asteroid Lightcurve Analysis at Isaac Aznar Observatory Aras De Los Olmos, Valencia, Spain
NASA Astrophysics Data System (ADS)
Macias, Amadeo Aznar
2015-01-01
The Isaac Aznar Observatory conducts astrometric and photometric studies of asteroids. This paper contains the photometric results of four asteroids obtained from 2014 April to August. These asteroids were selected from the Collaborative Asteroid Lightcurve Link (CALL) web site: 1088 Mitaka, 2956 Yeomans, 3894 Williamcooke, and (4555) 1974QL.
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NASA Astrophysics Data System (ADS)
Zhang, Fei; Xu, Bo; Circi, Christian; Zhang, Lei
2017-04-01
Kinetic impact may be the most reliable and easily implemented method to deflect hazardous asteroids using current technology. Depending on warning time, it can be effective on asteroids with diameters of a few hundred meters. Current impact deflection research often focuses on the orbital dynamics of asteroids. In this paper, we use the ejection outcome of a general oblique impact to calculate how an asteroid's rotational and translational state changes after impact. The results demonstrate how small impactors affect the dynamical state of small asteroids having a diameter of about 100 m. According to these consequences, we propose using several small impactors to hit an asteroid continuously and gently, making the deflection mission relatively flexible. After calculating the rotational variation, we find that the rotational state, especially of slender non-porous asteroids, can be changed significantly. This gives the possibility of using multiple small impactors to mitigate a potentially hazardous asteroid by spinning it up into pieces, or to despin one for future in-situ investigation (e.g., asteroid retrieval or mining).
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NASA Astrophysics Data System (ADS)
Okazaki, M.; Sasaki, S.; Tsuchiyama, A.; Miyake, A.; Matsumoto, T.; Hirata, T.; Hiroi, T.
2014-07-01
Space weathering is the process invoked to explain the spectral mismatch between S-type asteroids and ordinary chondrites: darkening, spectral reddening, and attenuation of absorption bands in the reflectance spectra. These changes of optical properties of the surface of airless silicate bodies are explained by nanophase metallic iron (nanoFe) particles, which are formed on regolith particles by high-velocity dust impacts as well as irradiation of the solar-wind ions (Hapke 2001). Those nanoFe particles were discovered in lunar soils, Kapoeta meteorite, and regolith grains from the surface of S-type asteroid Itokawa. Experimental studies using a nano-second-pulse laser confirmed that nanoFe should control the spectral darkening and reddening. The observed reddening of S-type asteroid families is correlated with dynamical asteroid ages after family-forming disruption (Jedicke, et al. 2004). Still, experiments showed that the weathering degree should depend on the composition such as the olivine/pyroxene ratio (Hiroi and Sasaki 2001). In ordinary chondrites, iron sulfides, typically, troilite FeS is the main sulfur-bearing mineral. TEM observation of a dust grain of Itokawa showed the presence of not only iron, but also nanophase FeS particles, which are embedded within a vapor-deposited thin surface layer (thinner than 10-15 nm; Noguchi et al. 2011). One of the Itokawa grains is composed mainly of FeS (about 40 microns) with smaller olivine and pyroxene particles (Yada et al., 2014). On the other hand, the surface sulfur depletion of S-type asteroid Eros was explained by the same mechanism (high-velocity dust and solar-wind particle impacts) of space weathering (Loeffler et al. 2008). To examine the effect of FeS on the surface optical properties of silicate bodies, we conducted pulse-laser irradiation experiments on mixtures of olivine (and pyroxene) and FeS particles with typical sizes of 45--75 micron, for varying FeS fractions (0--0.2 by weight). We find that the addition of Fes should promote the change of optical properties in accordance with space weathering, especially darkening. As compared to the cases where iron particles are mixed, darkening occurs characteristically in the infrared region. According to preliminary observations by the FESEM and HR microscopes, surfaces of olivine particles --- after laser irradiation --- are likely to be coated with vapor-deposited material. Moreover, some grains are covered by a smooth thicker FeS coating, which would contribute to the overall darkening. We suppose that iron sulfides may promote space weathering initially, even if some of the sulfides are, in time, decomposed to a lower surface sulfur abundance on small asteroids.
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Big maggots dig deeper: size-dependent larval dispersal in flies.
Davis, Jeremy M; Coogan, Laura E; Papaj, Daniel R
2015-09-01
The ability of individual animals to select habitats optimal for development and survival can be constrained by the costs of moving through the environment. Animals that seek overwintering sites underground, for example, may be constrained by the energy required to burrow into the soil. We conducted field and laboratory studies to determine the relationship between individual size and overwintering site selection in the tephritid flies, Rhagoletis juglandis and Rhagoletis suavis. We also explored the effect of site selection on pupal mortality, parasitism, and the ability to emerge from overwintering sites after eclosion. In both species, and in both lab and field tests, larger pupae were found at deeper soil depths. In addition, marginally non-significant trends indicated pupae in deeper sites were 48% more likely to survive the overwintering period. Finally, larger individuals were more likely to eclose and emerge from the soil at a given depth, but flies in deep overwintering sites were less likely to emerge from those sites than flies in shallow sites. Our data indicate that overwintering site selection represents a trade-off between avoiding predators and parasites that occur at shallow sites, and the energetic and mortality costs of burrowing to, overwintering in, and emerging from, deeper sites. The size-dependent overwintering site selection demonstrated here has implications for population dynamics and pest control strategies. Some fly control measures, such as the introduction of parasites or predators, will be mitigated when the deepest and least accessible overwintering pupae represent a disproportionately large amount of the population's reproductive capacity.
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Every rural resident knows that the geosciences matter!
NASA Astrophysics Data System (ADS)
Richter, D. D., Jr.
2017-12-01
For thirty years we have been working in the forests and soils of rural South Caroilna. Perhaps the most important thing we do is keep long-running field experiments alive (experiments that long pre-date us). We also pay a lot of attention to environmental history. We've watched the local kids grow up as we've also gotten to know many people in the local communities of European and African origin. While we certainly need to attend more church gatherings, we have attended a few, and while some profess that we must be digging for gold, nearly all have grown to respect us. Probably this is in part because we don't go away, and we so doggedly believe in place-base research. After all, we study what rural people depend on - the land, soil, water, trees, crops, and air. We've given data of soil chemistry to cooperative farmers, historic maps as Christmas presents, books as gifts for letting us drill deep groundwater wells into the underlying granite (because the USFS would take years for NEPA to approve our proposed well), and flowers to simply generous neighbors. We've also accepted garden produced okra, corn, and potatoes. After 30 years, I may be naive, but if you respect the land as any critical zonist (Earth scientist) must, we need place-based geological research like critical zone observatories and rural folks not only need to become part of the research, they are willing to do so.
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Implementing Classification on a Munitions Response Project
2011-12-01
Detection Dig List IVS/Seed Site Planning Decisions Dig All Anomalies Site Characterization Implementing Classification on a Munitions Response...Details ● Seed emplacement ● EM61-MK2 detection survey RTK GPS ● Select anomalies for further investigation ● Collect cued data using MetalMapper...5.2 mV in channel 2 938 anomalies selected ● All QC seeds detected using this threshold Some just inside the 60-cm halo ● IVS reproducibility
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Workshop on Past and Present Solar Radiation: The Record in Meteoritic and Lunar Regolith Material
NASA Technical Reports Server (NTRS)
Pepin, R. O. (Compiler); Mckay, D. S. (Compiler)
1986-01-01
The principal question addressed in the workshop was the extent to which asteroidal and lunar regoliths have collected and preserved, in meteoritic regolith breccias and in lunar soils and regolith breccias, a record of the flux, energy, and compositional history of the solar wind and solar flares. Six central discussion topics were identified. They are: (1)Trapped solar wind and flare gases, tracks, and micrometeorite pits in regolith components; (2)Comparison between lunar regolith breccias, meteoritic regolith breccias, and the lunar soil; (3)The special role of regolith breccias and the challenge of dating their times of compaction; (4)Implications of the data for the flux and compositional history of solar particle emission, composition, and physical mechanisms in the solar source regions, and the composition of the early nebula; (5)How and to what extent have records of incident radiation been altered in various types of grains; (6)Future research directions
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NASA Technical Reports Server (NTRS)
Mckay, Mary Fae (Editor); Mckay, David S. (Editor); Duke, Michael B. (Editor)
1992-01-01
Space resources must be used to support life on the Moon and in the exploration of Mars. Just as the pioneers applied the tools they brought with them to resources they found along the way rather than trying to haul all their needs over a long supply line, so too must space travelers apply their high technology tools to local resources. This overview describes the findings of a study on the use of space resources in the development of future space activities and defines the necessary research and development that must precede the practical utilization of these resources. Space resources considered included lunar soil, oxygen derived from lunar soil, material retrieved from near-Earth asteroids, abundant sunlight, low gravity, and high vacuum. The study participants analyzed the direct use of these resources, the potential demand for products from them, the techniques for retrieving and processing space resources, the necessary infrastructure, and the economic tradeoffs.
