JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papenbrock, Thomas

2014-05-16

The grant “JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei ” (DOE DE-FG02-06ER41407) ran from 02/01/2006 thru 12/31/2013. JUSTIPEN is a venue for international collaboration between U.S.-based and Japanese scientists who share an interest in theory of rare isotopes. Since its inception JUSTIPEN has supported many visitors, fostered collaborations between physicists in the U.S. and Japan, and enabled them to deepen our understanding of exotic nuclei and their role in cosmos.

Enhanced airglow at Titan

NASA Astrophysics Data System (ADS)

Royer, Emilie; Esposito, Larry; Wahlund, Jan-Erik

2016-06-01

The Cassini Ultraviolet Imaging Spectrograph (UVIS) instrument made thousand of observations of Titan since its arrival in the Saturnian system in 2004, but only few of them have been analyzed yet. Using the imaging capability of UVIS combined to a big data analytics approach, we have been able to uncover an unexpected pattern in this observations: on several occasions the Titan airglow exhibits an enhanced brightness by approximately a factor of 2, generally combined with a lower altitude of the airglow emission peak. These events typically last from 10 to 30 minutes and are followed and preceded by an airglow of regular and expected level of brightness and altitude. Observations made by the Cassini Plasma Spectrometer (CAPS) instrument onboard Cassini allowed us to correlate the enhanced airglow observed on T-32 with an electron burst. The timing of the burst and the level of energetic electrons (1 keV) observed by CAPS correspond to a brighter and lower than typical airglow displayed on the UVIS data. Furthermore, during T-32 Titan was inside the Saturn's magnetosheath and thus more subject to bombardment by energetic particles. However, our analysis demonstrates that the presence of Titan inside the magnetosheath is not a necessary condition for the production of an enhanced airglow, as we detected other similar events while Titan was within Saturn's magnetosphere. The study presented here aims to a better understanding of the interactions of Titan's upper atmosphere with its direct environment.

Titan's Methane Hydrological Cycle: Detection of Seasonal Change

NASA Astrophysics Data System (ADS)

Schaller, E. L.; Brown, M. E.; Roe, H. G.

2007-08-01

We have acquired whole disk spectra of Titan on over 100 nights with IRTF/SpeX during the 2006-2007 Titan season. The data encompass the spectral range of 0.8 to 2.4 microns at a resolution of 375. These disk- integrated spectra allow us to determine Titan's total fractional cloud coverage and altitudes of clouds present. The near lack of tropospheric cloud activity in these spectra is in sharp contrast to nearly every spectrum taken from 1995-1999 with UKIRT by Griffith et al. (1998 & 2000) who found rapidly varying clouds covering 0.5-9% of Titan's disk. The differences in these two similar datasets indicate a striking seasonal change in the behavior of Titan's clouds. Adaptive optics observations from Keck and Gemini also show markedly decreased cloud activity in the late southern summer era compared with the period surrounding southern summer solstice (October 2002). Observations of the latitudes, magnitudes, altitudes, and frequencies of Titan's clouds as Titan moves toward southern autumnal equinox in 2009 will help elucidate when and how Titan's methane hydrological cycle changes with season.

The Exploration of Titan and the Saturnian System

NASA Astrophysics Data System (ADS)

Coustenis, Athena

The exploration of the outer solar system and in particular of the giant planets and their environments is an on-going process with the Cassini spacecraft currently around Saturn, the Juno mission to Jupiter preparing to depart and two large future space missions planned to launch in the 2020-2025 time frame for the Jupiter system and its satellites (Europa and Ganymede) on the one hand, and the Saturnian system and Titan on the other hand [1,2]. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Following the Voyager flyby in 1980, Titan has been intensely studied from the ground-based large telescopes (such as the Keck or the VLT) and by artificial satellites (such as the Infrared Space Observatory and the Hubble Space Telescope) for the past three decades. Prior to Cassini-Huygens, Titan's atmospheric composition was thus known to us from the Voyager missions and also through the explorations by the ISO. Our perception of Titan had thus greatly been enhanced accordingly, but many questions remained as to the nature of the haze surrounding the satellite and the composition of the surface. The recent revelations by the Cassini-Huygens mission have managed to surprise us with many discoveries [3-8] and have yet to reveal more of the interesting aspects of the satellite. The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on

U.S. Military Aviation Mishaps In Japan and Okinawan Political Controversy

DTIC Science & Technology

2015-12-01

political controversy over U.S. bases in Japan, the American presence in the island country has proven its strategic advantages for the United States...CONTEMPORARY OKINAWAN HISTORY Located approximately 400 miles south of mainland Japan, Okinawa is the largest island in the Ryukyu Island chain. In the 17th...century, Okinawa served as tributary state to both China and Japan. Commerce brought additional influences to the island , helping to shape a

Abundance and Temperature Variations in Titan's Atmosphere as Revealed by ALMA

NASA Astrophysics Data System (ADS)

Thelen, A. E.; Nixon, C. A.; Chanover, N.; Molter, E.; Cordiner, M. A.; Serigano, J., IV; Irwin, P. G.; Charnley, S. B.; Teanby, N. A.

2016-12-01

Photochemistry in Titan's atmosphere produces a wealth of organic molecular species through the dissociation of it's main constituents: N2 and CH4. Chemical species including hydrocarbons (CXHY) and nitriles (CXHY[CN]Z) exhibit latitudinal variations in abundance as observed by Cassini, attributed to atmospheric circulation and Titan's seasonal cycle. Flux calibration images of Titan taken by the Atacama Large Millimeter/Submillimeter Array (ALMA) with beam sizes smaller than Titan's angular diameter ( 0.7'') allow for measurements of rotational transition lines in spatially resolved regions of Titan's disk. We present nitrile abundance profiles and temperature measurements derived from CO lines obtained by ALMA in 2014, as Titan transitioned into northern summer. Vertical profiles in Titan's lower/middle atmosphere were retrieved by modeling high resolution ALMA spectra using the Non-linear Optimal Estimator for MultivariatE Spectral analySIS (NEMESIS) radiative transfer code. We present a comparison of the abundance variations of chemical species to measurements made using Cassini data. Temperature profiles derived from CO lines are compared to Cassini Composite Infrared Spectrometer temperature fields. The techniques presented here will allow us to determine temporal changes in Titan's atmospheric chemical composition after the end of the Cassini mission by utilizing high resolution ALMA data. Comparisons of chemical species with strong abundance enhancements over the poles will inform our knowledge of chemical lifetimes in Titan's atmosphere, and allow us to observe the important changes in production and circulation of numerous organic molecules which are attributed to Titan's seasons.

Titan Global Map - June 2015

NASA Image and Video Library

2015-10-09

This global digital map of Saturn's moon Titan was created using images taken by NASA's Cassini spacecraft's imaging science subsystem (ISS). The map was produced in June 2015 using data collected through Cassini's flyby on April 7, 2014, known as "T100." The images were taken using a filter centered at 938 nanometers, allowing researchers to examine variations in albedo (or inherent brightness) across the surface of Titan. Because of the scattering of light by Titan's dense atmosphere, no topographic shading is visible in these images. The map is an equidistant projection and has a scale of 2.5 miles (4 kilometers) per pixel. Actual resolution varies greatly across the map, with the best coverage (close to the map scale) along the equator near the center of the map at 180 degrees west longitude. The lowest resolution coverage can be seen in the northern mid-latitudes on the sub-Saturn hemisphere. Mapping coverage in the northern polar region has greatly improved since the previous version of this map in 2011 (see PIA14908). Large dark areas, now known to be liquid-hydrocarbon-filled lakes and seas, have since been documented at high latitudes. Titan's north pole was not well illuminated early in Cassini's mission, because it was winter in the northern hemisphere when the spacecraft arrived at Saturn. Cassini has been better able to observe northern latitudes in more recent years due to seasonal changes in solar illumination. This map is an update to the previous versions released in April 2011 and February 2009 (see PIA11149). Data from the past four years (the most recent data in the map is from April 2014) has completely filled in missing data in the north polar region and replaces the earlier imagery of the Xanadu region with higher quality data. A data gap of about 3 to 5 percent of Titan's surface still remains, located in the northern mid-latitudes on the sub-Saturn hemisphere of Titan. The uniform gray area in the northern hemisphere indicates a gap in the

US hospital payment adjustments for innovative technology lag behind those in Germany, France, and Japan.

PubMed

Hernandez, John; Machacz, Susanne F; Robinson, James C

2015-02-01

Medicare pioneered add-on payments to facilitate the adoption of innovative technologies under its hospital prospective payment system. US policy makers are now experimenting with broader value-based payment initiatives, but these have not been adjusted for innovation. This article examines the structure, processes, and experience with Medicare's hospital new technology add-on payment program since its inception in 2001 and compares it with analogous payment systems in Germany, France, and Japan. Between 2001 and 2015 CMS approved nineteen of fifty-three applications for the new technology add-on payment program. We found that the program resulted in $201.7 million in Medicare payments in fiscal years 2002-13-less than half the level anticipated by Congress and only 34 percent of the amount projected by CMS. The US program approved considerably fewer innovative technologies, compared to analogous technology payment mechanisms in Germany, France and Japan. We conclude that it is important to adjust payments for new medical innovations within prospective and value-based payment systems explicitly as well as implicitly. The most straightforward method to use in adjusting value-based payments is for the insurer to retrospectively adjust spending targets to account for the cost of new technologies. If CMS made such retrospective adjustments, it would not financially penalize hospitals for adopting beneficial innovations. Project HOPE—The People-to-People Health Foundation, Inc.

Pluto's Implications for a Snowball Titan

NASA Astrophysics Data System (ADS)

Wong, M.; Yung, Y. L.; Gladstone, R.

2013-12-01

The recent Cassini-Huygens Mission to the Saturnian system provides compelling evidence that the present state of Titan's dense atmosphere is unsustainable over the age of the Solar System. Instead, for most of the time Titan's atmosphere must have existed in a collapsed snowball state, characterized by a cold surface and a thin atmosphere, much like those of present-day Pluto and Triton. We will briefly review how the present Titan atmosphere exists due to a sensitive coupling between photochemistry, radiation, and dynamics. This delicate 'house of cards' must have collapsed in the past when it ran out of CH4 or when the sun was dimmer. We will investigate how the rate of organic synthesis on Snowball Titan differs from that of contemporary Titan. The forthcoming New Horizons Mission to Pluto and the Kuiper Belt may allow us to gain insights into the fine balance and the evolutionary history of certain planetary atmospheres. In particular, the high SNR solar occultations planned for observation with the Alice UV spectrograph on New Horizons are expected to yield abundance profiles of important hydrocarbons and nitriles in Pluto's atmosphere, providing detailed constraints for photochemical models such as those considered here.

Integration of PanDA workload management system with Titan supercomputer at OLCF

NASA Astrophysics Data System (ADS)

De, K.; Klimentov, A.; Oleynik, D.; Panitkin, S.; Petrosyan, A.; Schovancova, J.; Vaniachine, A.; Wenaus, T.

2015-12-01

The PanDA (Production and Distributed Analysis) workload management system (WMS) was developed to meet the scale and complexity of LHC distributed computing for the ATLAS experiment. While PanDA currently distributes jobs to more than 100,000 cores at well over 100 Grid sites, the future LHC data taking runs will require more resources than Grid computing can possibly provide. To alleviate these challenges, ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). The current approach utilizes a modified PanDA pilot framework for job submission to Titan's batch queues and local data management, with light-weight MPI wrappers to run single threaded workloads in parallel on Titan's multicore worker nodes. It also gives PanDA new capability to collect, in real time, information about unused worker nodes on Titan, which allows precise definition of the size and duration of jobs submitted to Titan according to available free resources. This capability significantly reduces PanDA job wait time while improving Titan's utilization efficiency. This implementation was tested with a variety of Monte-Carlo workloads on Titan and is being tested on several other supercomputing platforms. Notice: This manuscript has been authored, by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

JPL-20170811-CASSINf-0001a-A World Unveiled Cassini at TItan

NASA Image and Video Library

2017-08-11

A look at the Cassini-Huygens mission's discoveries at Saturn's moon Titan and a description of how flybys of Titan allowed the mission to change to new orbits repeatedly without wasting fuel. Featuring Linda Spilker, Cassini Project Scientist, JPL; Jonathan Lunine, Cassini Titan Scientist, Cornell University; and Elizabeth "Zibi" Turtle, Cassini Imaging Team, John Hopkins Applied Physics Laboratory.

Exobiology and the solar system: the Cassini mission to Titan.

PubMed

Raulin, F; Gautier, D; Ip, W H

1984-01-01

The recent Voyager mission and the simulation experiments in the laboratory suggest that a complex nitrogen-organic chemistry is occuring at the periphery of Titan. Thus, this satellite of Saturn appears as a privileged place in the solar system for the study of extraterrestrial organic chemistry which can be considered as part of Exobiology. Projects of space mission relating to Titan are already under investigation, in particular with the "CASSINI" proposal. The CASSINI project is a combination of a Saturn orbiter and a Titan probe mission. Such a mission would allow the first study "in situ" of a complex extraterrestrial organic chemistry in atmospheric phase.

Titan AVIATR - Aerial Vehicle for In Situ and Airborne Titan Reconnaissance

NASA Astrophysics Data System (ADS)

Kattenhorn, Simon A.; Barnes, J. W.; McKay, C. P.; Lemke, L.; Beyer, R. A.; Radebaugh, J.; Adamkovics, M.; Atkinson, D. H.; Burr, D. M.; Colaprete, T.; Foch, R.; Le Mouélic, S.; Merrison, J.; Mitchell, J.; Rodriguez, S.; Schaller, E.

2010-10-01

Titan AVIATR - Aerial Vehicle for In Situ and Airborne Titan Reconnaissance - is a small (120 kg), nuclear-powered Titan airplane in the Discovery/New Frontiers class based on the concept of Lemke (2008 IPPW). The scientific goals of the mission are designed around the unique flexibility offered by an airborne platform: to explore Titan's diversity of surface landforms, processes, and compositions, as well as to study and measure the atmospheric circulation, aerosols, and humidity. AVIATR would address and surpass many of the science goals of hot-air balloons in Titan flagship studies. The strawman instrument payload is narrowly focused on the stated scientific objectives. The optical remote sensing suite comprises three instruments - an off-nadir high-resolution 2-micron camera, a horizon-looking 5-micron imager, and a 1-6 micron pushbroom near-infrared spectrometer. The in situ instruments include atmospheric structure, a methane humidity sensor, and a raindrop detector. An airplane has operational advantages over a balloon. Its piloted nature allows a go-to capability to image locations of interest in real time, thereby allowing for directed exploration of many features of primary geologic interest: Titan's sand dunes, mountains, craters, channels, and lakes. Subsequent imaging can capture changes in these features during the primary mission. AVIATR can fly predesigned routes, building up large context mosaics of areas of interest before swooping down to low altitude to acquire high-resolution images at 30-cm spatial sampling, similar to that of HiRISE at Mars. The elevation flexibility of the airplane allows us to acquire atmospheric profiles as a function of altitude at any desired location. Although limited by the direct-to-Earth downlink bandwidth, the total scientific data return from AVIATR will be >40 times that returned from Huygens. To maximize the science per bit, novel data storage and downlink techniques will be employed, including lossy compression

US-Japan Collaborative Research on Evaluation Tools and Methods Comparison of Evaluation Tools and Methods Used in the United States (U.S.) and Japan.

DOT National Transportation Integrated Search

2016-04-01

The United States (U.S.) and Japan have similar transportation challenges, and share a common belief that cooperative systems can deliver significant societal benefits for road users, especially in terms of safer, more energy-efficient, and environme...

Japan.

PubMed

1989-02-01

Japan consists of 3900 islands and lies off the east coast of Asia. Even though Japan is one of the most densely populated nations in the world, its growth rate has stabilized at .5%. 94% of all children go to senior high school and almost 90% finish. Responsibility for the sick, aged, and infirmed is changing from the family and private sector to government. Japan was founded in 600 BC and its 1st capital was in Nara (710-1867). The Portuguese, the 1st Westerners to make contact with Japan in 1542, opened trade which lasted until the mid 17th century. US Navy Commodore Matthew Perry forced Japan to reopen in 1854. Following wars with China and Russia in the late 1800s and early 1900s respectively, Japan took part in World Wars I and II. In between these wars Japan invaded Manchuria and China. The US dropped an atomic bomb on Hiroshima and Nagasaki and the Japanese surrendered in September, 1945 ending World War II (WWII). Following, WWII, the Allied Powers guided Japan's establishment as a nonthreatening nation and a democratic parliamentary government (a constitutional monarchy) with a limited defense force. Japan remains one of the most politically stable of all postwar democracies. The Liberal Democratic Party's Noboru Takeshita became prime minister in 1987. Japan has limited natural resources and only 19% of the land is arable. Japanese ingenuity and skill combine to produce one of the highest per hectare crop yields in the world. Japan is a major economic power, and its and the US economies are becoming more interdependent. Its exports, making up only 13% of the gross national product, mainly go to Canada and the US. Many in the US are concerned, however, with the trade deficit with Japan and are seeking ways to make trade more equitable. Japan wishes to maintain good relations with its Asian neighbors and other nations. The US and Japan enjoy a strong, productive relationship.

Titan!

NASA Astrophysics Data System (ADS)

Matson, Dennis L.

2010-05-01

Cassini-Huygens achieved Saturnian orbit on July 1, 2004. The first order of business was the safe delivery of the Huygens atmospheric probe to Titan that took place on January 14, 2005. Huygens descended under parachute obtaining observations all the way down to a safe landing. It revealed Titan for the first time. Stunning are the similarities between Titan and the Earth. Viewing the lakes and seas, the fluvial terrain, the sand dunes and other features through the hazy, nitrogen atmosphere, brings to mind the geological processes that created analogous features on the Earth. On Titan frozen water plays the geological role of rock; liquid methane takes the role of terrestrial water. The atmospheres of both Earth and Titan are predominately nitrogen gas. Titan's atmosphere contains 1.5% methane and no oxygen. The surface pressure on Titan is 1.5 times the Earth's. There are aerosol layers and clouds that come and go. Now, as Saturn proceeds along its solar orbit, the seasons are changing. The effects upon the transport of methane are starting to be seen. A large lake in the South Polar Region seems to be filling more as winter onsets. Will the size and number of the lakes in the South grow during winter? Will the northern lakes and seas diminish or dry up as northern summer progresses? How will the atmospheric circulation change? Much work remains not only for Cassini but also for future missions. Titan has many different environments to explore. These require more capable instruments and in situ probes. This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space Administration.

"Different than Us": Othering, Orientalism, and US Middle School Students' Discourses on Japan

ERIC Educational Resources Information Center

Inokuchi, Hiromitsu; Nozaki, Yoshiko

2005-01-01

This study critically examines the discourses of Japan as employed by young people in the United States. In particular, it analyses the free writings of US middle school students that were collected at three schools with different community environments (rural, urban, and suburban). The study identifies the features and styles of the discourse(s)…

Physician scarcity is a predictor of further scarcity in US, and a predictor of concentration in Japan.

PubMed

Matsumoto, Masatoshi; Inoue, Kazuo; Bowman, Robert; Noguchi, Satomi; Kajii, Eiji

2010-05-01

To assess the effects of geographic diffusion of physicians from medically oversupplied toward undersupplied areas driven by economic competition among physicians and political interventions in Japan and US. A quantitative evaluation of physician workforce changes at the community level between 1980 and 2005, using municipality-based (Japan) and county-based (US) census data. The overall number of physicians per 100,000 population (physician-to-population ratio: PPR) increased from 130 to 203 in Japan and 158 to 234 in US. In this context, a higher proportion (30.1%) of the quintile communities with lowest PPRs in 1980 has further decreased their PPRs in US than in Japan (21.6% in 2005). In multivariate analysis low PPR was a positive predictor of PPR decrease in the US communities (odds ratio 1.26; 95% confidence interval 1.01-1.58), while it was a negative predictor in Japanese communities (0.69; 0.57-0.83). Physician scarcity is associated with further scarcity in US communities, while scarcity is associated with recovery from scarcity in Japanese communities. Competition-based physician diffusion strategies and various interventions to address the maldistribution of physicians apparently have not worked effectively in US compared with Japan. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Theoretical Calculations on Sediment Transport on Titan, and the Possible Production of Streamlined Forms

NASA Technical Reports Server (NTRS)

Burr, D. M.; Emery, J. P.; Lorenz, R. D.