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Hybrid rocket propellants from lunar material
NASA Astrophysics Data System (ADS)
Sparks, Douglas R.
This paper examines the use of lunar material for hybrid rocket propellants. Liquid oxygen is identified as the primary oxidizer and metals such as aluminum, magnesium, calcium, titanium and silicon are compared as possible fuels. Due to the reduced transportation costs, the use of lunar materials for both oxidizer and fuel will dramatically reduce the cost of a sustained space program. The advantage of hybrid rocket systems over liquid and solid rockets is discussed. It is pointed out that this type of hybrid rocket propellant could also be obtained from asteroidal and planetary soils, thereby facilitating the exploration and industrialization of the inner solar system.
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In Situ Planetary Mineralogy Using Simultaneous Time Resolved Fluorescence and Raman Spectroscopy
NASA Technical Reports Server (NTRS)
Blacksberg, J.; Rossman , G.R.
2011-01-01
Micro-Raman spectroscopy is one of the primary methods of mineralogical analysis in the laboratory, and more recently in the field. Because of its versatility and ability to interrogate rocks in their natural form it is one of the front runners for the next generation of in situ instruments designed to explore adverse set of solar system bodies (e.g. Mars, Venus, the Moon, and other primitive bodies such as asteroids and the Martian moons Phobos and Deimos), as well as for pre-selection of rock and soil samples for potential cache and return missions.
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NASA Technical Reports Server (NTRS)
Keller, Lindsay P.; Berger, Eve L.
2017-01-01
Limited samples are available for the study of space weathering effects on airless bodies. The grains returned by the Hayabusa mission to asteroid 25143 Itokawa provide the only samples currently available to study space weathering of ordinary chondrite regolith. We have previously studied olivine-rich Itokawa grains and documented their surface alteration and exposure ages based on the observed density of solar flare particle tracks. Here we focus on the rarer Itokawa plagioclase grains, in order to allow comparisons between Itokawa and lunar soil plagioclase grains for which an extensive data set exists.
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Small main-belt asteroid spectroscopic survey: Initial results
NASA Technical Reports Server (NTRS)
Xu, Shui; Binzel, Richard P.; Burbine, Thomas H.; Bus, Schelte J.
1995-01-01
The spectral characterization of small asteroids is important for understanding the evolution of their compositional and mineralogical properties. We report the results of a CCD spectroscopic survey of small main-belt asteroids which we call the Small Main-belt Asteroid Spectroscopic Survey (SMASS). Spectra of 316 asteroids were obtained, with wavelength coverage ranging from 4000 to 10000 A (0.4 to 1 micrometers). More than half of the objects in our survey have diameters less than 20 km. Survey results include the identification of the first object resembling ordinary chondrite meteorites among the main-belt asteroids (Binzel, R. P., et al, 1993) and observations of more than 20 asteroids showing basaltic achondrite spectral absorption features that strongly link Vesta as the parent body for the basaltic achondrite meteorites (Binzel, R. P., and S. Xu 1993). A potential Mars-crossing asteroid analog to ordinary chondrite meteorites (H chondrites), 2078 Nanking, is reported here. Through a principal component analysis, we have assigned classifications to the members of our sample. The majority of the small main-belt asteroids belong to S and C classes, similar to large asteroids. Our analysis shows that two new classes are justified which we label as J and O. Small asteroids display more diversity in spectral absorption features than the larger ones, which may indicate a greater variation of compositions in the small asteroid population. We found a few candidates for olivine-rich asteroids within the S class. Although the total number of olivine-rich candidates is relatively small, we present evidence suggesting that such objects are more prevalent at smaller sizes.
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NASA Technical Reports Server (NTRS)
Abell, Paul A.; Rivkin, Andy S.
2014-01-01
The joint ESA and NASA Asteroid Impact and Deflection Assessment (AIDA) mission will directly address aspects of NASA's Asteroid Initiative and will contribute to future human exploration. The NASA Asteroid Initiative is comprised of two major components: the Grand Challenge and the Asteroid Mission. The first component, the Grand Challenge, focuses on protecting Earth's population from asteroid impacts by detecting potentially hazardous objects with enough warning time to either prevent them from impacting the planet, or to implement civil defense procedures. The Asteroid Mission, involves sending astronauts to study and sample a near-Earth asteroid (NEA) prior to conducting exploration missions of the Martian system, which includes Phobos and Deimos. AIDA's primary objective is to demonstrate a kinetic impact deflection and characterize the binary NEA Didymos. The science and technical data obtained from AIDA will aid in the planning of future human exploration missions to NEAs and other small bodies. The dual robotic missions of AIDA, ESA's Asteroid Impact Monitor (AIM) and NASA's Double Asteroid Redirection Test (DART), will provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific examinations of the binary target Didymos both prior to and after the kinetic impact demonstration. The knowledge gained from this mission will help identify asteroidal physical properties in order to maximize operational efficiency and reduce mission risk for future small body missions. The AIDA data will help fill crucial strategic knowledge gaps concerning asteroid physical characteristics that are relevant for human exploration considerations at similar small body destinations.
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Compositional studies of primitive asteroids
NASA Technical Reports Server (NTRS)
Vilas, Faith
1991-01-01
Primitive asteroids in the solar system (C, P, D class and associated subclasses) are believed to have undergone less thermal processing compared with the differential (S class) asteroids. Telescopic spectra of C class asteroids show effects of aqueous alteration products produced when heating of the asteroids was sufficient to melt surface water, but not strong enough to produce differentiation. Spectrum analysis of P and D class asteroids suggests that aqueous alteration terminated in the outer belt and did not operate at the distance of Jupiter's orbit.
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Studies of asteroids, comets, and Jupiter's outer satellites
NASA Technical Reports Server (NTRS)
Bowell, Edward
1991-01-01
Observational, theoretical, and computational research was performed, mainly on asteroids. Two principal areas of research, centering on astrometry and photometry, are interrelated in their aim to study the overall structure of the asteroid belt and the physical and orbital properties of individual asteroids. Two highlights are: detection of CN emission from Chiron; and realization that 1990 MB is the first known Trojan type asteroid of a planet other than Jupiter. A new method of asteroid orbital error analysis, based on Bayesian theory, was developed.
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Asteroid exploration and utilization: The Hawking explorer
NASA Technical Reports Server (NTRS)
Carlson, Alan; Date, Medha; Duarte, Manny; Erian, Neil; Gafka, George; Kappler, Peter; Patano, Scott; Perez, Martin; Ponce, Edgar; Radovich, Brian
1991-01-01
The Earth is nearing depletion of its natural resources at a time when human beings are rapidly expanding the frontiers of space. The resources which may exist on asteroids could have enormous potential for aiding and enhancing human space exploration as well as life on Earth. With the possibly limitless opportunities that exist, it is clear that asteroids are the next step for human existence in space. This report comprises the efforts of NEW WORLDS, Inc. to develop a comprehensive design for an asteroid exploration/sample return mission. This mission is a precursor to proof-of-concept missions that will investigate the validity of mining and materials processing on an asteroid. Project STONER (Systematic Transfer of Near Earth Resources) is based on two utilization scenarios: (1) moving an asteroid to an advantageous location for use by Earth; and (2) mining an asteroids and transporting raw materials back to Earth. The asteroid explorer/sample return mission is designed in the context of both scenarios and is the first phase of a long range plane for humans to utilize asteroid resources. The report concentrates specifically on the selection of the most promising asteroids for exploration and the development of an exploration scenario. Future utilization as well as subsystem requirements of an asteroid sample return probe are also addressed.
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Asteroid exploration and utilization: The Hawking explorer
NASA Astrophysics Data System (ADS)
Carlson, Alan; Date, Medha; Duarte, Manny; Erian, Neil; Gafka, George; Kappler, Peter; Patano, Scott; Perez, Martin; Ponce, Edgar; Radovich, Brian
1991-12-01
The Earth is nearing depletion of its natural resources at a time when human beings are rapidly expanding the frontiers of space. The resources which may exist on asteroids could have enormous potential for aiding and enhancing human space exploration as well as life on Earth. With the possibly limitless opportunities that exist, it is clear that asteroids are the next step for human existence in space. This report comprises the efforts of NEW WORLDS, Inc. to develop a comprehensive design for an asteroid exploration/sample return mission. This mission is a precursor to proof-of-concept missions that will investigate the validity of mining and materials processing on an asteroid. Project STONER (Systematic Transfer of Near Earth Resources) is based on two utilization scenarios: (1) moving an asteroid to an advantageous location for use by Earth; and (2) mining an asteroids and transporting raw materials back to Earth. The asteroid explorer/sample return mission is designed in the context of both scenarios and is the first phase of a long range plane for humans to utilize asteroid resources. The report concentrates specifically on the selection of the most promising asteroids for exploration and the development of an exploration scenario. Future utilization as well as subsystem requirements of an asteroid sample return probe are also addressed.
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NASA Technical Reports Server (NTRS)
Marr, Greg; Cooley, Steve; Roithmayr, Carlos; Kay-Bunnell, Linda; Williams, Trevor
2004-01-01
The Autonomous NanoTechnology Swarm (ANTS) is a generic mission architecture based on spatially distributed spacecraft, autonomous and redundant components, and hierarchical organization. The ANTS Prospecting Asteroid Mission (PAM) is an ANTS application which will nominally use a swarm of 1000 spacecraft. There would be 10 types of "specialists" with common spacecraft buses. There would be 10 subswarms of approximately 100 spacecraft each or approximately 10 of each specialist in each swarm. The ANTS PAM primary objective is the exploration of the asteroid belt in search of resources and material with astrobiologically relevant origins and signatures. The ANTS PAM spacecraft will nominally be released from a station in an Earth-Moon L1 libration point orbit, and they will use Solar sails for propulsion. The sail structure would be highly flexible, capable of changing morphology to change cross-section for capture of sunlight or to form effective "tip vanes" for attitude control. ANTS PAM sails would be capable of full to partial deployment, to change effective sail area and center of pressure, and thus allow attitude control. Results of analysis of a transfer trajectory from Earth to a sample target asteroid will be presented. ANTS PAM will require continuous coverage of different asteroid locations as close as one to two asteroid "diameters" from the surface of the asteroid for periods of science data collection during asteroid proximity operations. Hovering spacecraft could meet the science data collection objectives. The results of hovering analysis will be presented. There are locations for which hovering is not possible, for example on the illuminated side of the asteroid. For cases where hovering is not possible, the results of utilizing asteroid formations to orbit the asteroid and achieve the desired asteroid viewing will be presented for sample asteroids. The ability of ANTS PAM to reduce the area of the solar sail during asteroid proximity operations is critical to the maintenance of orbiting formations for a period of time. Results of analysis of potential "traffic" problems during asteroid proximity operations will be presented.
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Lunar and Planetary Science XXXV: Asteroids, Meteors, Comets
NASA Technical Reports Server (NTRS)
2004-01-01
Reports included:Long Term Stability of Mars Trojans; Horseshoe Asteroids and Quasi-satellites in Earth-like Orbits; Effect of Roughness on Visible Reflectance Spectra of Planetary Surface; SUBARU Spectroscopy of Asteroid (832) Karin; Determining Time Scale of Space Weathering; Change of Asteroid Reflectance Spectra by Space Weathering: Pulse Laser Irradiation on Meteorite Samples; Reflectance Spectra of CM2 Chondrite Mighei Irradiated with Pulsed Laser and Implications for Low-Albedo Asteroids and Martian Moons; Meteorite Porosities and Densities: A Review of Trends in the Data; Small Craters in the Inner Solar System: Primaries or Secondaries or Both?; Generation of an Ordinary-Chondrite Regolith by Repetitive Impact; Asteroid Modal Mineralogy Using Hapke Mixing Models: Validation with HED Meteorites; Particle Size Effect in X-Ray Fluorescence at a Large Phase Angle: Importance on Elemental Analysis of Asteroid Eros (433); An Investigation into Solar Wind Depletion of Sulfur in Troilite; Photometric Behaviour Dependent on Solar Phase Angle and Physical Characteristics of Binary Near-Earth-Asteroid (65803) 1996 GT; Spectroscopic Observations of Asteroid 4 Vesta from 1.9 to 3.5 micron: Evidence of Hydrated and/or Hydroxylated Minerals; Multi-Wavelength Observations of Asteroid 2100 Ra-Shalom: Visible, Infrared, and Thermal Spectroscopy Results; New Peculiarities of Cometary Outburst Activity; Preliminary Shape Modeling for the Asteroid (25143) Itokawa, AMICA of Hayabusa Mission; Scientific Capability of MINERVA Rover in Hayabusa Asteroid Mission; Characteristics and Current Status of Near Infrared Spectrometer for Hayabusa Mission; Sampling Strategy and Curation Plan of Hayabusa Asteroid Sample Return Mission; Visible/Near-Infrared Spectral Properties of MUSES C Target Asteroid 25143 Itokawa; Calibration of the NEAR XRS Solar Monitor; Modeling Mosaic Degradation of X-Ray Measurements of 433 Eros by NEAR-Shoemaker; Scattered Light Remediation and Recalibration of near Sheomaker s NIS Global Dataaset at 433 Eros; Evaluation of Preparation and Measuring Techniques for Interplanetary Dust Particles for the MIDAS Experiment on Rosetta; Chiron: a Proposed Remote Sensing Prompt Gamma Ray Activation Analysis Instrument for a Nuclear Powered Prometheus Mission;From Present Surveying to Future Prospecting of the Asteroid Belt; Asteroid Physical Properties Probe Microgravity Testing of a Surface Sampling System for Sample Return from Small Solar System Bodies;and Penetrator Coring Apparatus for Cometary Surfaces.
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Asteroid surface materials - Mineralogical characterizations and cosmological implications
NASA Technical Reports Server (NTRS)
Gaffey, M. J.; Mccord, T. B.
1977-01-01
The theoretical basis for the interpretation of diagnostic spectral features is examined and previous characterizations of asteroid surface materials are considered. A summary is provided of results reported by Gaffey and McCord (1977) who have utilized the most sophisticated interpretive techniques available to interpret the spectral reflectance data of about 65 asteroids for mineralogic and petrologic information. Cosmological implications related to the study of asteroid surface materials are also considered, taking into account source bodies for the meteorites, postaccretionary thermal history, significant factors of asteroid thermal history, and the Apollo and Amor asteroids. It is found that the asteroids exhibit surface materials made up of assemblages of meteoritic minerals. The relative abundance of meteorite types reaching the earth's surface is very different from the population of mineralogic types on asteroid surfaces. The earth-crossing or -approaching asteroids apparently derive from a restricted source region or population which is very strongly depleted in the C2-like assemblages that dominate the belt as a whole.