2005-01-01

The Cassini Imaging Science System (ISS) has been returning images of Titan, along with other Saturnian satellites. Images taken through the 938 nm methane window see down to Titan's surface. One of the purposes of the Cassini mission is to investigate possible fluid cycling on Titan. Lemniscate features shown recently and radar evidence of surface flow prompted us to consider theoretically the creation by methane fluid flow of streamlined forms on Titan. This follows work by other groups in theoretical consideration of fluid motion on Titan's surface.

Seasonal Change in Titan's Cloud Activity Observed with IRTF/SpeX

NASA Astrophysics Data System (ADS)

Schaller, Emily L.; Brown, M. E.; Roe, H. G.

2006-09-01

We have acquired whole disk spectra of Titan on nineteen nights with IRTF/SpeX over a three-month period in the spring of 2006. The data encompass the spectral range of 0.8 to 2.4 microns at a resolution of 375. These disk-integrated spectra allow us to determine Titan's total fractional cloud coverage and altitudes of clouds present. We find that Titan had less than 0.15% fractional cloud coverage on all but one of the nineteen nights. The near lack of cloud activity in these spectra is in sharp contrast to nearly every spectrum taken from 1995-1999 with UKIRT by Griffith et al. (1998 & 2000) who found rapidly varying clouds covering 0.5% of Titan's disk. The differences in these two similar datasets indicate a striking seasonal change in the behavior of Titan's clouds. Observations of the latitudes, magnitudes, altitudes, and frequencies of Titan's clouds as Titan moves toward southern autumnal equinox in 2009 will help elucidate when and how Titan's methane hydrological cycle changes with season.

Japan.

PubMed

1987-02-01

Japan is composed of 4 main islands and more than 3900 smaller islands and has 317.7 persons/square kilometer. This makes it one of the most densely populated nations in the world. Religion is an important force in the life of the Japanese and most consider themselves Buddhists. Schooling is free through junior high but 90% of Japanese students complete high school. In fact, Japan enjoys one of the highest literacy rates in the world. There are over 178 newspapers and 3500 magazines published in Japan and the number of new book titles issued each year is greater than that in the US. Since WW1, Japan expanded its influence in Asia and its holdings in the Pacific. However, as a direct result of WW2, Japan lost all of its overseas possessions and was able to retain only its own islands. Since 1952, Japan has been ruled by conservative governments which cooperate closely with the West. Great economic growth has come since the post-treaty period. Japan as a constitutional monarchy operates within the framework of a constitution which became effective in May 1947. Executive power is vested in a cabinet which includes the prime minister and the ministers of state. Japan is one of the most politically stable of the postwar democracies and the Liberal Democratic Party is representative of Japanese moderate conservatism. The economy of Japan is strong and growing. With few resources, there is only 19% of Japanese land suitable for cultivation. Its exports earn only about 19% of the country's gross national product. More than 59 million workers comprise Japan's labor force, 40% of whom are women. Japan and the US are strongly linked trading partners and after Canada, Japan is the largest trading partner of the US. Foreign policy since 1952 has fostered close cooperation with the West and Japan is vitally interested in good relations with its neighbors. Relations with the Soviet Union are not close although Japan is attempting to improve the situation. US policy is based on

Strategies for Detecting Biological Molecules on Titan.

PubMed

Neish, Catherine D; Lorenz, Ralph D; Turtle, Elizabeth P; Barnes, Jason W; Trainer, Melissa G; Stiles, Bryan; Kirk, Randolph; Hibbitts, Charles A; Malaska, Michael J

2018-05-02

Saturn's moon Titan has all the ingredients needed to produce "life as we know it." When exposed to liquid water, organic molecules analogous to those found on Titan produce a range of biomolecules such as amino acids. Titan thus provides a natural laboratory for studying the products of prebiotic chemistry. In this work, we examine the ideal locales to search for evidence of, or progression toward, life on Titan. We determine that the best sites to identify biological molecules are deposits of impact melt on the floors of large, fresh impact craters, specifically Sinlap, Selk, and Menrva craters. We find that it is not possible to identify biomolecules on Titan through remote sensing, but rather through in situ measurements capable of identifying a wide range of biological molecules. Given the nonuniformity of impact melt exposures on the floor of a weathered impact crater, the ideal lander would be capable of precision targeting. This would allow it to identify the locations of fresh impact melt deposits, and/or sites where the melt deposits have been exposed through erosion or mass wasting. Determining the extent of prebiotic chemistry within these melt deposits would help us to understand how life could originate on a world very different from Earth. Key Words: Titan-Prebiotic chemistry-Solar system exploration-Impact processes-Volcanism. Astrobiology xx, xxx-xxx.

This is Commercial Titan Inc.

NASA Astrophysics Data System (ADS)

Van Rensselaer, F. L.; Slovikoski, R. D.; Abels, T. C.

Out of a quarter-century heritage of eminently successful expendable launch vehicle history with the U.S. government, a commercial launch services enterprise which challenges the corporation as well as the competition has been launched within the Martin Marietta Corporation. This paper is an inside look at the philosophy, structure, and success of the new subsidiary, Commercial Titan Inc., which is taking on its U.S. and foreign rocket-making competitors to win a share of the international communication satellite market as well as the U.S. government commercial launch services market.

This is Commercial Titan, Inc

NASA Astrophysics Data System (ADS)

van Rensselaer, F. L.; Slovikoski, R. D.; Abels, T. C.

1989-10-01

Out of a quarter-century heritage of eminently successful expendable launch vehicle history with the U.S government, a commercial launch services enterprise which challenges the corporation as well as the competition has been launched within the Martin Marietta Corporation. This paper is an inside look at the philosophy, structure, and success of the new subsidiary, Commercial Titan, Inc., which is taking on its U.S. and foreign rocket-making competitors to win a share of the international communication satellite market as well as the U.S. government commercial launch services market.

Formation Mechanisms for Dunes Observed on Titan

NASA Astrophysics Data System (ADS)

Vinson, Alec; Hays, C. C.; Lopes-Gautier, R. M.; Mitchell, K. L.; Diniega, S.; Farr, T. G.

2013-01-01

The Cassini spacecraft has discovered massive dune fields on Saturn’s largest moon, Titan. The dunes were observed with the Cassini Synthetic Aperture Radar Imaging (SARS) instrument. The radar instrument operates at a frequency of 13.78 GHz, corresponding to a wavelength 2.2 cm. The resolution for the images examined are ~ 1 pixel = 175 m (varies from image to image). These dunes, or at least what’s visible to radar, through the thick nitrogen Titan atmosphere, seem to be almost exclusively longitudinal dunes (with crests forming parallel to prevailing wind directions). Many unanswered questions remain about these dunes. One goal of this project is to attempt to calculate the heights of these dunes, which has not yet been systematically attempted. We will use radar parallax analyses to calculate the height of the dunes. The Cassini radar determines position based on how long the radar wave took to return to the spacecraft, making an assumption that the surface is a perfect sphere. With changes in height, the time return for radar will change, distorting the image. Looking at these distortions (specifically, the shortening or elongation of the side of a dune) and knowing the inclination angle, we can determine height or depth. We will also use this same method with radar images of the Namib dunes, in southwest Africa, as an Earth analog, to test and determine how accurate our method is. This approach should give useful information on the morphology of the dunes on Titan. Knowing more about the morphology of the dunes can teach us more about the dune’s composition and formation mechanisms.

A Survey of Titan Balloon Concepts and Technology Status

NASA Technical Reports Server (NTRS)

Hall, Jeffery L.

2011-01-01

This paper surveys the options for, and technology status of, balloon vehicles to explore Saturn's moon Titan. A significant amount of Titan balloon concept thinking and technology development has been performed in recent years, particularly following the spectacular results from the descent and landing of the Huygens probe and remote sensing observations by the Cassini spacecraft. There is widespread recognition that a balloon vehicle on the next Titan mission could provide an outstanding and unmatched capability for in situ exploration on a global scale. The rich variety of revealed science targets has combined with a highly favorable Titan flight environment to yield a wide diversity of proposed balloon concepts. The paper presents a conceptual framework for thinking about balloon vehicle design choices and uses it to analyze various Titan options. The result is a list of recommended Titan balloon vehicle concepts that could perform a variety of science missions, along with their projected performance metrics. Recent technology developments for these balloon concepts are discussed to provide context for an assessment of outstanding risk areas and technological maturity. The paper concludes with suggestions for technology investments needed to achieve flight readiness.

ALMA observations of Titan : Vertical and spatial distribution of nitriles

NASA Astrophysics Data System (ADS)

Moreno, R.; Lellouch, E.; Vinatier, S.; Gurwell, M.; Moullet, A.; Lara, L. M.; Hidayat, T.

2015-10-01

We report submm observations of Titan performed with the ALMA interferometer centered at the rotational frequencies of HCN(4-3) and HNC(4-3), i.e. 354 and 362 GHz. These measurements yielded disk-resolved emission spectra of Titan with an angular resolution of ~0.47''. Titan's angular surface diameter was 0.77''. Data were acquired in summer 2012 near the greatest eastern and western elongations of Titan at a spectral resolution of 122 kHz (λ/d λ = 3106). We have obtained maps of several nitriles present in Titan' stratosphere: HCN, HC3N, CH3CN, HNC, C2H5CNand other weak lines (isotopes, vibrationnally excited lines).We will present radiative transfer analysis of the spectra acquired. With the combination of all these detected rotational lines, we will constrain the atmospheric temperature, the spatial and vertical distribution of these species, as well as isotopic ratios. Moreover, Doppler lineshift measurements will enable us to constrain the zonal wind flow in the upper atmosphere.

Aerocapture Systems Analysis for a Titan Mission

NASA Technical Reports Server (NTRS)

Lockwood, Mary K.; Queen, Eric M.; Way, David W.; Powell, Richard W.; Edquist, Karl; Starr, Brett W.; Hollis, Brian R.; Zoby, E. Vincent; Hrinda, Glenn A.; Bailey, Robert W.

2006-01-01

Performance projections for aerocapture show a vehicle mass savings of between 40 and 80%, dependent on destination, for an aerocapture vehicle compared to an all-propulsive chemical vehicle. In addition aerocapture is applicable to multiple planetary exploration destinations of interest to NASA. The 2001 NASA In-Space Propulsion Program (ISP) technology prioritization effort identified aerocapture as one of the top three propulsion technologies for solar system exploration missions. An additional finding was that aerocapture needed a better system definition and that supporting technology gaps needed to be identified. Consequently, the ISP program sponsored an aerocapture systems analysis effort that was completed in 2002. The focus of the effort was on aerocapture at Titan with a rigid aeroshell system. Titan was selected as the initial destination for the study due to potential interest in a follow-on mission to Cassini/Huygens. Aerocapture is feasible, and the performance is adequate, for the Titan mission and it can deliver 2.4 times more mass to Titan than an all-propulsive system for the same launch vehicle.

From Titan's chemistry and exobiology to Titan's astrobiology

NASA Astrophysics Data System (ADS)

Raulin, François

2015-04-01

When the IDS proposal « Titan's chemistry and exobiology » was submitted to ESA 25 years ago, in the frame of what will become the Cassini-Huygens mission, Titan was already seen as a quite interesting planetary object in the solar system for Exobiology. Several organic compounds of prebiotic interest were identified in its atmosphere, which was thus was expected to be chemically very active, especially in term of organic processes. Atmospheric aerosols seemed to play a key role in this chemistry. Moreover, the presence of an internal aqueous ocean, compatible with life was suspected. A few years later, when astrobiology was (re)invented, Titan became one of the most interesting planetary target for this new (but very similar to exobiology) field. With the Cassini-Huygens mission, the exo/astrobiological interest of Titan has become more and more important. However, the mission has been providing a vision of Titan quite different from what it was supposed. Its atmospheric organic chemistry is very complex and starts in much higher zones than it was believed before, involving high molecular weight species in the ionosphere. Titan's surface appears to be far from homogeneous: instead of been covered by a global methane-ethane ocean, it is very diversified, with dunes, lakes, bright and dark areas, impact and volcanic craters with potential cryovolcanic activity. These various geological areas are continuously feeded by atmospheric aerosols, which represent an important step in the complexity of Titan's organic chemistry, but probably not the final one. Indeed, after being deposited on the surface, in the potential cryovolvanic zones, these particles may react with water ice and form compounds of exo/astrobiological interest, such as amino acids, purine and pyrimidine bases. Moreover, The Cassini-Huygens data strongly support the potential presence of an internal water ocean, which becomes less and less hypothetical and of great interest for exobiology. These

77 FR 55230 - Japan Lessons-Learned Project Directorate Interim Staff Guidance JLD-ISG-2012-01; Compliance With...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0068] Japan Lessons-Learned Project Directorate Interim... Commission (NRC). ACTION: Japan Lessons-Learned Project Directorate interim staff guidance; issuance. SUMMARY...-Learned Project Directorate Interim Staff Guidance (JLD-ISG), JLD-ISG-2012-01, ``Compliance with Order EA...

Poster 12: Nitrile and Hydrocarbon Spatial Abundance Variations in Titan's Atmosphere

NASA Astrophysics Data System (ADS)

Thelen, Alexander E.; Nixon, Conor A.; Molter, Edward; Serigano, Joseph; Cordiner, Martin A.; Charnley, Steven B.; Teanby, Nick; Chanover, Nancy

2016-06-01

Many minor constituents of Titan's atmosphere exhibit latitudinal variations in abundance as a result of atmospheric circulation, photochemical production and subsequent destruction throughout Titan's seasonal cycle [1,2]. Species with observed spatial abundance variations include hydrocarbons - such as CH3CCH - and nitriles - HCN, HC3N, CH3CN, and C2H5CN - as found by Cassini [3,4]. Recent calibration images of Titan taken by the Atacama Large Millimeter/Submillimeter Array (ALMA) allow for measurements of rotational transition lines of these species in spatially resolved regions of Titan's disk [5]. Abundance profiles in Titan's lower/middle atmosphere are retrieved by modeling high resolution ALMA spectra using the Non-linear Optimal Estimator for MultivariatE Spectral analySIS (NEMESIS) radiative transfer code [6]. We present continuous abundance profiles for various species in Titan's atmosphere obtained from ALMA data in 2014. These species show polar abundance enhancements which can be compared to studies using Cassini data [7]. Measurements in the mesosphere will constrain molecular photochemical and dynamical models, while temporal variations inform our knowledge of chemical lifetimes for the large inventory of organic species produced in Titan's atmosphere. The synthesis of the ALMA and Cassini datasets thus allow us to observe the important changes in production and circulation of numerous trace components of Titan's atmosphere, which are attributed to Titan's seasons.

Sagan Lecture : Exploring Titan, An Earth-like Organic Paradise

NASA Astrophysics Data System (ADS)

Lorenz, R. D.

2007-12-01

Saturn's giant moon Titan has been called many things - 'The Mars of the Outer Solar System', 'A Fiercely-Frozen Echo of the Early Earth', 'A Place Like Home'- indeed, 'The Whole ball of Wax'. These various appelations reflect the richness and bewildering complexity of this most fascinating world which bears comparisons with both the terrestrial planets as well as other icy satellites. Titan's thick but dynamic atmosphere sculpts its surface with tidal winds and methane monsoons, and its climate has competing greenhouse and antigreenhouse effects as well as a seasonal polar haze structure analogous to the Earth's ozone hole. Titan is striking also in its massive organic inventory - its dunes and lakes make up an exposed carbon reservoir hundreds of times more massive than all of Earth's fossil fuels. At least part of this organic inventory has been processed by transient exposures to liquid water, in impact melt sheets and cryovolcanic flows (a scenario first pointed out by Thompson and Sagan in 1991). This aqueous chemical interaction is known from terrestrial laboratory experiments to yield amino acids, pyrimidines and other building blocks of living molecular systems. How far these chemical systems might evolve on geological, as opposed to laboratory, scales of space and time on Titan is completely unknown, but must surely be interesting to find out. The talk will review some of the surprising findings from Cassini-Huygens, their lessons for us here on Earth, and what future Titan exploration may tell us about the origins of worlds and the origins of life.

Radio Telescopes "Save the Day," Produce Data on Titan's Winds

NASA Astrophysics Data System (ADS)

2005-02-01

measurements were carried out and processed jointly by scientists from the NASA Jet Propulsion Laboratory (JPL, USA), and the Joint Institute for VLBI in Europe (JIVE, The Netherlands) working within an international Doppler Wind Experiment team. The GBT made the first detection of Huygens' radio signal during the descent, and gave flight controllers and scientists the first indication that the spacecraft's parachute had deployed and that it was "alive" after entering Titan's atmosphere. The radio-telescope measurements also indicated changes in Huygens' speed when it exchanged parachutes and when it landed on Titan's surface. The original plan for gauging Titan's winds called for measuring the Doppler shift in the probe's signal frequency both by Cassini and by ground-based radio telescopes in the U.S., Australia, Japan and China. Cassini was best positioned to gain information on the east-west component of the winds, and the ground-based telescopes were positioned to help learn about the north-south wind component. Unfortunately, the communications error lost all the wind data from Cassini. The VLBA The VLBA CREDIT: NRAO/AUI/NSF (Click on image for VLBA gallery) "I've never felt such exhilarating highs and dispiriting lows than those experienced when we first detected the signal from the GBT, indicating 'all's well,' and then discovering that we had no signal at the operations center, indicating 'all's lost.' The truth, as we have now determined, lies somewhat closer to the former than the latter." said Michael Bird of the University of Bonn. In addition to measuring the motion-generated frequency shift of Huygens' radio signal, radio telescopes also were used to make extremely precise measurements of the probe's position (to within three-quarters of a mile, or one kilometer) during its descent. This experiment used the VLBA antennas, along with others employing the technique of Very Long Baseline Interferometry (VLBI). Combination of the Doppler and VLBI data will

Selections from 2017: Discoveries in Titan's Atmosphere

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-12-01

Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.Carbon Chain Anions and the Growth of Complex Organic Molecules in Titans IonospherePublished July2017Main takeaway:Graphic depicting some of the chemical reactions taking place in Titans atmosphere, leading to the generation of organic haze particles. [ESA]In a recently published study led by Ravi Desai (University College London), scientists used data from the Cassini mission to identify negatively charged molecules known as carbon chain anions in the atmosphere of Saturns largest moon, Titan.Why its interesting:Carbon chain anions are the building blocks ofmore complex molecules, and Titans thick nitrogen and methane atmosphere mightmimic the atmosphere of earlyEarth. This first unambiguous detection of carbon chain anions in a planet-like atmosphere might therefore teach us about the conditions and chemical reactions that eventually led to the development of life on Earth. And ifwe can use Titan to learn about how complex molecules grow from these anion chains, we may be able to identify auniversal pathway towards the ingredients for life.What weve learned so far:Cassini measured fewer and fewer lower-mass anions the deeper in Titans ionosphere that it looked and at the same time,an increase in the number of precursors to larger aerosol molecules further down. This tradeoff strongly suggests that the anions are indeed involved in building up the more complex molecules, seeding their eventual growth into the complex organic haze of Titans lower atmosphere.CitationR. T. Desai et al 2017 ApJL 844 L18. doi:10.3847/2041-8213/aa7851

Future Exploration of Titan

NASA Astrophysics Data System (ADS)

Lorenz, R. D.; Titan Decadal Panel Collaboration

2001-11-01

Titan promises to be the Mars of the Outer Solar System - the focus of not only the broadest range of investigations in planetary science but also the focus of public attention. The reasons for exploring Titan are threefold: 1. Titan and Astrobiology : Titan ranks with Mars and Europa as a prime body for astrobiological study due to its abundant organics. Like Europa, it may well have a liquid water interior. 2. Titan - A world in its own right. Titan deserves study even only to put other satellites (its remarkably smaller Saturnian siblings, and its same-sized but volatile-poor Jovian counterparts) in context. The added dimension of an atmosphere makes Titan's origin and evolution particularly interesting. 3. Titan - an environmental laboratory for Earth. Titan will be an unrivalled place to investigate meteorological, oceanographical and other processes. Many of these (e.g. wave generation by wind) are only empirically parameterized - the very different physical parameters of the Titan environment will bring new insights to these phenomena. While Cassini-Huygens will dramatically boost our knowledge of Titan, it will likely only whet our appetite for more. The potential for prebiotic materials at various locations (in particular where liquid water has interacted with photochemical deposits) and the need to monitor Titan's meteorology favor future missions that may exploit Titan's unique thick-atmosphere, low-gravity environment - a mobile platform like an airship or helicopter, able to explore on global scales, but access the surface for in-situ chemical analysis and probe the interior by electromagnetic and seismic means. Such missions have dramatic potential to capture the public's imagination, on both sides of the Atlantic.

Titan Polar Maps - 2015

NASA Image and Video Library

2015-10-09

,400 meters) per pixel. The mean radius of Titan used for projection of these maps is 1,600 miles (2,575 kilometers). http://photojournal.jpl.nasa.gov/catalog/PIA19657

MR-2016 US-Japan Workshop on Magentic Reconnection Travel Support

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forest, Cary

The US-Japan workshop on Magnetic Reconnection (MR2016), was held in Napa California from March 7th through 11th, 2016. Details about the program, including invited speakers can be found here: (http://www.magneticreconnection.org/mr2016). Background: The MR Workshop is an international meeting that began in 2000 with its original focus on magnetic reconnection serving as a link between the research groups in US and Japan. Since then, the meeting has grown and is now recognized as one of the primary international workshops on magnetic reconnection. In its format, researchers from both the laboratory community and from the space research community have held 12 workshopsmore » bringing together the diverse researchers from the space and laboratory experimental fields. Plasma physics is the common language that ties together all scientists who study the waves, particle acceleration and heating, magnetic reconnection, dynamos, global and micro-stability of plasmas, magnetic turbulence and plasma’s transport problems. The meeting received $9,575 from the U.S. Dept. of Energy funding. This support was used to cover the registration fees ($575 per person) and accommodations for ten junior colleagues (graduate students and postdocs). Applications were solicited and then reviewed by the program committee based on recommendations from the applicants’ advisers.« less

Temperate Lakes Discovered on Titan

NASA Astrophysics Data System (ADS)

Vixie, Graham; Barnes, Jason W.; Jackson, Brian; Wilson, Paul

2012-04-01

We have discovered two temperate lakes on Titan using Cassini's Visual and Infrared Mapping Spectrometer (VIMS). Three key features help to identify these surface features as lakes: morphology, albedo, and specular reflection. The presence of lakes at the mid-latitudes mean liquid can accumulate and remain stable outside of the poles. We first identify a lake surface by looking for possible shorelines with a lacustrine morphology. Then, we apply a simple atmospheric correction that produces an approximate surface albedo. Next, we prepare cylindrical projection maps of the brightness of the sky as seen from any points on the surface to identify specular reflections. Our techniques can then be applied to other areas, such as Arrakis Planitia, to test for liquid. Currently, all the known lakes on Titan are concentrated at the poles. Lakes have been suggested in the tropic zone by Griffith et al. Our discovery of non-transient, temperate lakes has important implications for Titan's hydrologic cycle. Clouds have been recorded accumulating in the mid-latitudes and areas have been darkened by rainfall but later brightened after evaporation (Turtle et al. 2011). Stable temperate lakes would affect total rainfall, liquid accumulation, evaporation rates, and infiltration. Polaznik Macula (Figure 1) is a great candidate for lake filling, evaporation rates, and stability. References: Griffith, C., et al.: "Evidence for Lakes on Titan's Tropical Surface". AAS/Division for Planetary Sciences Meeting Abstracts #42, Vol. 42, pp. 1077, 2010. Turtle, E. P., et al.: "Rapid and Extensive Surface Changes Near Titan's Equator: Evidence of April Showers". Science, Vol. 331, pp. 1414-, 2011. Figure 1: Polaznik Macula is the large, dark area central to the figure. The encircled dark blue areas represent positively identified lake regions in the T66 flyby. The light blue areas represent lake candidates still under analysis. The green circle marks a non-lake surface feature enclosed by a

How sustainable is Japan's foreign aid policy? An analysis of Japan's official development assistance and funding for energy sector projects

NASA Astrophysics Data System (ADS)

Yamaguchi, Hideka

Japan has adopted a sustainable development strategy since the late 1980s in the effort to address social and environmental damages caused by past Japan-funded projects in partner nations. Even after about a decade and a half of the policy implementation, however, there are few reports which critically examine effects of the adoption of the idea of sustainable development. This dissertation evaluates Japan's foreign aid policy to determine the extent to which new revisions of aid policy have improved the environmental sustainability of the policy. This dissertation reviews the mainstream idea of sustainable development (also known as the sustainable development paradigm in this dissertation) to reveal the nature of the idea of sustainable development that Japan's foreign aid policy depends on. A literature review of two development discourses---modernization theory and ecological modernization theory---and three types of critiques against the sustainable development paradigm---focused on adverse impacts of modern science, globalization, and environmental overuse---reveals core logics of and problems with the sustainable development paradigm. Japan's foreign aid policy impacts on energy sector development in recipient countries is examined by means of a quantitative analysis and a qualitative analysis. Specifically, it examines the effect of Japan's ODA program over fifteen years that proposed to facilitate sustainable development in developing countries. Special emphasis is given to investigation of ODA disbursements in the energy sector and detailed case studies of several individual energy projects are performed. The dissertation discovers that the sustainable development paradigm guiding Japan's ODA has little capacity to accomplish its goals to bring about social and ecological improvement in developing countries. This dissertation finds three fundamental weaknesses in Japanese ODA policy on energy sector development as well as the sustainable development

Titan Submarines!

NASA Astrophysics Data System (ADS)

Oleson, S. R.; Lorenz, R. D.; Paul, M. V.; Hartwig, J. W.; Walsh, J. M.

2017-02-01

A NIAC Phase II submarine concept, dubbed 'Titan Turtle' for Saturn's moon Titan's northern sea, Ligea Mare. A design concept including science and operations is described for this -180°C liquid methane sea.

An international comparison of PPP in road projects and prospects for Japan

NASA Astrophysics Data System (ADS)

Onaka, Takafumi; Morichi, Sigeru; Inoue, Satoshi; Hibino, Naohiko

Japanese PFI Law was enacted in Japan in 1999. In these eleven years almost all PFI projects were for buildings, while the infrastructure projects were only about 5% in total. Regarding to the road projects that have been managed by the government, there are various bottlenecks for the implementation of PFI. The purposes of this paper are firstly to investigate the time series trend of the PPP projects in the wor ld, secondly to make international comparative study of the PPP-related institutions, and thirdly to propose the desirable improvements of the Japanese institution in many countries. The key issues of the proposal are the support systems for the risk management by the government which squares the rationale and transparence and the deregulation. Finally introduction of PFI scheme into the toll roads which managed by the public corporations of local governments are proposed as a first step in Japan.

Not So Titanic

NASA Image and Video Library

2015-07-13

Titan may be a "large" moon -- its name even implies it! -- but it is still dwarfed by its parent planet, Saturn. As it turns out, this is perfectly normal. Although Titan (3200 miles or 5150 kilometers across) is the second-largest moon in the solar system, Saturn is still much bigger, with a diameter almost 23 times larger than Titan's. This disparity between planet and moon is the norm in the solar system. Earth's diameter is "only" 3.7 times our moon's diameter, making our natural satellite something of an oddity. (Another exception to the rule: dwarf planet Pluto's diameter is just under two times that of its moon.) So the question isn't why is Titan so small (relatively speaking), but why is Earth's moon so big? This view looks toward the anti-Saturn hemisphere of Titan. North on Titan is up. The image was taken with the Cassini spacecraft wide-angle camera on April 18, 2015 using a near-infrared spectral filter with a passband centered at 752 nanometers. The view was acquired at a distance of approximately 930,000 miles (1.5 million kilometers) from Titan. Image scale is 56 miles (90 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18326

What Titan's phase curve can teach us about exoplanet atmospheres

NASA Astrophysics Data System (ADS)

García Muñoz, A.

2017-09-01

We report on the peculiar behavior of Titan's whole-disk brightness: its twilight is significantly brighter than its dayside. We propose that a similar behavior might also occur at exoplanets and that could be detectable in select cases. The detection of this optical phenomenon will provide valuable insight into the aerosol properties of the exoplanet atmosphere.

Titan's Radioactive Haze : Production and Fate of Radiocarbon On Titan

NASA Astrophysics Data System (ADS)

Lorenz, R. D.; Jull, A. J. T.; Swindle, T. D.; Lunine, J. I.

Just as cosmic rays interact with nitrogen atoms in the atmosphere of Earth to gener- ate radiocarbon (14C), the same process should occur in Titan`s nitrogen-rich atmo- sphere. Titan`s atmosphere is thick enough that cosmic ray flux, rather than nitrogen column depth, limits the production of 14 C. Absence of a strong magnetic field and the increased distance from the sun suggest production rates of 9 atom/cm2/s, approx- imately 4 times higher than Earth. On Earth the carbon is rapidly oxidised into CO2. The fate and detectability of 14C on Titan depends on the chemical species into which it is incorporated in Titan's reducing atmosphere : as methane it would be hopelessly diluted even in only the atmosphere (ignoring the other, much more massive carbon reservoirs likely to be present on Titan, like hydrocarbon lakes.) However, in the more likely case that the 14C attaches to the haze that rains out onto the surface (as tholin, HCN or acetylene and their polymers - a much smaller carbon reservoir) , haze in the atmosphere or recently deposited on the surface would therefore be quite intrinsically radioactive. Such activity may modify the haze electrical charging and hence its coag- ulation. Measurements with compact instrumentation on future in-situ missions could place useful constraints on the mass deposition rates of photochemical material on the surface and identify locations where surface deposits of such material are `freshest`.

Ground Based Monitoring of Cloud Activity on Titan

NASA Astrophysics Data System (ADS)

Corlies, Paul; Hayes, Alexander; Rojo, Patricio; Ádámkovics, Máté; Turtle, Elizabeth; Buratti, Bonnie

2014-11-01

We will report on the latest results of an on-going ground based monitoring campaign of Saturn’s moon Titan using the SINFONI (Spectrograph for INtegral Field Observations in the Near Infrared) instrument on the Very Large Telescope (VLT). Presently, much is still unknown about the complex and dynamic hydrologic system of Titan as observations have yet to be made through an entire Titan year (29.7 Earth years). Because of the limited ability to observe Titan with Cassini, a combined ground and spaced-based approach provides a steady cadence of observation throughout the duration of a Titan year. We will present the results of observations to date using the adaptive optics (AO) mode (weather dependent) of SINFONI. We have been regularly observing Titan since April 2014 for the purpose of monitoring and identifying clouds and have also been in collaboration with the Cassini team that has concurrent ISS observations and historical VIMS observations of clouds. Our discussion will focus on the various algorithms and approaches used for cloud identification and analysis. Currently, we are entering into a very interesting time for clouds and Titan hydrology as Saturn moves into north polar summer for the first time since Cassini entered the Saturnian system. The increased insolation that this will bring to the north, where the majority of the liquid methane lakes reside, will give us our first observations of the potentially complex interplay between surface liquid and atmospheric conditions. By carefully monitoring and characterizing clouds (size, optical depth, altitude, etc.) we will also be able to derive constraints that can help to guide and validate GCMs. Since the beginning of our observations, no clouds have been observed through ground based observations, while Cassini has only observed a single cloud event in the north polar region over Ligeia Mare. We will provide an update on the latest results of our cloud monitoring campaign and discuss how this

Intensive Titan exploration begins.

PubMed

Mahaffy, Paul R

2005-05-13

The Cassini Orbiter spacecraft first skimmed through the tenuous upper atmosphere of Titan on 26 October 2004. This moon of Saturn is unique in our solar system, with a dense nitrogen atmosphere that is cold enough in places to rain methane, the feedstock for the atmospheric chemistry that produces hydrocarbons, nitrile compounds, and Titan's orange haze. The data returned from this flyby supply new information on the magnetic field and plasma environment around Titan, expose new facets of the dynamics and chemistry of Titan's atmosphere, and provide the first glimpses of what appears to be a complex, fluid-processed, geologically young Titan surface.

A common agenda of global challenges. Japan and U.S. pool resources to tackle global issues including population and HIV / AIDS.

PubMed

1998-05-01

The Common Agenda for Cooperation in Global Perspective is a bilateral partnership established in 1993 between the US and Japan to address important global challenges of the 21st century such as global health and human development, including population and HIV/AIDS, global stability, protection of the global environment, and the advancement of science and technology. On the fifth anniversary of the agenda, representatives of the Japan and the US governments, international organizations, and private sectors discussed ways to further promote US-Japan cooperation under the agenda at a meeting held in Tokyo during March 12-13. Participants of the Common Agenda Open Forum also reviewed efforts made by Japan and the US under the agenda to address population and the environment. Forum participants focused upon developing new ideas for future cooperation between the governments, the private sector, and other nations, especially in the areas of health and the environment. The meeting was jointly organized by Japan's Ministry of Foreign Affairs and the US Department of State. Attention was also given during talks to diminishing international assistance budgets worldwide.

RESPONSE OF THE U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES IN PROTECTING CIVILIAN AMERICANS IN JAPAN DURING THE FUKUSHIMA NUCLEAR CRISIS.

PubMed

Simon, Steven L; Coleman, C Norman; Noska, Michael A; Bowman, Thomas

2012-05-01

Following the earthquake and tsunami in northern Japan on 11 March 2011, and the ensuing damage to the Fukushima Daiichi nuclear power plant complex, a request by the U.S. Ambassador to Japan to the U.S. Department of Health and Human Services (DHHS) Assistant Secretary for Preparedness and Response (ASPR) resulted in deployment of a five-person team of subject matter experts to the U.S. Embassy. The primary purpose of the deployment was to provide the U.S. Embassy in Tokyo with guidance on health and medical issues related to potential radiation exposure of U.S. citizens in Japan, including employees of the U.S. Department of State at consulates in Japan and American citizens living in or visiting Japan. At the request of the Government of Japan, the deployed health team also assisted Japanese experts in their public health response to the radiation incident. Over a three-week period in Japan and continuing for weeks after their return to the U.S., the team provided expertise in the areas of medical and radiation oncology, health physics, assessment of radiation dose and cancer risk, particularly to U.S. citizens living in Tokyo and the surrounding areas, food and water contamination and the acceptable limits, countermeasures to exposure such as potassium iodide (KI), the use of KI and an offered donation from the United States, evacuation and re-entry issues, and health/emergency-related communication strategies. This paper describes the various strategies used and observations made by the DHHS team during the first two months after the Fukushima crisis began.

RESPONSE OF THE U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES IN PROTECTING CIVILIAN AMERICANS IN JAPAN DURING THE FUKUSHIMA NUCLEAR CRISIS

PubMed Central

Simon, Steven L.; Coleman, C. Norman; Noska, Michael A.; Bowman, Thomas

2012-01-01

Following the earthquake and tsunami in northern Japan on 11 March 2011, and the ensuing damage to the Fukushima Daiichi nuclear power plant complex, a request by the U.S. Ambassador to Japan to the U.S. Department of Health and Human Services (DHHS) Assistant Secretary for Preparedness and Response (ASPR) resulted in deployment of a five-person team of subject matter experts to the U.S. Embassy. The primary purpose of the deployment was to provide the U.S. Embassy in Tokyo with guidance on health and medical issues related to potential radiation exposure of U.S. citizens in Japan, including employees of the U.S. Department of State at consulates in Japan and American citizens living in or visiting Japan. At the request of the Government of Japan, the deployed health team also assisted Japanese experts in their public health response to the radiation incident. Over a three-week period in Japan and continuing for weeks after their return to the U.S., the team provided expertise in the areas of medical and radiation oncology, health physics, assessment of radiation dose and cancer risk, particularly to U.S. citizens living in Tokyo and the surrounding areas, food and water contamination and the acceptable limits, countermeasures to exposure such as potassium iodide (KI), the use of KI and an offered donation from the United States, evacuation and re-entry issues, and health/emergency-related communication strategies. This paper describes the various strategies used and observations made by the DHHS team during the first two months after the Fukushima crisis began. PMID:24198437

Nationwide tsunami hazard assessment project in Japan

NASA Astrophysics Data System (ADS)

Hirata, K.; Fujiwara, H.; Nakamura, H.; Osada, M.; Ohsumi, T.; Morikawa, N.; Kawai, S.; Aoi, S.; Yamamoto, N.; Matsuyama, H.; Toyama, N.; Kito, T.; Murashima, Y.; Murata, Y.; Inoue, T.; Saito, R.; Akiyama, S.; Korenaga, M.; Abe, Y.; Hashimoto, N.

2014-12-01

In 2012, we began a project of nationwide Probabilistic Tsunami Hazard Assessment (PTHA) in Japan to support various measures (Fujiwara et al., 2013, JpGU; Hirata et al., 2014, AOGS). The most important strategy in the nationwide PTHA is predominance of aleatory uncertainty in the assessment but use of epistemic uncertainty is limited to the minimum, because the number of all possible combinations among epistemic uncertainties diverges quickly when the number of epistemic uncertainties in the assessment increases ; we consider only a type of earthquake occurrence probability distribution as epistemic uncertainty. We briefly show outlines of the nationwide PTHA as follows; (i) we consider all possible earthquakes in the future, including those that the Headquarters for Earthquake Research Promotion (HERP) of Japanese Government, already assessed. (ii) We construct a set of simplified earthquake fault models, called "Characterized Earthquake Fault Models (CEFMs)", for all of the earthquakes by following prescribed rules (Toyama et al., 2014, JpGU; Korenaga et al., 2014, JpGU). (iii) For all of initial water surface distributions caused by a number of the CEFMs, we calculate tsunamis by solving a nonlinear long wave equation, using FDM, including runup calculation, over a nesting grid system with a minimum grid size of 50 meters. (iv) Finally, we integrate information about the tsunamis calculated from the numerous CEFMs to get nationwide tsunami hazard assessments. One of the most popular representations of the integrated information is a tsunami hazard curve for coastal tsunami heights, incorporating uncertainties inherent in tsunami simulation and earthquake fault slip heterogeneity (Abe et al., 2014, JpGU). We will show a　PTHA along the eastern coast of Honshu, Japan, based on approximately 1,800 tsunami sources located within the subduction zone along the Japan Trench, as a prototype of the nationwide PTHA. This study is supported by part of the research

Titan Orbiter Aerorover Mission with Enceladus Science (TOAMES)

NASA Astrophysics Data System (ADS)

Sittler, E.; Cooper, J.; Mahaffy, P.; Fairbrother, D.; de Pater, I.; Schulze-Makuch, D.; Pitman, J.

2007-08-01

same time made us aware of how little we understand about these bodies. For example, the source, and/or recycling mechanism, of methane in Titan's atmosphere is still puzzling. Indeed, river beds (mostly dry) and lakes have been spotted, and occasional clouds have been seen, but the physics to explain the observations is still mostly lacking, since our "image" of Titan is still sketchy and quite incomplete. Enceladus, only 500 km in extent, is even more puzzling, with its fiery plumes of vapor, dust and ice emanating from its south polar region, "feeding" Saturn's E ring. Long term variability of magnetospheric plasma, neutral gas, E-ring ice grain density, radio emissions, and corotation of Saturn's planetary magnetic field in response to Enceladus plume activity are of great interest for Saturn system science. Both Titan and Enceladus are bodies of considerable astrobiological interest in view of high organic abundances at Titan and potential subsurface liquid water at Enceladus. We propose to develop a new mission to Titan and Enceladus, the Titan Orbiter Aerorover Mission with Enceladus Science (TOAMES), to address these questions using novel new technologies. TOAMES is a multi-faceted mission that starts with orbit insertion around Saturn using aerobraking with Titan's extended atmosphere. We then have an orbital tour around Saturn (for 1-2 years) and close encounters with Enceladus, before it goes into orbit around Titan (via aerocapture). During the early reconnaissance phase around Titan, perhaps 6 months long, the orbiter will use altimetry, radio science and remote sensing instruments to measure Titan's global topography, subsurface structure and atmospheric winds. This information will be used to determine where and when to release the Aerorover, so that it can navigate safely around Titan and identify prime sites for surface sampling and analysis. In situ instruments will sample the upper atmosphere which may provide the seed population for the complex

Culture and Healthy Eating: The Role of Independence and Interdependence in the U.S. and Japan

PubMed Central

Levine, Cynthia S.; Miyamoto, Yuri; Markus, Hazel Rose; Rigotti, Attilio; Boylan, Jennifer Morozink; Park, Jiyoung; Kitayama, Shinobu; Karasawa, Mayumi; Kawakami, Norito; Coe, Christopher L.; Love, Gayle D.; Ryff, Carol D.