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Compositional differences between meteorites and near-Earth asteroids.
Vernazza, P; Binzel, R P; Thomas, C A; DeMeo, F E; Bus, S J; Rivkin, A S; Tokunaga, A T
2008-08-14
Understanding the nature and origin of the asteroid population in Earth's vicinity (near-Earth asteroids, and its subset of potentially hazardous asteroids) is a matter of both scientific interest and practical importance. It is generally expected that the compositions of the asteroids that are most likely to hit Earth should reflect those of the most common meteorites. Here we report that most near-Earth asteroids (including the potentially hazardous subset) have spectral properties quantitatively similar to the class of meteorites known as LL chondrites. The prominent Flora family in the inner part of the asteroid belt shares the same spectral properties, suggesting that it is a dominant source of near-Earth asteroids. The observed similarity of near-Earth asteroids to LL chondrites is, however, surprising, as this meteorite class is relatively rare ( approximately 8 per cent of all meteorite falls). One possible explanation is the role of a size-dependent process, such as the Yarkovsky effect, in transporting material from the main belt.
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How diverse is the asteroid belt?
NASA Technical Reports Server (NTRS)
Burbine, Thomas H.; Bell, Jeffrey F.
1993-01-01
For approximately twenty years, many different asteroid taxonomies, which used many different observational data sets, have been developed to try to group asteroids into classes that contain members with similar spectral characteristics. However, to understand the structure of the asteroid belt, the resulting classes are only useful if they are grouping together asteroids with somewhat similar mineralogies and thermal histories. Until recently, these taxonomies have focused on spectral reflectance data from 0.3 to 1.1 microns and visual albedo. But in the last five years, observational data sets (e.g., 0.8 to 2.5 microns spectra, CCD spectra, 3 microns spectra, and radar albedos) for a small number of asteroids were compiled that can give a better mineralogical interpretation, but whose use in asteroid taxonomy was relatively limited. Analyses of these 'supplementary' data sets show that most asteroid classes contain members with different compositions and/or thermal histories. To understand the diversity of the asteroid belt, the number of objects with these observations must be expanded and used in the next generation of taxonomies.
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The Steward Observatory asteroid relational database
NASA Technical Reports Server (NTRS)
Sykes, Mark V.; Alvarezdelcastillo, Elizabeth M.
1992-01-01
The Steward Observatory Asteroid Relational Database (SOARD) was created as a flexible tool for undertaking studies of asteroid populations and sub-populations, to probe the biases intrinsic to asteroid databases, to ascertain the completeness of data pertaining to specific problems, to aid in the development of observational programs, and to develop pedagogical materials. To date SOARD has compiled an extensive list of data available on asteroids and made it accessible through a single menu-driven database program. Users may obtain tailored lists of asteroid properties for any subset of asteroids or output files which are suitable for plotting spectral data on individual asteroids. A browse capability allows the user to explore the contents of any data file. SOARD offers, also, an asteroid bibliography containing about 13,000 references. The program has online help as well as user and programmer documentation manuals. SOARD continues to provide data to fulfill requests by members of the astronomical community and will continue to grow as data is added to the database and new features are added to the program.
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Origin of Martian Moons from Binary Asteroid Dissociation
NASA Technical Reports Server (NTRS)
Landis, Geoffrey A.; Lyons, Valerie J. (Technical Monitor)
2001-01-01
The origin of the Martian moons Deimos and Phobos is controversial. A common hypothesis for their origin is that they are captured asteroids, but the moons show no signs of having been heated by passage through a (hypothetical) thick martian atmosphere, and the mechanism by which an asteroid in solar orbit could shed sufficient orbital energy to be captured into Mars orbit has not been previously elucidated. Since the discovery by the space probe Galileo that the asteroid Ida has a moon 'Dactyl', a significant number of asteroids have been discovered to have smaller asteroids in orbit about them. The existence of asteroid moons provides a mechanism for the capture of the Martian moons (and the small moons of the outer planets). When a binary asteroid makes a close approach to a planet, tidal forces can strip the moon from the asteroid. Depending on the phasing, either or both can then be captured. Clearly, the same process can be used to explain the origin of any of the small moons in the solar system.
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Detection of ice and organics on an asteroidal surface.
Rivkin, Andrew S; Emery, Joshua P
2010-04-29
Recent observations, including the discovery in typical asteroidal orbits of objects with cometary characteristics (main-belt comets, or MBCs), have blurred the line between comets and asteroids, although so far neither ice nor organic material has been detected on the surface of an asteroid or directly proven to be an asteroidal constituent. Here we report the spectroscopic detection of water ice and organic material on the asteroid 24 Themis, a detection that has been independently confirmed. 24 Themis belongs to the same dynamical family as three of the five known MBCs, and the presence of ice on 24 Themis is strong evidence that it also is present in the MBCs. We conclude that water ice is more common on asteroids than was previously thought and may be widespread in asteroidal interiors at much smaller heliocentric distances than was previously expected.
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Meteorite spectroscopy and characterization of asteroid surface materials
NASA Technical Reports Server (NTRS)
Gaffey, Michael J.
1991-01-01
The analysis of visible and near-infrared reflectance spectra is the primary means to determine surface mineralogy and petrology of individual asteroids. These individual studies provide the data to investigate the broader relationships between the asteroids and meteorites and between asteroids at different heliocentric distances. The main purpose is to improve the understanding of the origin, evolution, and inter-relationships of the asteroids; of their relationships to the meteorites; and of the processes active and the conditions present in the early inner solar system. Empirical information from the study of asteroids and the meteorites is essential to the adequate development and testing of the theoretical models for the accretion of the terrestrial planets, and for their early post-accretionary evolution. The recent results are outined in the following sections: (1) asteroid igneous processes, and (2) spinel-bearing asteroids and the nebular compositional gradient.
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NASA Astrophysics Data System (ADS)
Pravec, P.
2013-05-01
From October 2012 we run our NEOSource project on the Danish 1.54-m telescope on La Silla. The primary aim of the project is to study non-gravitational processes in asteroids near the Earth and in their source regions in the main asteroidal belt. In my talk, I will give a brief overview of our current knowledge of the asteroidal non- gravitational processes and how we study them with photometric observations. I will talk especially about binary and paired asteroids that appear to be formed by rotational fission, about detecting the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) and BYORP (binary YORP) effects of anisotropic thermal emission from asteroids that change their spins and satellite orbits, and about non-principal axis rotators (the so called "tumblers") among the smallest, super-critically rotating asteroids with sizes < 100 meters.
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Simultaneous Mass Determination for Gravitationally Coupled Asteroids
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baer, James; Chesley, Steven R., E-mail: jimbaer1@earthlink.net
The conventional least-squares asteroid mass determination algorithm allows us to solve for the mass of a large subject asteroid that is perturbing the trajectory of a smaller test asteroid. However, this algorithm is necessarily a first approximation, ignoring the possibility that the subject asteroid may itself be perturbed by the test asteroid, or that the encounter’s precise geometry may be entangled with encounters involving other asteroids. After reviewing the conventional algorithm, we use it to calculate the masses of 30 main-belt asteroids. Compared to our previous results, we find new mass estimates for eight asteroids (11 Parthenope, 27 Euterpe, 51more » Neimausa, 76 Freia, 121 Hermione, 324 Bamberga, 476 Hedwig, and 532 Herculina) and significantly more precise estimates for six others (2 Pallas, 3 Juno, 4 Vesta, 9 Metis, 16 Psyche, and 88 Thisbe). However, we also find that the conventional algorithm yields questionable results in several gravitationally coupled cases. To address such cases, we describe a new algorithm that allows the epoch state vectors of the subject asteroids to be included as solve-for parameters, allowing for the simultaneous solution of the masses and epoch state vectors of multiple subject and test asteroids. We then apply this algorithm to the same 30 main-belt asteroids and conclude that mass determinations resulting from current and future high-precision astrometric sources (such as Gaia ) should conduct a thorough search for possible gravitational couplings and account for their effects.« less
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High-Resolution Imaging of the Multiphase Interstellar Thick Disk in Two Edge-On Spiral Galaxies
NASA Astrophysics Data System (ADS)
Howk, J. Christopher; Rueff, K.