2016-01-01

Healthy eating is important for physical health. Using large probability samples of middle-aged adults in the U.S. and Japan, we show that fitting with the culturally normative way of being predicts healthy eating. In the U.S, a culture that prioritizes and emphasizes independence, being independent predicts eating a healthy diet (an index of fish, protein, fruit, vegetables, reverse-coded sugared beverages, and reverse-coded high fat meat consumption; Study 1) and not using food as a way to cope with stress (Study 2a). In Japan, a culture that prioritizes and emphasizes interdependence, being interdependent predicts eating a healthy diet (Studies 1 and 2b). Further, reflecting the types of agency that are prevalent in each context, these relationships are mediated by autonomy in the U.S. and positive relations with others in Japan. These findings highlight the importance of understanding cultural differences in shaping healthy behavior and have implications for designing health-promoting interventions. PMID:27516421

Titan Saturn System Mission (TSSM) Enables Comparative Climatology with Earth

NASA Astrophysics Data System (ADS)

Reh, Kim; Lunine, J.; Coustenis, A.; Matson, D.; Beauchamp, P.; Erd, C.; Lebreton, J.

2009-09-01

Titan is a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on Earth. Its geology, from lakes and seas to broad river valleys and mountains, while carved in ice is, in its balance of processes, again most like Earth. Beneath this panoply of Earth-like processes an ice crust floats atop what appears to be a liquid water ocean. The Titan Saturn System Mission would seek to understand Titan as a system, in the same way that one would ask this question about Venus, Mars, and the Earth. How are distinctions between Titan and other worlds in the solar systems understandable in the context of the complex interplay of geology, hydrology, meteorology, and aeronomy? Is Titan an analogue for some aspect of Earth's history, past or future? Why is Titan endowed with an atmosphere when Ganymede is not? Titan is also rich in organic molecules_more so in its surface and atmosphere than anyplace in the solar system, including Earth (excluding our vast carbonate sediments). These molecules were formed in the atmosphere, deposited on the surface and, in coming into contact with liquid water may undergo an aqueous chemistry that could replicate aspects of life's origins. The second goal of the proposed TSSM mission is to understand the chemical cycles that generate and destroy organics and assess the likelihood that they can tell us something of life's origins. This work was performed at the Jet Propulsion Laboratory-California Institute of Technology, under contract to NASA.

Titan's Variable Plasma Interaction

NASA Astrophysics Data System (ADS)

Ledvina, S. A.; Brecht, S. H.

2015-12-01

Cassini observations have found that the plasma and magnetic field conditions upstream of Titan are far more complex than they were thought to be after the Voyager encounter. Rymer et al., (2009) used the Cassini Plasma Spectrometer (CAPS) electron observations to classify the plasma conditions along Titan's orbit into 5 types (Plasma Sheet, Lobe, Mixed, Magnetosheath and Misc.). Nemeth et al., (2011) found that the CAPS ion observations could also be separated into the same plasma regions as defined by Rymer et al. Additionally the T-96 encounter found Titan in the solar wind adding a sixth classification. Understanding the effects of the variable upstream plasma conditions on Titan's plasma interaction and the evolution of Titan's ionosphere/atmosphere is one of the main objectives of the Cassini mission. To compliment the mission we perform hybrid simulations of Titan's plasma interaction to examine the effects of the incident plasma distribution function and the flow velocity. We closely examine the results on Titan's induced magnetosphere and the resulting pickup ion properties.

Democratic Reforms and Women's Higher Education during the U.S. Occupation of Japan, 1945-1952.

ERIC Educational Resources Information Center

Moroishi, Yasumi; Martin, Don T.

This paper aims to show the significance of the educational reforms of women's higher education during the U.S. occupation of post-World War II Japan. To help fill the gap of research on women's higher education in Japan, focus is on an historical analysis of women's higher education reform policies. Since educational reforms are not…

VIMS spectral mapping observations of Titan during the Cassini prime mission

USGS Publications Warehouse

Barnes, J.W.; Soderblom, J.M.; Brown, R.H.; Buratti, B.J.; Sotin, Christophe; Baines, K.H.; Clark, R.N.; Jaumann, R.; McCord, T.B.; Nelson, R.; Le, Mouelic S.; Rodriguez, S.; Griffith, C.; Penteado, P.; Tosi, F.; Pitman, K.M.; Soderblom, L.; Stephan, K.; Hayne, P.; Vixie, G.; Bibring, J.-P.; Bellucci, G.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Langevin, Y.; Matson, D.L.; Nicholson, P.D.; Sicardy, B.

2009-01-01

This is a data paper designed to facilitate the use of and comparisons to Cassini/visual and infrared mapping spectrometer (VIMS) spectral mapping data of Saturn's moon Titan. We present thumbnail orthographic projections of flyby mosaics from each Titan encounter during the Cassini prime mission, 2004 July 1 through 2008 June 30. For each flyby we also describe the encounter geometry, and we discuss the studies that have previously been published using the VIMS dataset. The resulting compliation of metadata provides a complementary big-picture overview of the VIMS data in the public archive, and should be a useful reference for future Titan studies. ?? 2009 Elsevier Ltd.

CASSINI. Report on the Phase A study: Saturn Orbiter and Titan probe

NASA Technical Reports Server (NTRS)

1988-01-01

An in-depth, second phase exploration of Saturn is proposed. The scientific objectives involving Titan, Saturn's rings, icy satellites, magnetosphere, Jupiter, asteroids, and cruise science are covered. Other topics presented include: (1) the model payloads; (2) project requirements; (3) mission; (4) launch vehicle; (5) the orbiter system; (6) the Titan probe system; (7) mission operations; (8) management; and (9) development plan.

The astrobiology of Titan

NASA Astrophysics Data System (ADS)

Raulin, F.; Coll, P.; Cabane, M.; Hebrard, E.; Israel, G.; Nguyen, M.-J.; Szopa, C.; Gpcos Team

Largest satellite of Saturn and the only satellite in the solar system having a dense atmosphere, Titan is one of the key planetary bodies for astrobiological studies, due to several aspects: Its analogies with planet Earth, in spite of much lower temperatures, The Cassini-Huygens data have largely confirmed the many analogies between Titan and our own planet. Both have similar vertical temperature profiles, (although much colder, of course, on Titan). Both have condensable and non condensable greenhouse gases in their atmosphere. Both are geologically very active. Furthermore, the data also suggest strongly the presence of a methane cycle on Titan analogous to the water cycle on Earth. The presence of an active organic chemistry, involving several of the key compounds of prebiotic chemistry. The recent data obtained from the Huygens instruments show that the organic matter in Titan low atmosphere (stratosphere and troposphere) is mainly concentrated in the aerosol particles. Because of the vertical temperature profile in this part of the atmosphere, most of the volatile organics are probably mainly condensed on the aerosol particles. The nucleus of these particles seems to be made of complex macromolecular organic matter, well mimicked in the laboratory by the "Titan's tholins". Now, laboratory tholins are known to release many organic compounds of biological interest, such as amino acids and purine and pyrimidine bases, when they are in contact with liquid water. Such hydrolysis may have occurred on the surface of Titan, in the bodies of liquid water which episodically may form on Titan's surface from meteoritic and cometary impacts. The formation of biologically interesting compounds may also occur in the deep water ocean, from the hydrolysis of complex organic material included in the chrondritic matter accreted during the formation of Titan. The possible emergence and persistence of Life on Titan 1 All ingredients which seems necessary for Life are present on

Titan: Kraken and Ligeia In Sharper Focus

NASA Image and Video Library

2017-03-15

As it sped away from a relatively distant encounter with Titan on Feb. 17, 2017, NASA's Cassini spacecraft captured this mosaic view of the moon's northern lakes and seas. Cassini's viewing angle over Kraken Mare and Ligeia Mare was better during this flyby than previous encounters, providing increased contrast for viewing these seas. Because the spacecraft is peering through less of Titan's haze toward Kraken and Ligeia, more details on their shorelines are visible, compared to earlier maps. This was one of several "non-targeted" Cassini Titan flybys in 2017 that allow the mission to image the moon's north polar region and track clouds there. ("Non-targeted" means Cassini did not have to use any rocket-thruster firings to steer itself toward the flyby.) Several prominent cloud streaks are visible at mid-latitudes between 45 and 55 degrees north latitude, on the right side of the image. Smaller bright clouds are seen just above the sea called Punga Mare (roughly at center). Scientists are seeing increasing cloud activity in Titan's north polar region as the seasons continue to change from spring to summer there, though not as much as predicted by models of Titan's atmosphere. The images in this mosaic were taken with the Cassini spacecraft narrow-angle camera using a spectral filter sensitive to wavelengths of near-infrared light centered at 938 nanometers. The view was obtained at a distance of approximately 150,700 miles (242,500 kilometers) from Titan. Image scale is about 1.6 miles (2.6 kilometers) per pixel. The view is an orthographic projection centered on 68 degrees north latitude, 225 degrees west longitude. An orthographic view is most like the view seen by a distant observer looking through a telescope. http://photojournal.jpl.nasa.gov/catalog/PIA21434

Titan Orbiter Aerorover Mission with Enceladus Science (TOAMES)

NASA Technical Reports Server (NTRS)

Sittler, Edward C.; Cooper, J.; Mahaffy, P.; Fairbrother D.; dePater, I.; Schultze-Makuch, D.; Pitman, J.

2007-01-01

Cassini and Huygens have made exciting discoveries at Titan and Enceladus, and at the same time made us aware of how little we understand about these bodies. For example, the source, and/or recycling mechanism, of methane in Titan's atmosphere is still puzzling. Indeed, river beds (mostly dry) and lakes have been spotted, and occasional clouds have been seen, but the physics to explain the observations is still mostly lacking, since our "image" of Titan is still sketchy and quite incomplete. Enceladus, only -500 km in extent, is even more puzzling, with its fiery plumes of vapor, dust and ice emanating from its south polar region, "feeding" Saturn's E ring. Long term variability of magnetospheric plasma, neutral gas, E-ring ice grain density, radio emissions, and corotation of Saturn's planetary magnetic field in response to Enceladus plume activity are of great interest for Saturn system science. Both Titan and Enceladus are bodies of considerable astrobiological interest in view of high organic abundances at Titan and potential subsurface liquid water at Enceladus. We propose to develop a new mission to Titan and Enceladus, the Titan Orbiter Aerorover Mission with Enceladus Science (TOAMES), to address these questions using novel new technologies. TOAMES is a multi-faceted mission that starts with orbit insertion around Saturn using aerobraking with Titan's extended atmosphere. We then have an orbital tour around Saturn (for 1-2 years) and close encounters with Enceladus, before it goes into orbit around Titan (via aerocapture). During the early reconnaissance phase around Titan, perhaps 6 months long, the orbiter will use altimetry, radio science and remote sensing instruments to measure Titan's global topography, subsurface structure and atmospheric winds. This information will be used to determine where and when to release the Aerorover, so that it can navigate safely around Titan and identify prime sites for surface sampling and analysis. In situ instruments

Connecting Indigenous Ainu, University and Local Industry in Japan: The Urespa Project

ERIC Educational Resources Information Center

Maeda, Koji; Okano, Kaori H.

2013-01-01

This paper examines how collaboration amongst university, indigenous community and private sector companies can promote Ainu participation in higher education, drawing on a case study of the Urespa Project in Sapporo University, Japan. In this project, the university offers scholarships to Ainu students, requiring them to take a special course in…

Mapping of Titan: Results from the first Titan radar passes

USGS Publications Warehouse

Stofan, E.R.; Lunine, J.I.; Lopes, R.; Paganelli, F.; Lorenz, R.D.; Wood, C.A.; Kirk, R.; Wall, S.; Elachi, C.; Soderblom, L.A.; Ostro, S.; Janssen, M.; Radebaugh, J.; Wye, L.; Zebker, H.; Anderson, Y.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Stiles, B.; Vetrella, S.; West, R.

2006-01-01

The first two swaths collected by Cassini's Titan Radar Mapper were obtained in October of 2004 (Ta) and February of 2005 (T3). The Ta swath provides evidence for cryovolcanic processes, the possible occurrence of fluvial channels and lakes, and some tectonic activity. The T3 swath has extensive areas of dunes and two large impact craters. We interpret the brightness variations in much of the swaths to result from roughness variations caused by fracturing and erosion of Titan's icy surface, with additional contributions from a combination of volume scattering and compositional variations. Despite the small amount of Titan mapped to date, the significant differences between the terrains of the two swaths suggest that Titan is geologically complex. The overall scarcity of impact craters provides evidence that the surface imaged to date is relatively young, with resurfacing by cryovolcanism, fluvial erosion, aeolian erosion, and likely atmospheric deposition of materials. Future radar swaths will help to further define the nature of and extent to which internal and external processes have shaped Titan's surface. ?? 2006 Elsevier Inc. All rights reserved.

The Greenhouse and Anti-Greenhouse Effects on Titan

NASA Technical Reports Server (NTRS)

McKay, C. P.; Cuzzi, Jeffrey N. (Technical Monitor)

1994-01-01

Titan is the largest moon of Saturn and is the only moon in the solar system with a substantial atmosphere. Its atmosphere is mostly made of nitrogen, with a few percent CH4, 0.1% H2 and an uncertain level of Ar (less than 10%). The surface pressure is 1.5 atms and the surface temperature is 95 K, decreasing to 71 at the tropopause before rising to stratospheric temperatures of 180 K. In pressure and composition Titan's atmosphere is the closest twin to Earth's. The surface of Titan remains unknown, hidden by the thick smog layer, but it may be an ocean of liquid methane and ethane. Titan's atmosphere has a greenhouse effect which is much stronger than the Earth's - 92% of the surface warming is due to greenhouse radiation. However an organic smog layer in the upper atmosphere produces an anti-greenhouse effect that cuts the greenhouse warming in half - removing 35% of the incoming solar radiation. Models suggest that during its formation Titan's atmosphere was heated to high temperatures due to accretional energy. This was followed by a cold Triton-like period which gradually warmed to the present conditions. The coupled greenhouse and haze anti-greenhouse may be relevant to recent suggestions for haze shielding of a CH4 - NH3 early atmosphere on Earth or Mars. When the NASA/ESA mission to the Saturn System, Cassini, launches in a few years it will carry a probe that will be sent to the surface of Titan and show us this world that is strange and yet in many ways similar to our own.

Photochemical aerosol formation in planetary atmospheres: A comparison between Pluto and Titan

NASA Astrophysics Data System (ADS)

Lavvas, Panayotis; Strobel, Darrell F.; Lellouch, Emmanuel; Gurwell, Mark A.; Cheng, Andrew F.; Summers, Michael; Gladstone, Randy

2016-10-01

The New Horizons mission observations have revealed us that Pluto's atmosphere is rich in photochemical hazes that extend to high altitudes above its surface [1], apparently similar to those observed in Titan's atmosphere [2].We use detailed models combining photochemistry and microphysics in order to simulate the aerosol formation and growth in Pluto's atmosphere, as performed for Titan's atmosphere [3]. Here we discuss the possible mechanisms leading to the formation of haze particles in Pluto's atmosphere, and we evaluate the contribution of different growth processes (e.g. coagulation vs. condensation) to the resulting particle properties.Moreover we investigate the role of these particles in the radiative balance of Pluto's atmosphere and we compare the resulting particle properties, with those retrieved for Titan's upper atmosphere based on Cassini observations [4]. We discuss the similarities and difference between Pluto's and Titan's aerosols.[1] Gladstone et al., 2016, Science, 351, 6271[2] West et al., 2015, Titan's Haze, in Titan, Interior, Surface, Atmosphere and Space environment, Cambridge University Press[3] Lavvas et al., 2013, PNAS, pnas.1217059110[4] Lavvas et al., 2015, DPS47, id.205.08

Hydrothermal synthesis of barium strontium titanate and bismuth titanate materials

NASA Astrophysics Data System (ADS)

Xu, Huiwen

Hydrothermal processing facilitates the synthesis of crystalline ceramic materials of varying composition or complex crystal structure. The present work can be divided into two parts. First is to study the low temperature hydrothermal synthesis of bismuth titanate. Second is to study both thermodynamic and kinetic aspects of the hydrothermally synthesized barium strontium titanate. A chelating agent was used to form a Bi-Ti gel precursor. By hydrothermally treating the Bi-Ti gel, crystalline bismuth titanate has been synthesized at 160°C for the first time. Microstructural evolution during the low temperature synthesis of bismuth titanate can be divided into two stages, including condensation of Bi-Ti gel particles and crystallization of bismuth titanate. Crystallization of bismuth titanate occurred by an in situ transformation mechanism at an early stage followed by a dissolution-reprecipitation mechanism. Phase separation was observed in hydrothermally synthesized barium strontium titanate (BST). By hydrothermally treating BST powders between 250°C--300°C, an asymmetrical miscibility gap was found in the BaTiO3-SrTiO 3 system at low temperatures (T ≤ 320°C). A subregular solid solution model was applied to calculate the equilibrium compositions and the Gibbs free energy of formation of BST solid solution at low temperatures (T ≤ 320°C). The Gibbs free energy of formation of Sr-rich BST phase is larger than that of Ba-rich BST phase. Kinetic studies of single phase BST solid solution at 80°C show that, compared to the BaTiO3 or Ba-rich BST, SrTiO3 and Sr-rich BST powders form at lower reaction rates.

Constructing failure in big biology: The socio-technical anatomy of Japan's Protein 3000 Project.

PubMed

Fukushima, Masato

2016-02-01

This study focuses on the 5-year Protein 3000 Project launched in 2002, the largest biological project in Japan. The project aimed to overcome Japan's alleged failure to contribute fully to the Human Genome Project, by determining 3000 protein structures, 30 percent of the global target. Despite its achievement of this goal, the project was fiercely criticized in various sectors of society and was often branded an awkward failure. This article tries to solve the mystery of why such failure discourse was prevalent. Three explanatory factors are offered: first, because some goals were excluded during project development, there was a dynamic of failed expectations; second, structural genomics, while promoting collaboration with the international community, became an 'anti-boundary object', only the absence of which bound heterogeneous domestic actors; third, there developed an urgent sense of international competition in order to obtain patents on such structural information.

Dunelands of Titan

NASA Image and Video Library

2015-11-02

Saturn's frigid moon Titan has some characteristics that are oddly similar to Earth, but still slightly alien. It has clouds, rain and lakes (made of methane and ethane), a solid surface (made of water ice), and vast dune fields (filled with hydrocarbon sands). The dark, H-shaped area seen here contains two of the dune-filled regions, Fensal (in the north) and Aztlan (to the south). Cassini's cameras have frequently monitored the surface of Titan (3200 miles or 5150 kilometers across) to look for changes in its features over the course of the mission. Any changes would help scientists better understand different phenomena like winds and dune formation on this strangely earth-like moon. For a closer view of Fensal-Aztlan, see PIA07732 . This view looks toward the leading side of Titan. North on Titan is up. The image was taken with the Cassini spacecraft narrow-angle camera on July 25, 2015 using a spectral filter sensitive to wavelengths of near-infrared light centered at 938 nanometers. The view was obtained at a distance of approximately 450,000 miles (730,000 kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 32 degrees. Image scale is 3 miles (4 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18341

Fragile Relationships: Japan, High Technology, and U.S. Vital Interests

DTIC Science & Technology

1990-04-04

costs ; better manufacturing techniques; higher quality products; excellent marketing plans; and, direct and indirect government support. 5 Akio...short-term and have not looked to the future, as have the Japanese. The stockholders’ demand for large, quick profits often cost market shares and...grip the country as we use increasing amounts of our wealth to service the national debt. Japan will be our creditor. U.S. market shares, both

Spatial Variations of Chemical Abundances in Titan's Atmosphere as Revealed by ALMA

NASA Astrophysics Data System (ADS)

Thelen, Alexander E.; Nixon, Conor; Chanover, Nancy J.; Molter, Edward; Serigano, Joseph; Cordiner, Martin; Charnley, Steven B.; Teanby, Nicholas A.; Irwin, Patrick

2016-10-01

Complex organic molecules in Titan's atmosphere - formed through the dissociation of N2 and CH4 - exhibit latitudinal variations in abundance as observed by Cassini. Chemical species including hydrocarbons - such as CH3CCH - and nitriles - HCN, HC3N, CH3CN, and C2H5CN - may show spatial abundance variations as a result of atmospheric circulation, photochemical production and subsequent destruction throughout Titan's seasonal cycle. Recent calibration images of Titan taken by the Atacama Large Millimeter/Submillimeter Array (ALMA) with beam sizes of ~0.3'' allow for measurements of rotational transition lines of these species in spatially resolved regions of Titan's disk. We present abundance profiles obtained from public ALMA data taken in 2014, as Titan transitioned into northern summer. Abundance profiles in Titan's lower/middle atmosphere were retrieved by modeling high resolution ALMA spectra using the Non-linear Optimal Estimator for MultivariatE Spectral analySIS (NEMESIS) radiative transfer code. These retrievals were performed using spatial temperature profiles obtained by modeling strong CO lines from datasets taken in similar times with comparable resolution. We compare the abundance variations of chemical species to measurements made using Cassini data. Comparisons of chemical species with strong abundance enhancements over the poles will inform our knowledge of chemical lifetimes in Titan's atmosphere, and allow us to observe the important changes in production and circulation of numerous organic molecules which are attributed to Titan's seasons.