2009-01-01
We present broadband and narrow-band images, acquired from Hubble Space Telescope WFPC2 and WIYN 3.5 m telescope respectively, of two edge-on spiral galaxies, NGC 4302 and NGC 4013. These high-resolution images (BVI + H-alpha) provide a detailed view of the thick disk interstellar medium (ISM) in these galaxies. Both galaxies show prominent extraplanar dust-bearing clouds viewed in absorption against the background stellar light. Individual clouds are found to z 2 kpc in each galaxy. These clouds each contain >10^4 to >10^5 solar masses of gas. Both galaxies have extraplanar diffuse ionized gas (DIG), as seen in our H-alpha images and earlier work. In addition to the DIG, discrete H II regions are found at heights up to 1 kpc from both galaxies. We compare the morphologies of the dusty clouds with the DIG in these galaxies and discuss the relationship between these components of the thick disk ISM.
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Mark Left by First Dig at Phoenix Site
NASA Technical Reports Server (NTRS)
2008-01-01
The hole in the ground produced by the first Robotic Arm dig at the landing site of NASA's Phoenix Mars Mission appears to the right of the three largest rocks near the center of this image. The hole is the width of the scoop on the end of the arm, about 9 centimeters (3.5 inches). It resulted from a practice dig during the mission's seventh Martian day, or sol 7 (June 1, 2008). The lander's Surface Stereo Imager took this image later that sol. The image is in approximately true color, produced by combining exposures taken through different filters. The green band at upper left is a portion where imaging data was incomplete in for one of the filters. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver. -
Ellwood, Elizabeth R; Kimberly, Paul; Guralnick, Robert; Flemons, Paul; Love, Kevin; Ellis, Shari; Allen, Julie M; Best, Jason H; Carter, Richard; Chagnoux, Simon; Costello, Robert; Denslow, Michael W; Dunckel, Betty A; Ferriter, Meghan M; Gilbert, Edward E; Goforth, Christine; Groom, Quentin; Krimmel, Erica R; LaFrance, Raphael; Martinec, Joann Lacey; Miller, Andrew N; Minnaert-Grote, Jamie; Nash, Thomas; Oboyski, Peter; Paul, Deborah L; Pearson, Katelin D; Pentcheff, N Dean; Roberts, Mari A; Seltzer, Carrie E; Soltis, Pamela S; Stephens, Rhiannon; Sweeney, Patrick W; von Konrat, Matt; Wall, Adam; Wetzer, Regina; Zimmerman, Charles; Mast, Austin R
2018-02-01
The digitization of biocollections is a critical task with direct implications for the global community who use the data for research and education. Recent innovations to involve citizen scientists in digitization increase awareness of the value of biodiversity specimens; advance science, technology, engineering, and math literacy; and build sustainability for digitization. In support of these activities, we launched the first global citizen-science event focused on the digitization of biodiversity specimens: Worldwide Engagement for Digitizing Biocollections (WeDigBio). During the inaugural 2015 event, 21 sites hosted events where citizen scientists transcribed specimen labels via online platforms (DigiVol, Les Herbonautes, Notes from Nature, the Smithsonian Institution's Transcription Center, and Symbiota). Many citizen scientists also contributed off-site. In total, thousands of citizen scientists around the world completed over 50,000 transcription tasks. Here, we present the process of organizing an international citizen-science event, an analysis of the event's effectiveness, and future directions-content now foundational to the growing WeDigBio event.
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Kim, Daeyeon; Alvarez, Mar; Lechuga, Laura M
2017-01-01
Animals explore their environment to encounter suitable food resources. Despite its vital importance, this behavior puts individuals at risk by consuming limited internal energy during locomotion. We have developed a novel assay to investigate how food-search behavior is organized in Drosophila melanogaster larvae dwelling in hydrogels mimicking their natural habitat. We define three main behavioral modes: resting at the gel’s surface, digging while feeding near the surface, and apneic dives. In unstimulated conditions, larvae spend most of their time digging. By contrast, deep and long exploratory dives are promoted by olfactory stimulations. Hypoxia and chemical repellents impair diving. We report remarkable differences in the dig-and-dive behavior of D. melanogaster and the fruit-pest D. suzukii. The present paradigm offers an opportunity to study how sensory and physiological cues are integrated to balance the limitations of dwelling in imperfect environmental conditions and the risks associated with searching for potentially more favorable conditions. PMID:28871963
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Kim, Daeyeon; Alvarez, Mar; Lechuga, Laura M; Louis, Matthieu
2017-09-05
Animals explore their environment to encounter suitable food resources. Despite its vital importance, this behavior puts individuals at risk by consuming limited internal energy during locomotion. We have developed a novel assay to investigate how food-search behavior is organized in Drosophila melanogaster larvae dwelling in hydrogels mimicking their natural habitat. We define three main behavioral modes: resting at the gel's surface, digging while feeding near the surface, and apneic dives. In unstimulated conditions, larvae spend most of their time digging. By contrast, deep and long exploratory dives are promoted by olfactory stimulations. Hypoxia and chemical repellents impair diving. We report remarkable differences in the dig-and-dive behavior of D. melanogaster and the fruit-pest D. suzukii . The present paradigm offers an opportunity to study how sensory and physiological cues are integrated to balance the limitations of dwelling in imperfect environmental conditions and the risks associated with searching for potentially more favorable conditions.
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AIDA: Asteroid Impact & Deflection Assessment
NASA Astrophysics Data System (ADS)
Cheng, Andrew; Michel, Patrick; Ulamec, Stephan; Reed, Cheryl; Galvez, Andres; Carnelli, Ian
On Feb. 15, 2013, an exceptionally close approach to Earth by the small asteroid 2012 DA14 was eagerly awaited by observers, but another small asteroid impacted Earth over Chelyabinsk, Russia the same day without warning, releasing several hundred kilotons TNT of energy and injuring over 1500 people. These dramatic events remind us of the needs to discover hazardous asteroids and to learn how to mitigate them. The AIDA mission is the first demonstration of a mitigation technique to protect the Earth from a potential asteroid impact, by performing a spacecraft kinetic impact on an asteroid to deflect it from its trajectory. We will provide an update on the status of parallel AIDA mission studies supported by ESA and NASA. AIDA is an international collaboration consisting of two independent but mutually supporting missions, one of which is the asteroid kinetic impactor, and the other is the characterization spacecraft which will orbit the asteroid system to monitor the deflection experiment and measure the results. These two missions are the NASA Double Asteroid Redirection Test (DART), which is the kinetic impactor, and the European Space Agency's Asteroid Impact Monitoring (AIM) mission, which is the characterization spacecraft. The target of the AIDA mission will be a binary asteroid, in which DART will target the secondary, smaller member in order to deflect the binary orbit. The resulting period change can be measured to within 10% by ground-based observations. The asteroid deflection will be measured to higher accuracy, and additional results of the DART impact, like the impact crater, will be studied in great detail by the AIM mission. AIDA will return vital data to determine the momentum transfer efficiency of the kinetic impact and key physical properties of the target asteroid. The two mission components of AIDA, DART and AIM, are each independently valuable, but when combined they provide a greatly increased knowledge return. The AIDA mission will combine US and European space experience and expertise to address an international problem, the asteroid impact hazard. AIDA will also be a valuable precursor to human spaceflight to an asteroid, as it would return unique information on an asteroid's strength and internal structure and would be particularly relevant to a human mission for asteroid mitigation. AIDA will furthermore return fundamental new science data on impact cratering, surface properties and interior structure. AIDA will target the binary Near-Earth asteroid Didymos with two independently launched spacecraft, with the deflection experiment to occur in October, 2022.