Cassini / Huygens at Saturn and Titan

NASA Technical Reports Server (NTRS)

Mitchell, Robert T.

2005-01-01

The Cassin/Huygens Project is a joint undertaking between NASA, the European Space Agency, and the Italian Space Agency to conduct an in-depth exploration of the Saturnian system. The spacecraft consists of an orbiter vehicle and an atmospheric probe which has completed its mission in the atmosphere and on the surface of Titan, the largest moon of Saturn. The spacecraft was launched on October 15, 1997, has completed its nearly seven years of interplanetary flight, and by the time of the 56th IAC, it will have completed 17 of its planned 75 orbits during its four-year prime orbital mission. This paper gives an overview of the mission, and describes in detail the accomplishments and events over the past year, including the spectacularly successful descent of the .European Space Agency's Huygens probe to the surface of Titan. Initial scientific results from both the Huygens mission as well as from the first one-and-a-quarter years of orbiting Saturn are summarized. The plans for the remainder of the orbiter's tour of the Saturn system and the many flybys of Titan and the smaller icy satellites are described.

Cancer incidence and incidence rates in Japan in 2008: a study of 25 population-based cancer registries for the Monitoring of Cancer Incidence in Japan (MCIJ) project.

PubMed

Matsuda, Ayako; Matsuda, Tomohiro; Shibata, Akiko; Katanoda, Kota; Sobue, Tomotaka; Nishimoto, Hiroshi

2014-04-01

The Japan Cancer Surveillance Research Group aimed to estimate the cancer incidence in Japan in 2008 based on data collected from 25 of 34 population-based cancer registries, as part of the Monitoring of Cancer Incidence in Japan project. The incidence in Japan for 2008 was estimated to be 749 767 (C00-C96). Stomach cancer and breast cancer were the leading types of cancer in males and females, respectively.

Two Titans

NASA Image and Video Library

2017-08-11

These two views of Saturn's moon Titan exemplify how NASA's Cassini spacecraft has revealed the surface of this fascinating world. Cassini carried several instruments to pierce the veil of hydrocarbon haze that enshrouds Titan. The mission's imaging cameras also have several spectral filters sensitive to specific wavelengths of infrared light that are able to make it through the haze to the surface and back into space. These "spectral windows" have enable the imaging cameras to map nearly the entire surface of Titan. In addition to Titan's surface, images from both the imaging cameras and VIMS have provided windows into the moon's ever-changing atmosphere, chronicling the appearance and movement of hazes and clouds over the years. A large, bright and feathery band of summer clouds can be seen arcing across high northern latitudes in the view at right. These views were obtained with the Cassini spacecraft narrow-angle camera on March 21, 2017. Images taken using red, green and blue spectral filters were combined to create the natural-color view at left. The false-color view at right was made by substituting an infrared image (centered at 938 nanometers) for the red color channel. The views were acquired at a distance of approximately 613,000 miles (986,000 kilometers) from Titan. Image scale is about 4 miles (6 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21624

COSPAR Workshop on Planetary Protection for Titan and Ganymede

NASA Astrophysics Data System (ADS)

Rummel, J. D.; Raulin, F.; Ehrenfreund, P.

2010-06-01

During the deliberations of the COSPAR Workshop on Planetary Protection for Outer Planet Satellites and Small Solar System Bodies (Rummel et al., 2009), held in Vienna in April 2009, a number of bodies in the outer Solar System were identified as being potentially in the "II+" category consistent with the COSPAR categorization scheme, referring to a body that is of interest to chemical evolution and the origin of life, but whose potential to support living organisms is undecided, including at least Titan, Ganymede, Triton, and the Pluto-Charon system (see Appendix C). Of these objects, Titan is the highest priority target for a near-term robotic flagship mission and Ganymede is also the subject of flagship mission interest. To address the concerns that were raised in Vienna about the categorization of Titan and Ganymede (as "II+") required another dedicated workshop to concentrate on those two bodies, a meeting was planned and held jointly by NASA, ESA, and COSPAR during the winter of 2009- 2010. This workshop included additional experts on Titan and Ganymede who were not able to participate in the Vienna meeting, and allowed the attendees to inspect detailed information about the most recent Cassini-Huygens results as well as the most current interpretation of the data available for both Titan and Ganymede. The goal of this workshop was to resolve the mission category for Titan and Ganymede and to develop a consensus on the II versus II+ dichotomy, taking into account both the conservative nature of planetary protection policy and the physical constraints on the Titan system and on Ganymede - the two largest moons in our solar system. This report summarizes the findings and recommendations from the workshop. The document will be distributed to the COSPAR Planetary Protection panel for consideration prior to the next General Assembly meeting in Bremen (Germany) during July 2010. Results from the Titan/Ganymede study will also be coordinated in a larger evaluation

Hypsometry of Titan

NASA Astrophysics Data System (ADS)

Lorenz, Ralph D.; Turtle, Elizabeth P.; Stiles, Bryan; Le Gall, Alice; Hayes, Alexander; Aharonson, Oded; Wood, Charles A.; Stofan, Ellen; Kirk, Randy

2011-01-01

Cassini RADAR topography data are used to evaluate Titan's hypsometric profile, and to make comparisons with other planetary bodies. Titan's hypsogram is unimodal and strikingly narrow compared with the terrestrial planets. To investigate topographic extremes, a novel variant on the classic hypsogram is introduced, with a logarithmic abscissa to highlight mountainous terrain. In such a plot, the top of the terrestrial hypsogram is quite distinct from those of Mars and Venus due to the 'glacial buzz-saw' that clips terrestrial topography above the snowline. In contrast to the positive skew seen in other hypsograms, with a long tail of positive relief due to mountains, there is an indication (weak, given the limited data for Titan so far) that the Titan hypsogram appears slightly negatively skewed, suggesting a significant population of unfilled depressions. Limited data permit only a simplistic comparison of Titan topography with other icy satellites but we find that the standard deviation of terrain height (albeit at different scales) is similar to those of Ganymede and Europa.

Integration of Titan supercomputer at OLCF with ATLAS Production System

NASA Astrophysics Data System (ADS)

Barreiro Megino, F.; De, K.; Jha, S.; Klimentov, A.; Maeno, T.; Nilsson, P.; Oleynik, D.; Padolski, S.; Panitkin, S.; Wells, J.; Wenaus, T.; ATLAS Collaboration

2017-10-01

The PanDA (Production and Distributed Analysis) workload management system was developed to meet the scale and complexity of distributed computing for the ATLAS experiment. PanDA managed resources are distributed worldwide, on hundreds of computing sites, with thousands of physicists accessing hundreds of Petabytes of data and the rate of data processing already exceeds Exabyte per year. While PanDA currently uses more than 200,000 cores at well over 100 Grid sites, future LHC data taking runs will require more resources than Grid computing can possibly provide. Additional computing and storage resources are required. Therefore ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. In this paper we will describe a project aimed at integration of ATLAS Production System with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). Current approach utilizes modified PanDA Pilot framework for job submission to Titan’s batch queues and local data management, with lightweight MPI wrappers to run single node workloads in parallel on Titan’s multi-core worker nodes. It provides for running of standard ATLAS production jobs on unused resources (backfill) on Titan. The system already allowed ATLAS to collect on Titan millions of core-hours per month, execute hundreds of thousands jobs, while simultaneously improving Titans utilization efficiency. We will discuss the details of the implementation, current experience with running the system, as well as future plans aimed at improvements in scalability and efficiency. Notice: This manuscript has been authored, by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to

Encouragement from Jupiter for Europe's Titan Probe

NASA Astrophysics Data System (ADS)

1996-04-01

Huygens will transmit scientific information for 150 minutes, from the outer reaches of Titan's cold atmosphere and all the way down to its enigmatic surface. For comparison, the Jupiter Probe radioed scientific data for 58 minutes as it descended about 200 kilometres into the outer part of the atmosphere of the giant planet. The parachutes controlling various stages of Huygens' descent will rely upon a system for deployment designed and developed in Europe that is nevertheless similar to that used by the Jupiter Probe. The elaborate sequence of operations in Huygens worked perfectly during a dramatic drop test from a stratospheric balloon over Sweden in May 1995, which approximated as closely as possible to events on Titan. The performance of the American Probe at Jupiter renews the European engineers' confidence in their own descent control system, and also in the lithium sulphur-dioxide batteries which were chosen to power both Probes. "The systems work after long storage in space," comments Hamid Hassan, ESA's Project Manager for Huygens. "Huygens will spend seven years travelling to Saturn's vicinity aboard the Cassini Orbiter. The Jupiter Probe was a passenger in Galileo for six years before its release, so there is no reason to doubt that Huygens will work just as well." Huygens will enter the outer atmosphere of Titan at 20,000 kilometres per hour. A heat shield 2.7 metres in diameter will withstand the friction and slow the Probe to a speed at which parachutes can be deployed. The size of the parachute for the main phase of the descent is chosen to allow Huygens to reach the surface in about 2 hours. The batteries powering Huygens will last for about 21/2 hours. Prepared for surprises A different perspective on the Jupiter Probe comes from Jean-Pierre Lebreton, ESA's Project Scientist for Huygens. The results contradicted many preconceptions of the Galileo scientists, particularly about the abundance of water and the structure of cloud layers. Arguments

The United States and Japan pursue a common agenda.

PubMed

Westley, S B

1996-10-01

In July 1993, the US and Japan formed the "Common Agenda for Cooperation in Global Perspective," an economic alliance to promote health and human development, respond to challenges to global stability, protect the global environment, advance science and technology, and foster exchanges for mutual understanding. A Global Issues Initiative (GII) has been created within this framework to support family planning, HIV and sexually transmitted disease prevention and control efforts, maternal and child health, primary health care, and women's empowerment. Participation in the GII has led Japan to more than double the technical assistance it provides and to broaden its geographic focus from Asia to the entire developing world. The US continues to fund population and health programs in more than 50 countries. The Common Agenda grew out of a US-Japan development assistance policy consultation dialogue known as the "Honolulu process," which sought ways to promote mutual understanding among US and Japanese development assistance personnel (through international internships) and nongovernmental organizations and to identify specific areas for joint or parallel development projects. Cooperative activities are underway in the Philippines, Indonesia, Bangladesh, India, Ghana, Peru, Guatemala, Mexico, and Jamaica. Joint project evaluations have also taken place in Zambia and Ghana. The Common Agenda's Children's Health Initiative has supported such initiatives as achieving child immunization in the Newly Independent States and joint efforts to eradicate polio and micronutrient disorders. The Women in Development initiative enhances girls' education and assists women engaged in small-scale enterprises. After initial difficulties in agreeing on joint strategies, the Common Agenda has been an "overwhelmingly positive" experience with the potential to meet critical challenges, because Japan and the US account for 40% of all development assistance worldwide.

Cultural Perspectives on Aging and Well-Being: A Comparison of Japan and the U.S.

PubMed Central

Karasawa, Mayumi; Curhan, Katherine B.; Markus, Hazel Rose; Kitayama, Shinobu S.; Love, Gayle Dienberg; Radler, Barry T.; Ryff, Carol D.

2011-01-01

This study investigated age differences in multiple aspects of psychological well-being among midlife and older adults in Japan (N = 482) and the U.S. (N = 3,032) to test the hypothesis that older Japanese adults would rate aspects of their well-being (personal growth, purpose in life, positive relations with others) more highly that older U.S. adults. Partial support was found: older adults in Japan showed higher scores on personal growth compared to midlife adults, whereas the opposite age pattern was found in the U.S. However, purpose in life showed lower scores for older adults in both cultural contexts. Interpersonal well-being, as hypothesized, was rated significantly higher, relative to the overall well-being, among Japanese compared to U.S. respondents, but only among younger adults. Women in both cultures showed higher interpersonal well-being, but also greater negative affect compared with men. Suggestions for future inquiries to advance understanding of aging and well-being in distinct cultural contexts are detailed. PMID:21922800

Project oriented klystron developments in Japan, China and India

NASA Astrophysics Data System (ADS)

Fukuda, Shigeki

2017-12-01

Modern accelerators are based on the rf technology and the klystron is the one of key components. Some special accelerator projects require their specified klystrons i.e., project-oriented klystrons. In this paper, project-oriented klystron developments for a decade in Japan are described. Related projects are ILC, cERL and SKEKB. Usually klystron is very expensive but has a finite life and needs to procure again. Trial to introduce the compatible tubes and have a competitive tender to reduce the cost is described. At the same time, since an efficiency improvement is one of the recent trend, such an attempt is also presented. International klystron collaboration among the Asian countries has been performed for a long time. In this paper, collaboration with China and India is introduced. Since topics are covered mainly author's experience, related counties described are limited.

Private Sector Initiative Between the U.S. and Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1998-09-30

OAK-A258 Private Sector Initiative Between the U.S. and Japan. This report for calendar years 1993 through September 1998 describes efforts performed under the Private Sector Initiatives contract. The report also describes those efforts that have continued with private funding after being initiated under this contract. The development of a pyrochemical process, called TRUMP-S, for partitioning actinides from PUREX waste, is described in this report. This effort is funded by the Central Research Institute of Electric Power Industry (CRIEPI), KHI, the United States Department of Energy, and Boeing.

Lakes on Titan

NASA Image and Video Library

2006-07-24

The Cassini spacecraft, using its radar system, has discovered very strong evidence for hydrocarbon lakes on Titan. Dark patches, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan north pole

Cryovolcanic features on Titan's surface as revealed by the Cassini Titan Radar Mapper

USGS Publications Warehouse

Lopes, R.M.C.; Mitchell, K.L.; Stofan, E.R.; Lunine, J.I.; Lorenz, R.; Paganelli, F.; Kirk, R.L.; Wood, C.A.; Wall, S.D.; Robshaw, L.E.; Fortes, A.D.; Neish, Catherine D.; Radebaugh, J.; Reffet, E.; Ostro, S.J.; Elachi, C.; Allison, M.D.; Anderson, Y.; Boehmer, R.; Boubin, G.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Janssen, M.A.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.O.; Ori, G.; Orosei, R.; Picardi, G.; Posa, F.; Roth, L.E.; Seu, R.; Shaffer, S.; Soderblom, L.A.; Stiles, B.; Vetrella, S.; West, R.D.; Wye, L.; Zebker, H.A.

2007-01-01

The Cassini Titan Radar Mapper obtained Synthetic Aperture Radar images of Titan's surface during four fly-bys during the mission's first year. These images show that Titan's surface is very complex geologically, showing evidence of major planetary geologic processes, including cryovolcanism. This paper discusses the variety of cryovolcanic features identified from SAR images, their possible origin, and their geologic context. The features which we identify as cryovolcanic in origin include a large (180 km diameter) volcanic construct (dome or shield), several extensive flows, and three calderas which appear to be the source of flows. The composition of the cryomagma on Titan is still unknown, but constraints on rheological properties can be estimated using flow thickness. Rheological properties of one flow were estimated and appear inconsistent with ammonia-water slurries, and possibly more consistent with ammonia-water-methanol slurries. The extent of cryovolcanism on Titan is still not known, as only a small fraction of the surface has been imaged at sufficient resolution. Energetic considerations suggest that cryovolcanism may have been a dominant process in the resurfacing of Titan. ?? 2006 Elsevier Inc.

Titan's Interior Chemical Composition: A Thermochemical Assessment*

NASA Astrophysics Data System (ADS)

Howard, Michael; Zaug, J. M.; Khare, B. N.; McKay, C. P.

2007-10-01

We study the interior composition of Titan using thermal chemical equilibrium calculations that are valid to high pressures and temperatures. The equations of state are based on exponential-6 fluid theory and have been validated against experimental data up to a few Mbars in pressure and approximately 20000K in temperature. In addition to CHNO molecules, we account for multi-phases of carbon, water and a variety of metals such as Al and Fe, and their oxides. With these fluid equations of state, chemical equilibrium is calculated for a set of product species. As the temperature and pressure evolves for increasing depth in the interior, the chemical equilibrium shifts. We assume that Titan is initially composed of comet material, which we assume to be solar, except for hydrogen, which we take to be depleted by a factor 1/690. We find that a significant amount of nitrogen is in the form of n2, rather than nh3. Moreover, above 12 kbars, as is the interior pressure of Titan, a significant amount of the carbon is in the form of graphite, rather than co2 and ch4. We discuss the implications of these results for understanding the atmospheric and surface composition of Titan. • This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Titan's impact history

NASA Astrophysics Data System (ADS)

Zahnle, Kevin

2010-04-01

Impacts play a major role in the growth and evolution of planets, satellites, and other nameless things. Titan is no exception. This talk will address a subset of the following topics: (i) The modern impact rate is constrained by the population of Centaurs and the impact rate at Jupiter. (ii) Titan's thick atmosphere and volatile surface cause it to respond to major impacts in an Earth-like manner. The impact that made Menrva - the 440 km diameter impact basin sited near the current apex of Titan's motion - was big enough to raise the average global surface temperature above 273 K, which suggests that water rain was possible. This would have been followed by methane drizzles lasting for thousands of years. More modest impacts will generate crater lakes and will saturate the atmosphere with methane, the latter leading to hundreds of years of intermittent drizzle. (iii) Impact ejecta from Menrva will strike Hyperion and should saturate the latter with sesquinary craters. (iv) In any modern story of how Titan got its atmosphere, solar nebular condensates (comets) deliver the volatiles. A consequence of a cometogenic atmosphere is that the atmosphere is heavily processed by strong shocks. The high temperatures produce a wide range of chemical species that would not otherwise be abundant. Some of these will survive to mix into the atmosphere (e.g., CO) or freeze out to fall to the surface (e.g. CO2). (v) That Titan even has an atmosphere, when Callisto and Ganymede do not, is an excellent question. The leading explanation is that Titan alone was made from ammonia - and methane - rich stuff. But the competition between impact delivery and impact expulsion of volatiles can strongly favor Titan over Callisto. Stable isotopes as well as total volatile inventories provide constraints.

Reflecting on the Japan-Chile Task-Based Telecollaboration Project for Beginner-Level Learners

ERIC Educational Resources Information Center

Dunne, B. Greg

2014-01-01

Using O'Dowd and Ritter's (2006) Inventory of Reasons for Failed Communication in Telecollaborative Projects as a barometer, this article details the considerations and procedures followed in a task-based, asynchronous email telecollaboration project between EFL (English as a Foreign Language) learners in Japan and Chile. In a climate where…

Titan's Interior Chemical Composition: Possible Important Phase Transitions

NASA Astrophysics Data System (ADS)

Howard, Michael; Fried, L. E.; Khare, B. N.; McKay, C. P.

2008-09-01

We study the interior composition of Titan using thermal chemical equilibrium calculations that are valid to high pressures and temperatures. The equations of state are based on exponential-6 fluid theory and have been validated against experimental data up to a few Mbars in pressure and approximately 20000K in temperature. In addition to CHNO molecules, we account for multi-phases of carbon, water and a variety of metals such as Al and Fe, and their oxides. With these fluid equations of state, chemical equilibrium is calculated for a set of product species. As the temperature and pressure evolves for increasing depth in the interior, the chemical equilibrium shifts. We assume that Titan is initially composed of comet material, which we assume to be solar, except for hydrogen, which we take to be depleted by a factor 1/1000. We find that a significant amount of nitrogen is in the form of N2, rather than NH3. Moreover, above 12 kbars pressure, as is the interior pressure of Titan, a significant amount of the carbon is in the form of graphite, rather than CO2 and CH4. We discuss the implications of these results for understanding the atmospheric and surface composition of Titan. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Titan after Cassini Huygens

NASA Astrophysics Data System (ADS)

Beauchamp, P. M.; Lunine, J.; Lebreton, J.; Coustenis, A.; Matson, D.; Reh, K.; Erd, C.