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Near-earth asteroids - Possible sources from reflectance spectroscopy
NASA Technical Reports Server (NTRS)
Mcfadden, L. A.; Gaffey, M. J.; Mccord, T. B.
1985-01-01
The diversity of reflectance spectra noted among near-earth asteroids that were compared with selected asteroids, planets and satellites to determine possible source regions is indicative of different mineralogical composition and, accordingly, of more than one source region. Spectral signatures that are similar to those of main belt asteroids support models deriving some of these asteroids from the 5:2 Kirkwood gap and the Flora family, by way of gravitational perturbations. The differences in composition found between near-earth asteroids and planetary and satellite surfaces are in keeping with theoretical arguments that such bodies should not be sources. While some near-earth asteroids furnish portions of the earth's meteorite flux, other sources must also contribute.
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The breakup of a main-belt asteroid 450 thousand years ago.
Nesvorný, David; Vokrouhlický, David; Bottke, William F
2006-06-09
Collisions in the asteroid belt frequently lead to catastrophic breakups, where more than half of the target's mass is ejected into space. Several dozen large asteroids have been disrupted by impacts over the past several billion years. These impact events have produced groups of fragments with similar orbits called asteroid families. Here we report the discovery of a very young asteroid family around the object 1270 Datura. Our work takes advantage of a method for identification of recent breakups in the asteroid belt using catalogs of osculating (i.e., instantaneous) asteroid orbits. The very young families show up in these catalogs as clusters in a five-dimensional space of osculating orbital elements.
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Accessibility of near-Earth asteroids, 1990
NASA Technical Reports Server (NTRS)
Hulkower, Neal D.; Child, Jack B.
1991-01-01
Previous research which analyzed the accessibility of all known near-Earth asteroids is updated. Since then, many new near-Earth asteroids have been discovered, and 1928 DB, the most accessible asteroid at that time, has been recovered. Many of these recently discovered near-Earth asteroids have promising orbital characteristics. In addition to accessibility (as defined by minimum global delta v), ideal rendezvous opportunities are identified.
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CCD scanning for asteroids and comets
NASA Technical Reports Server (NTRS)
Gehrels, T.; Mcmillan, R. S.
1986-01-01
A change coupled device (CCD) is used in a scanning mode to find new asteroids and recover known asteroids and comet nuclei. Current scientific programs include recovery of asteroids and comet nuclei requested by the Minor Planet Center (MPC), discovery of new asteroids in the main belt and of unusual orbital types, and follow-up astrometry of selected new asteroids discovered. The routine six sigma limiting visual magnitude is 19.6 and slightly more than a square degree is scanned three times every 90 minutes of observing time during the fortnight centered on New Moon. Semiautomatic software for detection of moving objects is in routine use; angular speeds as low as 11.0 arcseconds per hour were distinguished from the effects of the Earth's atmosphere on the field of view. A typical set of three 29-minute scans near the opposition point along the ecliptic typically nets at least 5 new main-belt asteroids down to magnitude 19.6. In 18 observing runs (months) 43 asteroids were recovered, astrometric and photometric data on 59 new asteroids were reported, 10 new asteroids with orbital elements were consolidated, and photometry and positions of 22 comets were reported.
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NASA Astrophysics Data System (ADS)
This document is dedicated first to the criteria used to select a candidate asteroid. It contains the known characteristics of this asteroid as well as the assumptions made about it. It ends with a preliminary study of other possible more favorable candidates which might be found in the near future. Special attention is paid to the possible existence of Earth-Sun Trojan asteroids. Second, there is a description of the current state of our limited knowledge about the asteroids, and of the instruments and techniques being used to improve this knowledge. The contribution to asteroid research which can be expected from the new instruments already in space or due to be launched in this decade is then discussed. The last part of this document gives a description of different ways of improving our knowledge about the asteroids, both quantitatively and qualitatively. A proposal requiring reasonable financing and manpower to improve asteroid research is presented. It is believed that the implementation of such a program would have a dramatic effect on asteroid research. For example, a significant increase in both the rate of discovery of asteroids and their corresponding orbital parameters would be obtained. This program could be fully operational 3 years after its implementation.
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Studies of asteroids, comets, and Jupiter's outer satellites
NASA Technical Reports Server (NTRS)
Bowell, Edward
1988-01-01
The work comprises observational, theoretical, and computational research on asteroids, together with a smaller effort concerning the astrometry of comets and Jupiter's satellites JVI through JXIII. Two principal areas of research, centering on astrometry and photometry, are interrelated in their aim to study the overall structure of the asteroid belt and the physical and orbital properties of individual asteroids. About 2000 accurate photographic positions of asteroids and comets, including a number from the Lowell, Palomar, and Goethe-Link archival plate collections, the last of which was donated to us last winter by Indiana University were measured and published. Charge coupled device (CCD) astrometry of 36 faint targets was undertaken, including 4 comets; JVI, JVII, JVIII, JLX, JXI, and JXII; and 26 asteroids, most of which are Earth-approachers. A deep, bias-correctable asteroid survey (LUKAS), the aim of which is to determine the true spatial distribution of asteroids down to subkilometer diameters was started. A series of eight plates at the UK Schmidt telescope that contain images of asteroids as faint as V approximately 22 mag was obtained. Analysis of microdensitometric scans of two plates has shown that about 98 percent of the asteroid images could be identified completely automatically.
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Storyboard GALILEO CRUISE SCIENCE OPPORTUNITIES describes asteroid encounters
NASA Technical Reports Server (NTRS)
1989-01-01
Storyboard with mosaicked image of an asteroid and entitled GALILEO CRUISE SCIENCE OPPORTUNITIES describes asteroid objectives. These objectives include: first asteroid encounter; surface geology, composition size, shape, mass; and relation of primitive bodies to meteorites.
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Earth-approaching asteroid streams
NASA Astrophysics Data System (ADS)
Drummond, J. D.
1991-01-01
Three association patterns have been noted among 139 earth-approaching asteroids on the basis of current orbital similarity; these asteroid streams, consisting of two groups of five members and one of four, can be matched to three of the four meteorite-producing fireball streams determined by Halliday et al. (1990). If the asteroid streams are true nonrandom associations, the opportunity arises for studies of an 'exploded' asteroid in the near-earth environment. Near-earth asteroid-search projects are encouraged to search the mean orbit of the present streams in order to discover additional association members.
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Depletion of the Outer Asteroid Belt
Liou; Malhotra
1997-01-17
During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.
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NASA Technical Reports Server (NTRS)
Lebofsky, L. A.; Jones, T. D.; Herbert, F.
1989-01-01
Asteroids appear in light of telescopic and meteority studies to be the most accessible repositories of early solar system history available. In the cooler regions of the outer asteroid belt, apparently unaffected by severe heating, the C, P, and D populations appear to harbor significant inventories of volatiles; the larger primordial belt population may have had an even greater percentage of volatile-rich, low-albedo asteroids, constituting a potent asteroid for veneering early terrestrial planet atmospheres. The volatile-rich asteroids contain carbon, structurally bound and adsorbed water, as well as remnants of interstellar material predating the solar system.
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Depletion of the Outer Asteroid Belt
NASA Technical Reports Server (NTRS)
Liou, Jer-Chyi; Malhotra, Renu
1997-01-01
During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.
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Star Formation Driven Outflows In Edge-On Spiral Galaxies Based on HST/ACS Observations
NASA Astrophysics Data System (ADS)
Rossa, Joern; Dahlem, M.; Dettmar, R.; van der Marel, R. P.