2008-12-01

In 2005, the Huygens Probe gave us a snapshot of a world tantalizingly like our own, yet frozen in its evolution on the threshold of life. The descent under parachute, like that of Huygens in 2005, is happening again, but this time in the Saturn-cast twilight of winter in Titan's northern reaches. With a pop, the parachute is released, and then a muffled splash signals the beginning of the first floating exploration of an extraterrestrial sea-this one not of water but of liquid hydrocarbons. Meanwhile, thousands of miles away, a hot air balloon, a "montgolfiere," cruises 6 miles above sunnier terrain, imaging vistas of dunes, river channels, mountains and valleys carved in water ice, and probing the subsurface for vast quantities of "missing" methane and ethane that might be hidden within a porous icy crust. Balloon and floater return their data to a Titan Orbiter equipped to strip away Titan's mysteries with imaging, radar profiling, and atmospheric sampling, much more powerful and more complete than Cassini was capable of. This spacecraft, preparing to enter a circular orbit around Saturn's cloud-shrouded giant moon, has just completed a series of flybys of Enceladus, a tiny but active world with plumes that blow water and organics from the interior into space. Specialized instruments on the orbiter were able to analyze these plumes directly during the flybys. Titan and Enceladus could hardly seem more different, and yet they are linked by their origin in the Saturn system, by a magnetosphere that sweeps up mass and delivers energy, and by the possibility that one or both worlds harbor life. It is the goal of the NASA/ESA Titan Saturn System Mission (TSSM) to explore and investigate these exotic and inviting worlds, to understand their natures and assess the possibilities of habitability in this system so distant from our home world. Orbiting, landing, and ballooning at Titan represent a new and exciting approach to planetary exploration. The TSSM mission

Activities of the US-Japan Safety Monitor Joint Working Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richard L. Savercool; Lee C. Cadwallader

2004-09-01

This paper documents the activities of the US-Japan exchange in the area of personnel safety at magnetic and laser fusion experiments. A near-miss event with a visiting scientist to the US in 1992 was the impetus for forming the Joint Working Group on Fusion Safety. This exchnge has been under way for over ten years and has provided many safety insights for both US and Japanese facility personnel at national institutes and at universities. The background and activities of the Joint Working Group are described, including the facilities that have been visited for safety walkthroughs, the participants from both countries,more » and the main safety issues examined during visits. Based on these visits, some operational safety ideas to enhance experiment safety are given. The near-term future plans of the Safety Monitor Joint Working group are also discussed.« less

Titan's highly variable plasma environment

NASA Astrophysics Data System (ADS)

Wolf, D. A.; Neubauer, F. M.

1982-02-01

It is noted that Titan's plasma environment is variable for two reasons. The variability of the solar wind is such that Titan may be located in the outer magnetosphere, the magnetosheath, or the interplanetary medium around noon Saturnian local time. What is more, there are local time variations in Saturn's magnetosphere. The location of the stagnation point of Saturn's magnetosphere is calculated, assuming a terrestrial type magnetosphere. Characteristic plasma parameters along the orbit of Titan are shown for high solar wind pressure. During crossings of the Saturnian magnetopause or bow shock by Titan, abrupt changes in the flow direction and stagnation pressure are expected, as are rapid associated changes in Titan's uppermost atmosphere.

The Possibilities and Challenges in Missions to Europa and Titan for Exploration and as a Stepping Stone to Mankind

NASA Astrophysics Data System (ADS)

Ganapathy, Rohan M.

This enthusiastic project describes a long-term development plan to enable human exploration of the outer solar system, with a focus on Europa and Titan. These are two of the most interesting moons of Jupiter and Saturn, respectively, because they are the places in the solar system with the greatest potential for harboring extraterrestrial life. Since human expeditions to these worlds are considered impossible with current capabilities, the proposal of a well-organized sequence of steps towards making this a reality is formulated. The project includes the necessary development strategies in key scientic and technological areas that are essential for identifying the requirements for the exploration of the outer planetary moons. Some of the topics that are analyzed throughout the project plan include: scientic observations at Europa and Titan, advanced propulsion and nuclear power systems, in-situ resource utilization, radiation mitigation techniques, closed life support systems, habitation for long-term space flight, and artificial gravity. In addition to the scientic and technological aspects of this project, it is recognized that before any research and development work may begin, some level of program management must be established. Within this paper, legal issues, national and international policy, motivation, organization and management, economic considerations, outreach, education, ethics, and social implications are all considered with respect to possible future scenarios which enable human missions to the outer solar system. This project illustrates how such accomplishments could influence a mission to Europa to search for evidence of life in its subsurface oceans. The future remains unpredictable, as does the realization of any of these possibilities. However, projects such as this remind us that the final frontier for humans is truly outer space, and only our imagination will determine where the frontier stops. We can dream of visiting other planetary

Titan's organic chemistry

NASA Technical Reports Server (NTRS)

Sagan, C.; Thompson, W. R.; Khare, B. N.

1985-01-01

Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of the simulated Titanian atmosphere, are consistent with measured properties of Titan from ultraviolet to microwave frequencies and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on earth. At least 100-m, and possibly kms thicknesses of complex organics have been produced on Titan during the age of the solar system, and may exist today as submarine deposits beneath an extensive ocean of simple hydrocarbons.

Co-crystal formation between two organic solids on the surface of Titan

NASA Astrophysics Data System (ADS)

Cable, M. L.; Vu, T. H.; Maynard-Casely, H. E.; Hodyss, R. P.

2017-12-01

Laboratory experiments of Titan molecular materials, informed by modeling, can help us to understand the complex and dynamic surface processes occurring on this moon at cryogenic temperatures. We previously demonstrated that two common organic materials on Titan, ethane and benzene, form a unique and stable co-crystalline structure at Titan surface temperatures. We have now characterized a second co-crystal that is stable on Titan, this time between two solids: acetylene and ammonia. The co-crystal forms within minutes at Titan surface temperature, as evidenced by new Raman spectral features in the lattice vibration and C-H bending regions. In addition, a red shift of the C-H stretching mode suggests that the acetylene-ammonia co-crystal is stabilized by a network of C-H···N interactions. Thermal stability studies indicate that this co-crystal remains intact to >110 K, and experiments with liquid methane and ethane reveal the co-crystal to be resistant to fluvial or pluvial exposure. Non-covalently bound structures such as these co-crystals point to far more complex surface interactions than previously believed on Titan. New physical and mechanical properties (deformation, plasticity, density, etc.), differences in storage of key species (i.e., ethane versus methane), variations in surface transport and new chemical gradients can all result in diverse surface features and chemistries of astrobiological interest.

Joint observations of Titan's North Pole by Cassini/VIMS and Keck/NIRSPEC

NASA Astrophysics Data System (ADS)

Sotin, C.; Griffith, C. A.; Fitzpatrick, R.; Lawrence, K. J.

2017-12-01

One of many Titan's characteristics is the presence of hydrocarbon seas and lakes in the Northern hemisphere, which represent one reservoir involved in the methane cycle that controls Titan's meteorology. During Titan's spring, the North Pole is illuminated and evaporation of methane should happen. Observations of the non-saturated absorption bands in the 1.6 micron atmospheric window by the NIRSPEC (Near Infrared Spectrometer) instrument on the Keck telescope should allow us to retrieve this critical information to understand the methane cycle on Titan. Such observations were performed during the night of July 9, 2017. Simultaneously, images of Titan's North pole were taken by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft during non-targeted flybys between 7:00 am and 8:45 am UT on July 10, 2017. As observed during recent non-targeted flybys, cloud activity at high northern latitudes is increasing as Titan gets closer to summer solstice. During Rev 283, elongated clouds form a circle along latitude 60 N (green arrow) with an apparent higher activity around 90W (blue arrow). There is also a bright patch at the North Pole (red arrow) that is visible at 2.1 micron and not at 2.0 micron, which also suggests cloud activity. Analysis of the 1.6 micron atmospheric window will be presented while the processing of the NIRSPEC data are ongoing.

Cassini/Huygens Investigations of Titan's Methane Cycle

NASA Astrophysics Data System (ADS)

Griffith, C. A.; Penteado, P.

2008-12-01

In Titan's atmosphere, the second most abundant constituent, methane, exists as a gas, liquid and solid, and cycles between the atmosphere and surface. Similar to Earth's hydrological cycle, Titan sports clouds, rain, and lakes. Yet, Titan's cycle differs dramatically from its terrestrial counterpart, and reveals the workings of weather in an atmosphere that is ten times thicker than Earth's atmosphere, that is two orders of magnitude less illuminated, and that involves a different condensable. Measurements of Titan's troposphere, where the methane cycle plays out, are limited largely to spectral images of Titan's clouds, several temperature profiles by Voyager, Huygens and Cassini, recent Keck spectra of the surface methane humidity, and one vertical profile of Titan's methane abundance, measured on a summer afternoon in Titan's tropical atmosphere by the Huygens probe. The salient features of Titan's methane cycle are distinctly alien: clouds have predominated the northern and southern polar atmospheres; the one humidity profile precisely matches the profile (of cartoonish simplicity) used in pre-Cassini models, and surface features correlate with latitude. Data of Titan's troposphere are analyzed with thermodynamic and radiative transfer calculations, and synthesized with other studies of Titan's stratosphere and surface, to investigate the workings of Titan's methane cycle. At the end of Cassini's nominal mission, we find that Titan's weather, climate and surface-to-atmosphere exchange of volatiles vastly differs from the manifestation of these processes on Earth, largely as a result of different basic characteristics of these planetary bodies. The talk ends with a comparison between Titan and Earth's tropospheres, their fundamental properties, the energetics of their condensible cycles, their weather and climates. References: Griffith C.A. et al. Titan's Tropical Storms in an Evolving Atmosphere. Ap.J. In Press (2008). Griffith C.A. Storms, Polar Deposits, and

Highlighting Titan's Hazes

NASA Image and Video Library

2017-08-11

NASA's Cassini spacecraft looks toward the night side of Saturn's moon Titan in a view that highlights the extended, hazy nature of the moon's atmosphere. During its long mission at Saturn, Cassini has frequently observed Titan at viewing angles like this, where the atmosphere is backlit by the Sun, in order to make visible the structure of the hazes. Titan's high-altitude haze layer appears blue here, whereas the main atmospheric haze is orange. The difference in color could be due to particle sizes in the haze. The blue haze likely consists of smaller particles than the orange haze. Images taken using red, green and blue spectral filters were combined to create this natural-color view. The image was taken with the Cassini spacecraft narrow-angle camera on May 29, 2017. The view was acquired at a distance of approximately 1.2 million miles (2 million kilometers) from Titan. Image scale is 5 miles (9 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21625

Peering Through Titan Haze

NASA Image and Video Library

2015-12-04

This composite image shows an infrared view of Saturn's moon Titan from NASA's Cassini spacecraft, acquired during the mission's "T-114" flyby on Nov. 13, 2015. The spacecraft's visual and infrared mapping spectrometer (VIMS) instrument made these observations, in which blue represents wavelengths centered at 1.3 microns, green represents 2.0 microns, and red represents 5.0 microns. A view at visible wavelengths (centered around 0.5 microns) would show only Titan's hazy atmosphere (as in PIA14909). The near-infrared wavelengths in this image allow Cassini's vision to penetrate the haze and reveal the moon's surface. During this Titan flyby, the spacecraft's closest-approach altitude was 6,200 miles (10,000 kilometers), which is considerably higher than those of typical flybys, which are around 750 miles (1,200 kilometers). The high flyby allowed VIMS to gather moderate-resolution views over wide areas (typically at a few kilometers per pixel). The view looks toward terrain that is mostly on the Saturn-facing hemisphere of Titan. The scene features the parallel, dark, dune-filled regions named Fensal (to the north) and Aztlan (to the south), which form the shape of a sideways letter "H." Several places on the image show the surface at higher resolution than elsewhere. These areas, called subframes, show more detail because they were acquired near closest approach. They have finer resolution, but cover smaller areas than data obtained when Cassini was farther away from Titan. Near the limb at left, above center, is the best VIMS view so far of Titan's largest confirmed impact crater, Menrva (first seen by the RADAR instrument in PIA07365). Similarly detailed subframes show eastern Xanadu, the basin Hotei Regio, and channels within bright terrains east of Xanadu. (For Titan maps with named features see http://planetarynames.wr.usgs.gov/Page/TITAN/target.) Due to the changing Saturnian seasons, in this late northern spring view, the illumination is significantly

Titan's atmosphere and climate

NASA Astrophysics Data System (ADS)

Hörst, S. M.

2017-03-01

Titan is the only moon with a substantial atmosphere, the only other thick N2 atmosphere besides Earth's, the site of extraordinarily complex atmospheric chemistry that far surpasses any other solar system atmosphere, and the only other solar system body with stable liquid currently on its surface. The connection between Titan's surface and atmosphere is also unique in our solar system; atmospheric chemistry produces materials that are deposited on the surface and subsequently altered by surface-atmosphere interactions such as aeolian and fluvial processes resulting in the formation of extensive dune fields and expansive lakes and seas. Titan's atmosphere is favorable for organic haze formation, which combined with the presence of some oxygen-bearing molecules indicates that Titan's atmosphere may produce molecules of prebiotic interest. The combination of organics and liquid, in the form of water in a subsurface ocean and methane/ethane in the surface lakes and seas, means that Titan may be the ideal place in the solar system to test ideas about habitability, prebiotic chemistry, and the ubiquity and diversity of life in the universe. The Cassini-Huygens mission to the Saturn system has provided a wealth of new information allowing for study of Titan as a complex system. Here I review our current understanding of Titan's atmosphere and climate forged from the powerful combination of Earth-based observations, remote sensing and in situ spacecraft measurements, laboratory experiments, and models. I conclude with some of our remaining unanswered questions as the incredible era of exploration with Cassini-Huygens comes to an end.

Cancer incidence and incidence rates in Japan in 2009: a study of 32 population-based cancer registries for the Monitoring of Cancer Incidence in Japan (MCIJ) project.

PubMed

Hori, Megumi; Matsuda, Tomohiro; Shibata, Akiko; Katanoda, Kota; Sobue, Tomotaka; Nishimoto, Hiroshi

2015-09-01

The Japan Cancer Surveillance Research Group aimed to estimate the cancer incidence in Japan in 2009 based on data collected from 32 of 37 population-based cancer registries, as part of the Monitoring of Cancer Incidence in Japan (MCIJ) project. The incidence of only primary invasive cancer in Japan for 2009 was estimated to be 775 601. Stomach cancer and breast cancer were the leading types of cancer in males and females, respectively. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Possible formation of amino acid precursors in the lower atmosphere of Titan

NASA Astrophysics Data System (ADS)

Kobayashi, K.; Taniuchi, T.; Kaneko, T.; Al-Hanbali, H.; Yamori, A.; Miyakawa, S.; Takano, Y.

Titan is a quite interesting satellite of Saturn from the point of view of astrobiology and origins of life It has ca 0 15 MPa atmosphere mainly composed of nitrogen and methane which can give us the possible implication of primitive Earth environments There have been a great number of experiments simulating chemical reactions in Titan atmosphere In most experiments electric discharges and ultraviolet light were used as energy sources The former is simulation of charged particles trapped in Saturn s magnetosphere and the latter is simulation of solar light Thus it can be said that these experiments simulate chemical reaction in the upper thin atmosphere Cosmic rays are another possible energy source available in Titan atmosphere Their energy is so high that they can penetrate into the lower atmosphere of Titan The energy flux of cosmic rays in the lower Titan atmosphere was estimated as to 9 0 x 10 -3 erg cm -2 s -1 Sagan and Thompson 1984 In order to simulate the action of cosmic rays in Titan atmosphere we irradiated simulated Titan atmosphere with high-energy protons A gas mixture of methane 1-10 and nitrogen balance total pressure was 700 Torr was sealed in a Pyrex tube with a window of Havar foil 0 01 mm thick It was irradiated with 3 MeV protons from a van de Graaff accelerator Tokyo Institute of Technology The products were dissolved in water dichloromethane tetrahydrofuran or benzene They were evaporated to dryness and then acid-hydrolyzed Amino acids were analyzed by cation exchange HPLC

Titan's Methane Cycle is Closed

NASA Astrophysics Data System (ADS)

Hofgartner, J. D.; Lunine, J. I.

2013-12-01

Doppler tracking of the Cassini spacecraft determined a polar moment of inertia for Titan of 0.34 (Iess et al., 2010, Science, 327, 1367). Assuming hydrostatic equilibrium, one interpretation is that Titan's silicate core is partially hydrated (Castillo-Rogez and Lunine, 2010, Geophys. Res. Lett., 37, L20205). These authors point out that for the core to have avoided complete thermal dehydration to the present day, at least 30% of the potassium content of Titan must have leached into an overlying water ocean by the end of the core overturn. We calculate that for probable ammonia compositions of Titan's ocean (compositions with greater than 1% ammonia by weight), that this amount of potassium leaching is achievable via the substitution of ammonium for potassium during the hydration epoch. Formation of a hydrous core early in Titan's history by serpentinization results in the loss of one hydrogen molecule for every hydrating water molecule. We calculate that complete serpentinization of Titan's core corresponds to the release of more than enough hydrogen to reconstitute all of the methane atoms photolyzed throughout Titan's history. Insertion of molecular hydrogen by double occupancy into crustal clathrates provides a storage medium and an opportunity for ethane to be converted back to methane slowly over time--potentially completing a cycle that extends the lifetime of methane in Titan's surface atmosphere system by factors of several to an order of magnitude over the photochemically-calculated lifetime.

Titan Mystery Clouds

NASA Image and Video Library

2016-12-21

This comparison of two views from NASA's Cassini spacecraft, taken fairly close together in time, illustrates a peculiar mystery: Why would clouds on Saturn's moon Titan be visible in some images, but not in others? In the top view, a near-infrared image from Cassini's imaging cameras, the skies above Saturn's moon Titan look relatively cloud free. But in the bottom view, at longer infrared wavelengths, Cassini sees a large field of bright clouds. Even though these views were taken at different wavelengths, researchers would expect at least a hint of the clouds to show up in the upper image. Thus they have been trying to understand what's behind the difference. As northern summer approaches on Titan, atmospheric models have predicted that clouds will become more common at high northern latitudes, similar to what was observed at high southern latitudes during Titan's late southern summer in 2004. Cassini's Imaging Science Subsystem (ISS) and Visual and Infrared Mapping Spectrometer (VIMS) teams have been observing Titan to document changes in weather patterns as the seasons change, and there is particular interest in following the onset of clouds in the north polar region where Titan's lakes and seas are concentrated. Cassini's "T120" and "T121" flybys of Titan, on June 7 and July 25, 2016, respectively, provided views of high northern latitudes over extended time periods -- more than 24 hours during both flybys. Intriguingly, the ISS and VIMS observations appear strikingly different from each other. In the ISS observations (monochrome image at top), surface features are easily identifiable and only a few small, isolated clouds were detected. In contrast, the VIMS observations (color image at bottom) suggest widespread cloud cover during both flybys. The observations were made over the same time period, so differences in illumination geometry or changes in the clouds themselves are unlikely to be the cause for the apparent discrepancy: VIMS shows persistent

A green synthesis of a layered titanate, potassium lithium titanate; lower temperature solid-state reaction and improved materials performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogawa, Makoto, E-mail: waseda.ogawa@gmail.com; Department of Earth Sciences, Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050; Morita, Masashi, E-mail: m-masashi@y.akane.waseda.jp

2013-10-15

A layered titanate, potassium lithium titanate, with the size range from 0.1 to 30 µm was prepared to show the effects of the particle size on the materials performance. The potassium lithium titanate was prepared by solid-state reaction as reported previously, where the reaction temperature was varied. The reported temperature for the titanate preparation was higher than 800 °C, though 600 °C is good enough to obtain single-phase potassium lithium titanate. The lower temperature synthesis is cost effective and the product exhibit better performance as photocatalysts due to surface reactivity. - Graphical abstract: Finite particle of a layered titanate, potassiummore » lithium titanate, was prepared by solid-state reaction at lower temperature to show modified materials performance. Display Omitted - Highlights: • Potassium lithium titanate was prepared by solid-state reaction. • Lower temperature reaction resulted in smaller sized particles of titanate. • 600 °C was good enough to obtain single phased potassium lithium titanate. • The product exhibited better performance as photocatalyst.« less

Chemistry and evolution of Titan's atmosphere

NASA Technical Reports Server (NTRS)

Strobel, D. F.

1982-01-01

The chemistry and evolution of Titan's atmosphere are reviewed, in light of the scientific findings from the Voyager mission. It is argued that the present N2 atmosphere may be Titan's initial atmosphere, rather than one photochemically derived from an original NH3 atmosphere. The escape rate of hydrogen from Titan is controlled by photochemical production from hydrocarbons. CH4 is irreversibly converted to less hydrogen-rich hydrocarbons, which over geologic time accumulate on the surface to a layer thickness of about 0.5 km. Magnetospheric electrons interacting with Titan's exosphere may dissociate enough N2 into hot, escaping N atoms to remove about 0.2 of Titan's present atmosphere over geologic time. The energy dissipation of magnetospheric electrons exceeds solar EUV energy deposition in Titan's atmosphere by an order of magnitude, and is the principal driver of nitrogen photochemistry. The environmental conditions in Titan's upper atmosphere are favorable to building up complex molecules, particularly in the north polar cap region.

Titan Polar Landscape Evolution

NASA Technical Reports Server (NTRS)

Moore, Jeffrey M.

2016-01-01

With the ongoing Cassini-era observations and studies of Titan it is clear that the intensity and distribution of surface processes (particularly fluvial erosion by methane and Aeolian transport) has changed through time. Currently however, alternate hypotheses substantially differ among specific scenarios with respect to the effects of atmospheric evolution, seasonal changes, and endogenic processes. We have studied the evolution of Titan's polar region through a combination of analysis of imaging, elevation data, and geomorphic mapping, spatially explicit simulations of landform evolution, and quantitative comparison of the simulated landscapes with corresponding Titan morphology. We have quantitatively evaluated alternate scenarios for the landform evolution of Titan's polar terrain. The investigations have been guided by recent geomorphic mapping and topographic characterization of the polar regions that are used to frame hypotheses of process interactions, which have been evaluated using simulation modeling. Topographic information about Titan's polar region is be based on SAR-Topography and altimetry archived on PDS, SAR-based stereo radar-grammetry, radar-sounding lake depth measurements, and superposition relationships between geomorphologic map units, which we will use to create a generalized topographic map.

Dark and Light Titan

NASA Image and Video Library

2010-09-08

NASA Cassini spacecraft examines Titan dark and light seasonal hemispheric dichotomy as it images the moon with a filter sensitive to near-infrared light. This image also shows Titan north polar hood.

Simulating Titan's aerosols in a three dimensional general circulation model

NASA Astrophysics Data System (ADS)

Larson, Erik J. L.; Toon, Owen B.; Friedson, Andrew J.

2014-11-01

We present results from a new three dimensional GCM with a complete microphysics treatment of the aerosols. We used the Titan Community Atmospheres Model (CAM), to which we have coupled the Community Aerosol and Radiation Model for Atmospheres (CARMA). This model was unable to reproduce superrotating winds without an ad hoc forcing of the zonal winds. Our model was validated by comparing the extinction, optical depth, phase functions, and number densities with data from Cassini and Huygens, as well as other space based and ground based observations. These comparisons allowed us to constrain the microphysical properties of Titan's haze in the tropics at the time of the Huygens descent. Our best fit of the free aerosol parameters include a haze production rate of 1 × 10-14 g cm-2 s-1 and a charge to radius ratio on the particles of 7.5 e-/μm. Despite recent evidence of equatorial precipitation on Titan, we find the aerosols are only slowly removed by rainfall, less than once in 50 Earth years. One way to fit the wavelength dependence of the optical depth is to model the haze as fractal particles with a changing fractal dimension of 2 above 80 km that increases to 2.8 below 30 km. We investigate the spatial and seasonal variability of Titan's haze in our model. We find that the haze particle size and number density responds to the dynamics and creates a seasonal cycle in Titan's albedo.

US Climate Variability and Predictability Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patterson, Mike

The US CLIVAR Project Office administers the US CLIVAR Program with its mission to advance understanding and prediction of climate variability and change across timescales with an emphasis on the role of the ocean and its interaction with other elements of the Earth system. The Project Office promotes and facilitates scientific collaboration within the US and international climate and Earth science communities, addressing priority topics from subseasonal to centennial climate variability and change; the global energy imbalance; the ocean’s role in climate, water, and carbon cycles; climate and weather extremes; and polar climate changes. This project provides essential one-year supportmore » of the Project Office, enabling the participation of US scientists in the meetings of the US CLIVAR bodies that guide scientific planning and implementation, including the scientific steering committee that establishes program goals and evaluates progress of activities to address them, the science team of funded investigators studying the ocean overturning circulation in the Atlantic, and two working groups tackling the priority research topics of Arctic change influence on midlatitude climate and weather extremes and the decadal-scale widening of the tropical belt.« less

Exploration of a New World: Saturn's Moon Titan

NASA Astrophysics Data System (ADS)

Hansen, Candice; Ray, Trina; Matson, Dennis L.; Lebreton, Jean-Pierre; Waite, J. Hunter; Turtle, Elizabeth; Bolton, Scott; Spilker, Linda

Before the Cassini-Huygens spacecraft arrived at the Saturnian system very little was known about Saturn's largest moon Titan. Ground-based observations and Voyager data had revealed a thick atmosphere composed primarily of nitrogen with a small percentage of methane and higher order hydrocarbons. The surface was obscured by hydrocarbon smog. Where do you begin, when exploring a new world? What were the basic science objectives? What were the exploration objectives? How well has Cassini-Huygens achieved them? What are the pragmatic considerations in using a spacecraft equipped with 12 sophisticated instruments and no moving parts? How were the 45 Titan flybys in the primary mission to be used? We started by organizing science goals into four high level disciplines for the orbital investigation from Cassini: 1) study of the interior, 2) mapping of the surface geology and composition, 3) study of atmospheric structure, composition and dynamics, and 4) characterization of Titan's interaction with Saturn's magnetosphere. The Huygens probe gave us detailed in situ "ground truth" from the upper atmosphere to the surface, for comparison to orbital data. Now at the end of the primary mission, we are embarking on Cassini's 2 year "Equinox" extended mission, and planning a possible 6 year Cassini "Solstice" Mission to follow if all goes well. When we arrived at Titan it was the equivalent of January and by the time the Solstice Mission is complete it will be June on Titan. Now is a good time to review our progress and our future goals for the exploration of Titan. For each of the four disciplines we will review the goals and achievements of the primary mission, the way in which the 26 Titan flybys in the 2 year Equinox mission fills in gaps left by the primary mission, and look ahead to what could be done in a Solstice Mission. Cassini has discovered seas of "sand" dunes, lakes in the polar regions, and a young surface marked by few craters. The blank spots on the map are

Untangling the Chemical Evolution of Titan's Atmosphere and Surface -- From Homogeneous to Heterogeneous Chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaiser, Ralf I.; Maksyutenko, Pavlo; Ennis, Courtney

The arrival of the Cassini-Huygens probe at Saturn's moon Titan - the only Solar System body besides Earth and Venus with a solid surface and a thick atmosphere with a pressure of 1.4 atm at surface level - in 2004 opened up a new chapter in the history of Solar System exploration. The mission revealed Titan as a world with striking Earth-like landscapes involving hydrocarbon lakes and seas as well as sand dunes and lava-like features interspersed with craters and icy mountains of hitherto unknown chemical composition. The discovery of a dynamic atmosphere and active weather system illustrates further themore » similarities between Titan and Earth. The aerosol-based haze layers, which give Titan its orange-brownish color, are not only Titan's most prominent optically visible features, but also play a crucial role in determining Titan's thermal structure and chemistry. These smog-like haze layers are thought to be very similar to those that were present in Earth's atmosphere before life developed more than 3.8 billion years ago, absorbing the destructive ultraviolet radiation from the Sun, thus acting as 'prebiotic ozone' to preserve astrobiologically important molecules on Titan. Compared to Earth, Titan's low surface temperature of 94 K and the absence of liquid water preclude the evolution of biological chemistry as we know it. Exactly because of these low temperatures, Titan provides us with a unique prebiotic 'atmospheric laboratory' yielding vital clues - at the frozen stage - on the likely chemical composition of the atmosphere of the primitive Earth. However, the underlying chemical processes, which initiate the haze formation from simple molecules, have been not understood well to date.« less

Direct Measurement of Interparticle Forces of Titan Aerosol Analogs ("Tholin") Using Atomic Force Microscopy

NASA Astrophysics Data System (ADS)

Yu, Xinting; Hörst, Sarah M.; He, Chao; McGuiggan, Patricia; Bridges, Nathan T.

2017-12-01

To understand the origin of the dunes on Titan, it is important to investigate the material properties of Titan's organic sand particles on Titan. The organic sand may behave distinctively compared to the quartz/basaltic sand on terrestrial planets (Earth, Venus, and Mars) due to differences in interparticle forces. We measured the surface energy (through contact angle measurements) and elastic modulus (through Atomic Force Microscopy) of the Titan aerosol analog (tholin). We find that the surface energy of a tholin thin film is about 70.9 mN/m, and its elastic modulus is about 3.0 GPa (similar to hard polymers like PMMA and polystyrene). For two 20 μm diameter particles, the theoretical cohesion force is therefore 3.3 μN. We directly measured interparticle forces for relevant materials: tholin particles are 0.8 ± 0.6 μN, while the interparticle cohesion between walnut shell particles (a typical model materials for the Titan Wind Tunnel, TWT) is only 0.4 ± 0.1 μN. The interparticle cohesion forces are much larger for tholins and presumably Titan sand particles than materials used in the TWT. This suggests that we should increase the interparticle force in both analog experiments (TWT) and threshold models to correctly translate the results to real Titan conditions. The strong cohesion of tholins may also inform us how the small aerosol particles (˜1 μm) in Titan's atmosphere are transformed into large sand particles (˜200 μm). It may also support the cohesive sand formation mechanism suggested by Rubin and Hesp (2009), where only unidirectional wind is needed to form linear dunes on Titan.

Comet Impacts as a Source of Methane on Titan

NASA Astrophysics Data System (ADS)

Howard, Michael; Goldman, N.; Vitello, P. A.

2006-12-01

We model comet impacts on Titan as a possible source of atmospheric methane. That is, we study the formation of methane in comet impacts using chemical equilibrium calculations coupled with arbitrary Lagrange-Eulerian (ALE) hydrodynamics. That is, we study the chemical transformation of comet material under high pressure and temperature conditions as it impacts Titan. We assume that the comet is composed of ice, graphite, nitrogen and some hydrocarbons. For certain pressure and temperature regimes, in chemical equilibrium, a significant amount of ice and graphite can be transformed into methane. As a result, we find that a significant amount of methane can be formed in comet collisions on Titan. The methane is formed in the post-impact vapor clouds that form as the comet material expands and cools. We use molecular dynamics to construct an equation of state for the ice surface structures and the comet material. We also study kinetic processes for methane formation during the expansion and cooling phase. We discuss the implication of our results for comets as a possible source of abiotic methane on Titan and its implications on the origin of life. We also discuss the various uncertainties in our model. * This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

Nitrogen Chemistry in Titan's Upper Atmosphere

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; Cuzzi, Jeffrey (Technical Monitor)

1996-01-01

In Titan's upper atmosphere N2 is dissociated to N by solar UV and high energy electrons. This flux of N provides for interesting organic chemistry in the lower atmosphere of Titan. Previously the main pathway for the loss of this N was thought to be the formation of HCN, followed by diffusion of this HCN to lower altitudes leading ultimately to condensation. However, recent laboratory simulations of organic chemistry in Titan's atmosphere suggest that formation of the organic haze may be an important sink for atmospheric N. Because estimates of the eddy diffusion profile on Titan have been based on the HCN profile, inclusion of this additional sink for N will affect estimates for all transport processes in Titan's atmosphere. This and other implications of this sink for the N balance on Titan are considered.

Conserving the Giant Titans

Science.gov Websites

Virtual Herbarium Conserving the Giant Titans The gigantic and pungent Titan Arum or Corpse Flower Milonic.com Copyright © 2007 Virtual Herbarium - All rights reserved 11935 Old Cutler Road, Coral Gables, FL

Mimas...and Titan Beyond

NASA Image and Video Library

2006-01-03

Titan, Saturn largest moon and Mimas in the foreground are seen together in this view from Cassini. Titan gravity is weaker than Earth, so the moon atmosphere is quite extended -- a quality hinted at in this view

Inside Titan Author Concept

NASA Image and Video Library

2012-06-28

This artist concept shows a possible scenario for the internal structure of Titan, as suggested by data from NASA Cassini spacecraft. Scientists have been trying to determine what is under Titan organic-rich atmosphere and icy crust.

Brain/MINDS: brain-mapping project in Japan

PubMed Central

Okano, Hideyuki; Miyawaki, Atsushi; Kasai, Kiyoto

2015-01-01

There is an emerging interest in brain-mapping projects in countries across the world, including the USA, Europe, Australia and China. In 2014, Japan started a brain-mapping project called Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS). Brain/MINDS aims to map the structure and function of neuronal circuits to ultimately understand the vast complexity of the human brain, and takes advantage of a unique non-human primate animal model, the common marmoset (Callithrix jacchus). In Brain/MINDS, the RIKEN Brain Science Institute acts as a central institute. The objectives of Brain/MINDS can be categorized into the following three major subject areas: (i) structure and functional mapping of a non-human primate brain (the marmoset brain); (ii) development of innovative neurotechnologies for brain mapping; and (iii) human brain mapping; and clinical research. Brain/MINDS researchers are highly motivated to identify the neuronal circuits responsible for the phenotype of neurological and psychiatric disorders, and to understand the development of these devastating disorders through the integration of these three subject areas. PMID:25823872

Squeezing and Stretching Titan Author Concept

NASA Image and Video Library

2012-06-28

This artist concept shows tides on Titan raised by Saturn gravity, as detected by NASA Cassini spacecraft. Saturn gravitational pull on Titan, its largest moon, varies as Titan orbits along an elliptical path around the planet every 16 days.

Weather on Titan

NASA Astrophysics Data System (ADS)

Griffith, C. A.; Hall, J. L.; Geballe, T. R.

2000-10-01

Titan's atmosphere potentially sports a cycle similar to the hydrologic one on Earth with clouds, rain and seas, but with methane playing the terrestrial role of water. Over the past ten years many independent efforts indicated no strong evidence for cloudiness until some unique spectra were analyzed in 1998 (Griffith et al.). These surprising observations displayed enhanced fluxes of 14-200% on two nights at precisely the wavelengths (windows) that sense Titan's lower altitude where clouds might reside. The morphology of these enhancements in all 4 windows observed indicate that clouds covered ~6-9% of Titan's surface and existed at ~15 km altitude. Here I discuss new observations recorded in 1999 aimed to further characterize Titan's clouds. While we find no evidence for a massive cloud system similar to the one observed previously, 1%-4% fluctuations in flux occur daily. These modulations, similar in wavelength and morphology to the more pronounced ones observed earlier, suggest the presence of clouds covering <=1% of Titan's disk. The variations are too small to have been detected by most prior measurements. Repeated observations, spaced 30 minutes apart, indicate a temporal variability observable in the time scale of a couple of hours. The cloud heights hint that convection governs their evolutions. Their short lives point to the presence of rain. C. A. Griffith and J. L. Hall are supported by the NASA Planetary Astronomy Program NAG5-6790.

Titanic: A Statistical Exploration.

ERIC Educational Resources Information Center

Takis, Sandra L.

1999-01-01

Uses the available data about the Titanic's passengers to interest students in exploring categorical data and the chi-square distribution. Describes activities incorporated into a statistics class and gives additional resources for collecting information about the Titanic. (ASK)

Magnetospheric particle precipitation at Titan

NASA Astrophysics Data System (ADS)

Royer, Emilie; Esposito, Larry; Crary, Frank; Wahlund, Jan-Erik

2017-04-01

Although solar XUV radiation is known to be the main source of ionization in Titan's upper atmosphere around 1100 km of altitude, magnetospheric particle precipitation can also account for about 10% of the ionization process. Magnetospheric particle precipitation is expected to be the most intense on the nightside of the satelllite and when Titan's orbital position around Saturn is the closest to Noon Saturn Local Time (SLT). In addition, on several occasion throughout the Cassini mission, Titan has been observed while in the magnetosheath. We are reporting here Ultraviolet (UV) observations of Titan airglow enhancements correlated to these magnetospheric changing conditions occurring while the spacecraft, and thus Titan, are known to have crossed Saturn's magnetopause and have been exposed to the magnetosheath environnment. Using Cassini-Ultraviolet Imaging Spectrograph (UVIS) observations of Titan around 12PM SLT as our primary set of data, we present evidence of Titan's upper atmosphere response to a fluctuating magnetospheric environment. Pattern recognition software based on 2D UVIS detector images has been used to retrieve observations of interest, looking for airglow enhancement of a factor of 2. A 2D UVIS detector image, created for each UVIS observation of Titan, displays the spatial dimension of the UVIS slit on the x-axis and the time on the y-axis. In addition, data from the T32 flyby and from April 17, 2005 from in-situ Cassini instruments are used. Correlations with data from simultaneous observations of in-situ Cassini instruments (CAPS, RPWS and MIMI) has been possible on few occasions and events such as electron burst and reconnections can be associated with unusual behaviors of the Titan airglow. CAPS in-situ measurements acquired during the T32 flyby are consistent with an electron burst observed at the spacecraft as the cause of the UV emission. Moreover, on April 17, 2005 the UVIS observation displays feature similar to what could be aTitan

The Titan Sky Simulator ™ - Testing Prototype Balloons in Conditions Approximating those in Titan's Atmosphere

NASA Astrophysics Data System (ADS)

Nott, Julian

This paper will describe practical work flying prototype balloons in the "The Titan Sky Simulator TM " in conditions approximating those found in Titan's atmosphere. Saturn's moon, Titan, is attracting intense scientific interest. This has led to wide interest in exploring it with Aerobots, balloons or airships. Their function would be similar to the Rovers exploring Mars, but instead of moving laboriously across the rough terrain on wheels, they would float freely from location to location. To design any balloon or airship it is essential to know the temperature of the lifting gas as this influences the volume of the gas, which in turn influences the lift. To determine this temperature it is necessary to know how heat is transferred between the craft and its surroundings. Heat transfer for existing balloons is well understood. However, Titan conditions are utterly different from those in which balloons have ever been flown, so heat transfer rates cannot currently be calculated. In particular, thermal radiation accounts for most heat transfer for existing balloons but over Titan heat transfer will be dominated by convection. To be able to make these fundamental calculations, it is necessary to get fundamental experimental data. This is being obtained by flying balloons in a Simulator filled with nitrogen gas at very low temperature, about 95° K / minus 180° C, typical of Titan's temperatures. Because the gas in the Simulator is so cold, operating at atmospheric pressure the density is close to that of Titan's atmosphere. "The Titan Sky Simulator TM " has an open interior approximately 4.5 meter tall and 2.5 meters square. It has already been operated at 95° K/-180° C. By the time of the Conference it is fully expected to have data to present from actual balloons flying at this temperature. Perhaps the most important purpose of this testing is to validate numerical [computational fluid dynamics] models being developed by Tim Colonius of Caltech. These numerical

INMS Titan Observations

NASA Astrophysics Data System (ADS)

Waite, J. H., Jr.; Niemann, H.; Yelle, R. V.; Kasprzak, W. T.; Cravens, T. E.; Luhmann, J. G.; McNutt, R. L.; Ip, W.-H.; De La Haye, V.; Ledvina, S.; Mueller-Wordarg, I.; Borggren, N.