2007-12-01
We present new results on extraplanar diffuse ionized gas (eDIG) in four late-type, actively star-forming edge-on spirals. The high spatial resolution narrowband imaging observations were obtained with ACS on-board HST. Our H-alpha observations reveal a multitude of structures on both small and large scales. Whereas all four galaxies have been studied with ground-based telescopes before, here the small scale structure of the extended emission line gas is presented for the very first time at a spatial resolution of 0.05", corresponding to 5 pc at the mean distance to our galaxies. The eDIG morphology is very different for all four targets, as a result of their different star formation activity and galaxy mass. There is a very smooth DIG morphology observed in two of the galaxies (NGC4634 and NGC5775), whereas the other two (NGC4700 and NGC7090) show a much more complex morphology with intricate filaments, bubbles and supershells. We discuss how the morphology of the eDIG, in particular the break-up of diffuse emission into filaments in galaxy halos, depends on physical parameters such as galaxy mass and SF activity and other tracers as well as the galactic environment. Support for proposal 10416 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
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Kinetic analysis of manure pyrolysis and combustion processes.
Fernandez-Lopez, M; Pedrosa-Castro, G J; Valverde, J L; Sanchez-Silva, L
2016-12-01
Due to the depletion of fossil fuel reserves and the environmental issues derived from their use, biomass seems to be an excellent source of renewable energy. In this work, the kinetics of the pyrolysis and combustion of three different biomass waste samples (two dairy manure samples before (Pre) and after (Dig R) anaerobic digestion and one swine manure sample (SW)) was studied by means of thermogravimetric analysis. In this work, three iso-conversional methods (Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS)) were compared with the Coats-Redfern method. The E a values of devolatilization stages were in the range of 152-170kJ/mol, 148-178kJ/mol and 156-209kJ/mol for samples Pre, Dig R and SW, respectively. Concerning combustion process, char oxidation stages showed lower E a values than that obtained for the combustion devolatilization stage, being in the range of 140-175kJ/mol, 178-199kJ/mol and 122-144kJ/mol for samples Pre, Dig R and SW, respectively. These results were practically the same for samples Pre and Dig R, which means that the kinetics of the thermochemical processes were not affected by anaerobic digestion. Finally, the distributed activation energy model (DAEM) and the pseudo-multi component stage model (PMSM) were applied to predict the weight loss curves of pyrolysis and combustion. DAEM was the best model that fitted the experimental data. Copyright © 2016 Elsevier Ltd. All rights reserved.
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A remarkable oxygen-rich asymptotic giant branch variable in the Sagittarius Dwarf Irregular Galaxy
NASA Astrophysics Data System (ADS)
Whitelock, Patricia A.; Menzies, John W.; Feast, Michael W.; Marigo, Paola
2018-01-01
We report and discuss JHKS photometry for Sgr dIG, a very metal-deficient galaxy in the Local Group, obtained over 3.5 years with the Infrared Survey Facility in South Africa. Three large amplitude asymptotic giant branch variables are identified. One is an oxygen-rich star that has a pulsation period of 950 d, which was until recently undergoing hot bottom burning, with Mbol ∼ -6.7. It is surprising to find a variable of this sort in Sgr dIG, given their rarity in other dwarf irregulars. Despite its long period the star is relatively blue and is fainter, at all wavelengths shorter than 4.5 μm, than anticipated from period-luminosity relations that describe hot bottom burning stars. A comparison with models suggests it had a main-sequence mass Mi ∼ 5 M⊙ and that it is now near the end of its asymptotic giant branch evolution. The other two periodic variables are carbon stars with periods of 670 and 503 d (Mbol ∼ -5.7 and -5.3). They are very similar to other such stars found on the asymptotic giant branch of metal-deficient Local Group galaxies and a comparison with models suggests Mi ∼ 3 M⊙. We compare the number of asymptotic giant branch variables in Sgr dIG to those in NGC 6822 and IC 1613, and suggest that the differences may be due to the high specific star formation rate and low metallicity of Sgr dIG.
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DigBody®: A new 3D modeling tool for nasal virtual surgery.
Burgos, M A; Sanmiguel-Rojas, E; Singh, Narinder; Esteban-Ortega, F
2018-07-01
Recent studies have demonstrated that a significant number of surgical procedures for nasal airway obstruction (NAO) have a high rate of surgical failure. In part, this problem is due to the lack of reliable objective clinical parameters to aid surgeons during preoperative planning. Modeling tools that allow virtual surgery to be performed do exist, but all require direct manipulation of computed tomography (CT) or magnetic resonance imaging (MRI) data. Specialists in Rhinology have criticized these tools for their complex user interface, and have requested more intuitive, user-friendly and powerful software to make virtual surgery more accessible and realistic. In this paper we present a new virtual surgery software tool, DigBody ® . This new surgery module is integrated into the computational fluid dynamics (CFD) program MeComLand ® , which was developed exclusively to analyze nasal airflow. DigBody ® works directly with a 3D nasal model that mimics real surgery. Furthermore, this surgery module permits direct assessment of the operated cavity following virtual surgery by CFD simulation. The effectiveness of DigBody ® has been demonstrated by real surgery on two patients based on prior virtual operation results. Both subjects experienced excellent surgical outcomes with no residual nasal obstruction. This tool has great potential to aid surgeons in modeling potential surgical maneuvers, minimizing complications, and being confident that patients will receive optimal postoperative outcomes, validated by personalized CFD testing. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Recovering and Mining Asteroids with a Gas-Sealed Enclosure
NASA Astrophysics Data System (ADS)
Jenniskens, P.; Damer, B.; Norkus, R.; Pilotz, S.; Grigsby, B.; Adams, C.; Blair, B. R.
2015-01-01
The internal structure of weakly consolidated rubble piles and primitive asteroids can be studied closer to home, and such asteroids can be mined, if it is possible to create a gas-sealed enclosure around the asteroid.
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Dynamical passage to approximate equilibrium shapes for spinning, gravitating rubble asteroids
NASA Astrophysics Data System (ADS)
Sharma, Ishan; Jenkins, James T.; Burns, Joseph A.
2009-03-01
Many asteroids are thought to be particle aggregates held together principally by self-gravity. Here we study — for static and dynamical situations — the equilibrium shapes of spinning asteroids that are permitted for rubble piles. As in the case of spinning fluid masses, not all shapes are compatible with a granular rheology. We take the asteroid to always be an ellipsoid with an interior modeled as a rigid-plastic, cohesion-less material with a Drucker-Prager yield criterion. Using an approximate volume-averaged procedure, based on the classical method of moments, we investigate the dynamical process by which such objects may achieve equilibrium. We first collapse our dynamical approach to its statical limit to derive regions in spin-shape parameter space that allow equilibrium solutions to exist. At present, only a graphical illustration of these solutions for a prolate ellipsoid following the Drucker-Prager failure law is available [Sharma, I., Jenkins, J.T., Burns, J.A., 2005a. Bull. Am. Astron. Soc. 37, 643; Sharma, I., Jenkins, J.T., Burns, J.A., 2005b. Equilibrium shapes of ellipsoidal soil asteroids. In: García-Rojo, R., Hermann, H.J., McNamara, S. (Eds.), Proceedings of the 5th International Conference on Micromechanics of Granular Media, vol. 1. A.A. Balkema, UK; Holsapple, K.A., 2007. Icarus 187, 500-509]. Here, we obtain the equilibrium landscapes for general triaxial ellipsoids, as well as provide the requisite governing formulae. In addition, we demonstrate that it may be possible to better interpret the results of Richardson et al. [Richardson, D.C., Elankumaran, P., Sanderson, R.E., 2005. Icarus 173, 349-361] within the context of a Drucker-Prager material. The graphical result for prolate ellipsoids in the static limit is the same as those of Holsapple [Holsapple, K.A., 2007. Icarus 187, 500-509] because, when worked out, his final equations will match ours. This is because, though the formalisms to reach these expressions differ, in statics, at the lowest level of approximation, volume-averaging and the approach of Holsapple [Holsapple, K.A., 2007. Icarus 187, 500-509] coincide. We note that the approach applied here was obtained independently [Sharma, I., Jenkins, J.T., Burns, J.A., 2003. Bull. Am. Astron. Soc. 35, 1034; Sharma, I., 2004. Rotational Dynamics of Deformable Ellipsoids with Applications to Asteroids. Ph.D. thesis, Cornell University] and it provides a general, though approximate, framework that is amenable to systematic improvements and is flexible enough to incorporate the dynamical effects of a changing shape, different rheologies and complex rotational histories. To demonstrate our technique, we investigate the non-equilibrium dynamics of rigid-plastic, spinning, prolate asteroids to examine the simultaneous histories of shape and spin rate for rubble piles. We have succeeded in recovering most results of Richardson et al. [Richardson, D.C., Elankumaran, P., Sanderson, R.E., 2005. Icarus 173, 349-361], who obtained equilibrium shapes by studying numerically the passage into equilibrium of aggregates containing discrete, interacting, frictionless, spherical particles. Our mainly analytical approach aids in understanding and quantifying previous numerical simulations.
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The Steward Observatory asteroid relational database
NASA Technical Reports Server (NTRS)
Sykes, Mark V.; Alvarezdelcastillo, Elizabeth M.
1991-01-01
The Steward Observatory Asteroid Relational Database (SOARD) was created as a flexible tool for undertaking studies of asteroid populations and sub-populations, to probe the biases intrinsic to asteroid databases, to ascertain the completeness of data pertaining to specific problems, to aid in the development of observational programs, and to develop pedagogical materials. To date, SOARD has compiled an extensive list of data available on asteroids and made it accessible through a single menu-driven database program. Users may obtain tailored lists of asteroid properties for any subset of asteroids or output files which are suitable for plotting spectral data on individual asteroids. The program has online help as well as user and programmer documentation manuals. The SOARD already has provided data to fulfill requests by members of the astronomical community. The SOARD continues to grow as data is added to the database and new features are added to the program.
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Identification of a primordial asteroid family constrains the original planetesimal population.
Delbo', Marco; Walsh, Kevin; Bolin, Bryce; Avdellidou, Chrysa; Morbidelli, Alessandro
2017-09-08
A quarter of known asteroids is associated with more than 100 distinct asteroid families, meaning that these asteroids originate as impact fragments from the family parent bodies. The determination of which asteroids of the remaining population are members of undiscovered families, or accreted as planetesimals from the protoplanetary disk, would constrain a critical phase of planetary formation by unveiling the unknown planetesimal size distribution. We discovered a 4-billion-year-old asteroid family extending across the entire inner part of the main belt whose members include most of the dark asteroids previously unlinked to families. This allows us to identify some original planetesimals, which are all larger than 35 kilometers, supporting the view of asteroids being born big. Their number matches the known distinct meteorite parent bodies. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
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Shape and spin of asteroid 967 Helionape
NASA Astrophysics Data System (ADS)
Apostolovska, G.; Kostov, A.; Donchev, Z.; Bebekovska, E. Vchkova; Kuzmanovska, O.
2018-04-01
Knowledge of the spin and shape parameters of the asteroids is very important for understanding of the conditions during the creation of our planetary system and formation of asteroid populations. The main belt asteroid and Flora family member 967 Helionape was observed during five apparitions. The observations were made at the Bulgarian National Astronomical Observatory (BNAO) Rozhen, since March 2006 to March 2016. Lihtcurve inversion method (Kaasalainen et al. (2001)), applied on 12 relative lightcurves obtained at various geometric conditions of the asteroid, reveals the spin vector, the sense of rotation and the preliminary shape model of the asteroid. Our aim is to contribute in increasing the set of asteroids with known spin and shape parameters. This could be done with dense lightcurves, obtained during small number of apparitions, in combination with sparse data produced by photometric asteroid surveys such as the Gaia satellite (Hanush (2011)).
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NASA Technical Reports Server (NTRS)
Cintala, M. J.; Durda, D. D.; Housen, K. R.
2005-01-01
Other than remote-sensing and spacecraft-derived data, the only information that exists regarding the physical and chemical properties of asteroids is that inferred through calculations, numerical simulations, extrapolation of experiments, and meteorite studies. Our understanding of the dynamics of accretion of planetesimals, collisional disruption of asteroids, and the macroscopic, shock-induced modification of the surfaces of such small objects is also, for the most part, founded on similar inferences. While considerable strides have been made in improving the state of asteroid science, too many unknowns remain to assert that we understand the parameters necessary for the more practical problem of deflecting an asteroid or asteroid pair on an Earth-intersecting trajectory. Many of these deficiencies could be reduced or eliminated by intentionally deorbiting an asteroidal satellite and monitoring the resulting collision between it and the primary asteroid, a capability that is well within the limitations of current technology.
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Workshop on Oxygen in Asteroids and Meteorites
NASA Technical Reports Server (NTRS)
2005-01-01
Contents include the following: Constraints on the detection of solar nebula's oxidation state through asteroid observation. Oxidation/Reduction Processes in Primitive Achondrites. Low-Temperature Chemical Processing on Asteroids. On the Formation Location of Asteroids and Meteorites. The Spectral Properties of Angritic Basalts. Correlation Between Chemical and Oxygen Isotopic Compositions in Chondrites. Effect of In-Situ Aqueous Alteration on Thermal Model Heat Budgets. Oxidation-Reduction in Meteorites: The Case of High-Ni Irons. Ureilite Atmospherics: Coming up for Air on a Parent Body. High Temperature Effects Including Oxygen Fugacity, in Pre-Planetary and Planetary Meteorites and Asteroids. Oxygen Isotopic Variation of Asteroidal Materials. High-Temperature Chemical Processing on Asteroids: An Oxygen Isotope Perspective. Oxygen Isotopes and Origin of Opaque Assemblages from the Ningqiang Carbonaceous Chondrite. Water Distribution in the Asteroid Belt. Comparative Planetary Mineralogy: V Systematics in Planetary Pyroxenes and fo 2 Estimates for Basalts from Vesta.
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ASIME 2016 White Paper: Answers to Questions from the Asteroid Miners
NASA Astrophysics Data System (ADS)
Galache, Jl; Graps, A. L.; Asime 2016 Contributors, 30
2017-09-01
The aim of the Asteroid Science Intersections with In-Space Mine Engineering (ASIME) 2016 conference on September 21-22, 2016 in Luxembourg City was to provide an environment for the detailed discussion of the specific properties of asteroids, with the engineering needs of space missions that utilise asteroids. The ASIME 2016 Conference produced a layered record of discussions from the asteroid scientists and the asteroid miners to understand each other's key concerns and to address key scientific questions from the asteroid mining companies: Planetary Resources, Deep Space Industries and TransAstra. These Questions were the focus of the two-day conference, were addressed by scientists inside and outside of the ASIME 2016 Conference and were the focus of this White Paper. The answers in this White Paper point to the Science Knowledge Gaps (SKGs) for advancing the asteroid in-space resource utilisation domain.
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Assessment of the Gaussian Covariance Approximation over an Earth-Asteroid Encounter Period
NASA Technical Reports Server (NTRS)
Mattern, Daniel
2017-01-01
In assessing the risk an asteroid may pose to the Earth, the asteroids state is often predicted for many years, often decades. Only by accounting for the asteroids initial state uncertainty can a measure of the risk be calculated. With the asteroids state uncertainty growing as a function of the initial velocity uncertainty, orbit velocity at the last state update, and the time from the last update to the epoch of interest, the asteroids position uncertainties can grow to many times the size of the Earth when propagated to the encounter risk corridor. This paper examines the merits of propagating the asteroids state covariance as an analytical matrix. The results of this study help to bound the efficacy of applying different metrics for assessing the risk an asteroid poses to the Earth. Additionally, this work identifies a criterion for when different covariance propagation methods are needed to continue predictions after an Earth-encounter period.