2005-08-01

The Ion Neutral Mass Spectrometer (INMS) aboard the Cassini Orbiter has obtained the first in situ composition measurements of the neutral densities of molecular nitrogen, methane, hydrogen, argon, and a host of stable carbon-nitrile ion and neutral compounds in the first and sixth flybys of Titan. The bulk composition and thermal structure of the moon's upper atmosphere appear to vary with latitude and local time. The new data set provides strong evidence for atmospheric waves in the upper atmosphere and for the existence of a warm, chemically complex corona. Furthermore, the data set provides direct measurements of isotopes of nitrogen, carbon, and argon, which reveal interesting clues about the evolution of the atmosphere. The atmosphere likely formed from outgassing as planetesimals composed of silicates, water ice, clathrates of methane, and ammonia hydrates coalesced. Subsequent photochemistry and/or shock-induced chemistry likely converted the atmospheric nitrogen into molecular nitrogen, which is inferred by the absence (<0.6 ppm) of 36Ar in the INMS data. (Ice clathrate delivery of N2 would have presumably also delivered 36Ar to the proto Titan.) The decrease of the 14N to 15N isotopic ratio with respect to the terrestrial value allows us to suggest an early atmosphere >1.5 to 100 times more substantial that was lost via escape over the intervening 4.5 billion years. Carbon in the form of methane has continued to outgas over time from the interior (as inferred from the elevated 12C to 13C ratio as compared to terrestrial values) with much of its subsequent photolysis products being deposited in the form of complex hydrocarbons on the surface ( 5 x 1027 s-1 as estimated from the H2 escape rate of 6.1 ± 0.2 x 109 cm-2 s-1 measured by INMS). This talk will highlight the composition, vertical structure, wave processes, and escape of Titan's atmosphere.

Cassini/VIMS observes rough surfaces on Titan's Punga Mare in specular reflection.

PubMed

Barnes, Jason W; Sotin, Christophe; Soderblom, Jason M; Brown, Robert H; Hayes, Alexander G; Donelan, Mark; Rodriguez, Sebastien; Mouélic, Stéphane Le; Baines, Kevin H; McCord, Thomas B

Cassini /VIMS high-phase specular observations of Titan's north pole during the T85 flyby show evidence for isolated patches of rough liquid surface within the boundaries of the sea Punga Mare. The roughness shows typical slopes of 6°±1°. These rough areas could be either wet mudflats or a wavy sea. Because of their large areal extent, patchy geographic distribution, and uniform appearance at low phase, we prefer a waves interpretation. Applying theoretical wave calculations based on Titan conditions our slope determination allows us to infer winds of 0.76±0.09 m/s and significant wave heights of [Formula: see text] cm at the time and locations of the observation. If correct, these would represent the first waves seen on Titan's seas, and also the first extraterrestrial sea-surface waves in general.

The atmospheric temperature structure of Titan

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Pollack, J. B.; Courtin, Regis; Lunine, Jonathan I.

1992-01-01

The contribution of various factors to the thermal structure of Titan's past and present atmosphere are discussed. A one dimensional model of Titan's thermal structure is summarized. The greenhouse effect of Titan's atmosphere, caused primarily by pressure induced opacity of N2, CH4, and H2, is discussed together with the antigreenhouse effect dominated by the haze which absorbs incident sunlight. The implications for the atmosphere of the presence of an ocean on Titan are also discussed.

Night Side of Titan

NASA Image and Video Library

1999-02-23

NASA Voyager 2 obtained this wide-angle image of the night side of Titan on Aug. 25, 1979. This is a view of Titan extended atmosphere. the bright orangish ring being caused by the atmosphere scattering of the incident sunlight.

Titan Haze is Falling

NASA Image and Video Library

2011-05-05

The change in Titan haze layer is illustrated in this figure, derived from data obtained by NASA Cassini spacecraft. The picture of Titan in panel a was taken on May 3, 2006, panel b was taken on April 2, 2010.

Titan as the Abode of Life

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.

2016-01-01

Titan is the only world we know other than Earth that has a liquid on its surface. It has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan's atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in the atmosphere. It is conceivable that H2O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic - polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the Universe is full of diverse and wondrous life forms.

Titan as the Abode of Life

NASA Astrophysics Data System (ADS)

McKay, Christopher P.

2016-02-01

Titan is the only world we know, other than Earth, that has a liquid on its surface. It also has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan's atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis, but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in its atmosphere. It is conceivable that H2O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures, azotosomes, in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic - polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the universe is full of diverse and wondrous life forms.

Titan as the Abode of Life.

PubMed

McKay, Christopher P

2016-02-03

Titan is the only world we know, other than Earth, that has a liquid on its surface. It also has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan's atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis, but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in its atmosphere. It is conceivable that H₂O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures, azotosomes, in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic-polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the universe is full of diverse and wondrous life forms.

Methane, Ethane, and Nitrogen Stability on Titan

NASA Astrophysics Data System (ADS)

Hanley, J.; Grundy, W. M.; Thompson, G.; Dustrud, S.; Pearce, L.; Lindberg, G.; Roe, H. G.; Tegler, S.

2017-12-01

Many outer solar system bodies are likely to have a combination of methane, ethane and nitrogen. In particular the lakes of Titan are known to consist of these species. Understanding the past and current stability of these lakes requires characterizing the interactions of methane and ethane, along with nitrogen, as both liquids and ices. Our cryogenic laboratory setup allows us to explore ices down to 30 K through imaging, and transmission and Raman spectroscopy. Our recent work has shown that although methane and ethane have similar freezing points, when mixed they can remain liquid down to 72 K. Concurrently with the freezing point measurements we acquire transmission or Raman spectra of these mixtures to understand how the structural features change with concentration and temperature. Any mixing of these two species together will depress the freezing point of the lake below Titan's surface temperature, preventing them from freezing. We will present new results utilizing our recently acquired Raman spectrometer that allow us to explore both the liquid and solid phases of the ternary system of methane, ethane and nitrogen. In particular we will explore the effect of nitrogen on the eutectic of the methane-ethane system. At high pressure we find that the ternary creates two separate liquid phases. Through spectroscopy we determined the bottom layer to be nitrogen rich, and the top layer to be ethane rich. Identifying the eutectic, as well as understanding the liquidus and solidus points of combinations of these species, has implications for not only the lakes on the surface of Titan, but also for the evaporation/condensation/cloud cycle in the atmosphere, as well as the stability of these species on other outer solar system bodies. These results will help interpretation of future observational data, and guide current theoretical models.

Titan Despeckled Montage

NASA Image and Video Library

2015-02-12

This montage of Cassini Synthetic Aperture Radar (SAR) images of the surface of Titan shows four examples of how a newly developed technique for handling noise results in clearer, easier to interpret views. The top row of images was produced in the manner used since the mission arrived in the Saturn system a decade ago; the row at bottom was produced using the new technique. The three leftmost image pairs show bays and spits of land in Ligea Mare, one of Titan's large hydrocarbon seas. The rightmost pair shows a valley network along Jingpo Lacus, one of Titan's larger northern lakes. North is toward the left in these images. Each thumbnail represents an area 70 miles (112 kilometers) wide. http://photojournal.jpl.nasa.gov/catalog/PIA19053

The Effects of the Japan Bridge Project on Third Graders' Cultural Sensitivity

ERIC Educational Resources Information Center

Meyer, Lindsay; Sherman, Lilian; MaKinster, James

2006-01-01

This study examines the effects of the Japan BRIDGE Project, a global education program, on its third grade participants. Characterization of lessons and analysis of student interviews were used to investigate the nature of the curriculum and whether or not student participants were more culturally sensitive due to participation. Results indicate…

Titan's Lakes in a Beaker

NASA Astrophysics Data System (ADS)

Hodyss, R. P.

2017-12-01

The surface of Titan presents a complex, varied surfaced, with mountains, plains, dunes, rivers, lakes and seas, composed of a layer of organics over a water ice bedrock. Over the past 10 years, our group at JPL has developed a variety of techniques to study the chemistry of Titan's organic surface under relevant temperature and pressure conditions (90-100 K, 1.5 bar). Dissolution, precipitation, and both covalent and non-covalent chemical processes are examined using Raman and infrared spectroscopy, mass spectrometry, optical microscopy, and synchrotron X-ray powder diffraction. Despite the low temperatures, our experiments are revealing that a rich and active organic chemistry is possible on Titan's surface. Laboratory experiments like these can provide crucial insights into the geological processes occurring Titan's surface, and help explain the wealth of observational data returned by the Cassini/Huygens mission. This type of data is also critical for the development of future missions to Titan.

Cassini Titan Science Integration: Getting a 'Jumpstart' on the Process

NASA Technical Reports Server (NTRS)

Steadman, Kimberly B.; Pitesky, Jo E.; Ray, Trina L.; Burton, Marcia E.; Alonge, Nora K.

2010-01-01

The Cassini spacecraft has been in orbit for five years, returning a wealth of scientific data from Titan and the Saturn system. The mission is a cooperative undertaking between NASA, ESA and the Italian Space Agency and the project is currently planning for a second extension of the mission. The Cassini Solstice Mission (CSM) will extend the mission's lifetime until Saturn's northern summer solstice in 2017. The Titan Orbiter Science Team (TOST) has the task of integrating the science observations for all 126 targeted Titan flybys (44 in the Prime Mission, 26 in the first extension (Equinox Mission), and 56 in the second extension (Solstice Mission)) contained in the chosen trajectory. Cassini science instruments are body-fixed with limited ability to articulate; thus, the spacecraft pointing during the flybys must be allocated among the instruments to accomplish the mission's science goals. The science that can be accomplished on each Titan flyby also critically depends on the closest approach altitude, which is in turn determined by the attitude, but changing the altitude impacts the overall trajectory for the Solstice Mission. During the Prime and Extended missions, TOST has learned that the best way to achieve Cassini's Titan science goals is via a 'jumpstart' process prior to final delivery of the trajectory. The jumpstart is driven by the desire to balance Titan science across the entire set of flybys during the CSM, and to influence any changes (tweaks) to the flyby altitudes. By the end of the jumpstart, TOST produces Master Timelines for each flyby, identifying each flyby's prime science observations and allocating control of the spacecraft attitude to specific instrument teams. In addition, developing timelines early, while the science and operations teams are still fully funded, decreases the future workload in integration and implementation.

Titan 4 TPS Replacement Implementation Study

NASA Technical Reports Server (NTRS)

Jackson, Charles H.

1996-01-01

This final report documents the overall progress of the study. It is a general discussion of the documents reviewed, recommendations, trips taken, findings/observations, and proposed corrective actions. In addition, cost data for the contract is addressed. The normal abstract and executive summary provided with most final reports is also provided as a part of this report. A conclusion section is provided that addresses the relative completeness of the Titan 4 TPSR project and this contract.

High-Speed Camera and High-Vision Camera Observations of TLEs from Jet Aircraft in Winter Japan and in Summer US

NASA Astrophysics Data System (ADS)

Sato, M.; Takahashi, Y.; Kudo, T.; Yanagi, Y.; Kobayashi, N.; Yamada, T.; Project, N.; Stenbaek-Nielsen, H. C.; McHarg, M. G.; Haaland, R. K.; Kammae, T.; Cummer, S. A.; Yair, Y.; Lyons, W. A.; Ahrns, J.; Yukman, P.; Warner, T. A.; Sonnenfeld, R. G.; Li, J.; Lu, G.

2011-12-01

The time evolution and spatial distributions of transient luminous events (TLEs) are the key parameters to identify the relationship between TLEs and parent lightning discharges, roles of electromagnetic pulses (EMPs) emitted by horizontal and vertical lightning currents in the formation of TLEs, and the occurrence condition and mechanisms of TLEs. Since the time scales of TLEs is typically less than a few milliseconds, new imaging technique that enable us to capture images with a high time resolution of < 1ms is awaited. By courtesy of "Cosmic Shore" Project conducted by Japan Broadcasting Corporation (NHK), we have carried out optical observations using a high-speed Image-Intensified (II) CMOS camera and a high-vision three-CCD camera from a jet aircraft on November 28 and December 3, 2010 in winter Japan. Using the high-speed II-CMOS camera, it is possible to capture images with 8,300 frames per second (fps), which corresponds to the time resolution of 120 us. Using the high-vision three-CCD camera, it is possible to capture high quality, true color images of TLEs with a 1920x1080 pixel size and with a frame rate of 30 fps. During the two observation flights, we have succeeded to detect 28 sprite events, and 3 elves events totally. In response to this success, we have conducted a combined aircraft and ground-based campaign of TLE observations at the High Plains in summer US. We have installed same NHK high-speed and high-vision cameras in a jet aircraft. In the period from June 27 and July 10, 2011, we have operated aircraft observations in 8 nights, and we have succeeded to capture TLE images for over a hundred events by the high-vision camera and succeeded to acquire over 40 high-speed images simultaneously. At the presentation, we will introduce the outlines of the two aircraft campaigns, and will introduce the characteristics of the time evolution and spatial distributions of TLEs observed in winter Japan, and will show the initial results of high

From Titan to the primitive Earth

NASA Astrophysics Data System (ADS)

Raulin, F.; Gpcos Team

Our knowledge of the conditions prevailing in the environment of the primitive Earth is still very limited, due to the lack of geological data. Fortunately, there are a few planetary objects in the solar system which present similarities with our planet, including during its early history. Titan is one of these. With a diameter of more than 5100 km, Titan, the largest moon of Saturn, is also the only one to have a dense atmosphere. This atmosphere, clearly evidenced by the presence of haze layers, extends to approximately 1500 km. Like the Earth, Titan's atmosphere is mainly composed of dinitrogen, N2 . The other main constituents are methane, CH4 , about 1.6% to 2.0% in the stratosphere, as measured by CIRS on Cassini and GC-MS on Huygens and dihydrogen (H2 , approximate 0.1%). With surface temperatures of approximately 94 K, and an average surface pressure of 1.5 bar, Titan's atmosphere is nearly five times denser than the Earth's. Despite of these differences between Titan and the Earth there are several analogies that can be drawn between the two planetary bodies. The first resemblances concern the vertical atmospheric structure. Although Titan is much colder, with a troposphere (˜94-˜70 K), a tropopause (70.4 K) and a stratosphere (˜70-175 K) its atmosphere presents a similar complex structure to that of the Earth. These analogies are linked to the presence in both atmospheres of greenhouse gases: CH4 and H2 on Titan, equivalent respectively to terrestrial condensable H2 O and non-condensable CO2 . In addition the haze particles and clouds in Titan's atmosphere play an antigreenhouse effect similar to that of the terrestrial atmospheric aerosols and clouds. Indeed, methane on Titan seems to play the role of water on the Earth, with a complex cycle, which still has to be understood. The possibility that Titan is covered with hydrocarbon oceans is now ruled out, but it is still possible that Titan's surface include lakes of methane and ethane. Moreover, the

Titan - a New Laboratory for Oceanography

NASA Astrophysics Data System (ADS)

Lorenz, R. D.

2001-12-01

Saturn's giant moon Titan has a thick (1.5 bar) nitrogen atmosphere, and quite probably large expanses of liquid hydrocarbons on its surface. The physical processes in these lakes and seas will open new vistas on oceanography and limnology. Although the Voyager-era paradigm of a deep, global ocean is ruled out by radar and infrared data showing that at least part of Titan's surface is icy, the photochemical arguments that originally led to the proposal of hydrocarbon oceans still apply. Even if the methane in the atmosphere is being resupplied by delivery from the interior, the ethane produced by photolysis would still accumulate to form large deposits on the surface. The near-infrared maps of Titan's surface from the Hubble Space Telescope and groundbased adaptive optics consistently show a number of dark (in fact, pitch-black!) regions that are strong candidates for hydrocarbon seas. These could be up to some 500km in extent. Titan promises to be a new laboratory for oceanography. Like in meteorology, many ocean processes are better parameterized than they are understood, and thus the different physical circumstances on Titan may shed new light on them. Titan has a lower gravity and its ocean fluids are of lower density, perhaps of lower viscosity (depending on solutes and suspended material) and probably rather more likely to cavitate. The ratio of atmospheric density to ocean density is much larger on Titan than on Earth, suggesting that liquid motions will be well-coupled to surface winds (although the distance from the sun is such that the energy in such winds is likely to be low.) Titan is also subject to strong tidal forces (the equilibrium tide due to Saturn's gravity is some 400x larger than that of the moon on Earth.) Although the 100m tidal bulge stays almost fixed because Titan rotates synchronously, the eccentricity of Titan's orbit leads to significant libration and variation in the tidal strength. The 500km seas allowed by the IR data may yet have a

Water vapor in Titan's atmosphere observed by Cassini/CIRS data

NASA Astrophysics Data System (ADS)

Cottini, V.; Nixon, C. A.; Jennings, D. E.; Teanby, N. A.; Anderson, C. M.; Irwin, P. G.; Flasar, F. M.

2011-12-01

Water vapor in Titan's atmosphere has only been detected by whole-disk observations from the Infrared Space Observatory [1]. In fact an earlier attempt to measure water vapor with NASA's Cassini Composite Infrared Spectrometer (CIRS, [2]) was unsuccessful, due to poor signal-to-noise in early versions of the calibration pipeline. In this paper we show the detection of the water vapor in Titan's atmosphere through the analysis of the emission lines present in the spectral range (60 - 300 cm-1) observed by the far-IR Focal Plane 1 (FP1) detector. We model high spectral resolution (0.5 cm-1) disk versus limb data to determine the water mixing ratio as a function of latitude and time (using data acquired from December 2004 to late 2011), also exploring differences between the leading and trailing side of Saturn's moon. The opacity sources in the atmospheric model include thermal emission from the moon, collision-induced absorption (CIA) from pairs of Titan's main atmospheric molecules, the stratospheric aerosol and emission lines from atmospheric gases across the FP1 spectral range (see Cottini et al., 2011 [3] for description of the model). The radiative transfer model and retrieval code (NEMESIS) is based on the method of optimal estimation to perform a correlated-k computation of synthetic spectra.Our determination of the atmospheric abundance of water vapor yields a value of ~0.14 ppb assuming a constant vertical profile, which corresponds to a column abundance of 4.3x1014 molecules/cm2. Preliminary results suggest a change in the atmospheric water vapour abundance during northern winter into early northern spring. We also detected water in CIRS high resolution limb spectra. Modeling these limb observations, mainly centered on two tangent heights, 125 and 225 km, allows us to constrain the water vapor abundance vertical profile; utilizing the limb data allows us to retrieve the water vapor from disk observations using a water vapor mixing ratio that varies in

Studies of the gas tori of Titan and Triton

NASA Technical Reports Server (NTRS)

Smyth, William H.

1995-01-01

Progress in the development of the model for the circumplanetary distribution of atomic hydrogen in the Saturn system produced by a Titan source is discussed. Because of the action of the solar radiation acceleration and the obliquity of Saturn, the hydrogen distribution is shown to undergo seasonal changes as the planet moves about the Sun. Preliminary model calculations show that for a continuous Titan source, the H distribution is highly asymmetric about the planet and has a density maximum near the dusk side of Saturn, qualitatively similar to the pattern recently deduced by Shemansky and Hall from observations acquired by the UVS instruments aboard the Voyager spacecrafts. The investigation of these Voyager data will be undertaken in the next project year.

Hot N2 in Titan's upper atmosphere

NASA Astrophysics Data System (ADS)

Lavvas, P.; Yelle, R. V.; Heays, A.; Campbell, L.; Brunger, M. J.; Galand, M.; Vuitton, V.

2015-10-01

We present a detailed model for the vibrational population of all non pre-dissociating excited electronic states of N2, as well as for the ground and ionic states,in Titan's atmosphere. Our model includes the detailed energy deposition calculations presented in the past [1] as well as the more recent developments in the high resolution N2 photo-absorption cross sections that allow us to calculate photo-excitation rates for different vibrational levels of singlet nitrogen states, and provide information for their pre-dissociation yields.In addition, we consider the effect of collisions and chemical reactions in the population of the different states. Our results demonstrate that a significant population of vibrationally excited ground state N2 survives in Titan's upper atmosphere. This hot N2population can improve the agreement between models and observations for the emission of the c'4 state that is significantly affected by resonant scattering. Moreover we discuss the potential implications of the vibrationally excited population on the ionospheric densities.

Renewable Energy Opportunities at the Kanto Installations, Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solana, Amy E.; Horner, Jacob A.; Russo, Bryan J.

2010-09-24

This document provides an overview of renewable resource development potential at the U.S. Army installations in the Kanto region in Japan, which includes Camp Zama, Yokohama North Dock, Sagamihara Family Housing Area (SFHA), Sagami General Depot, and Akasaka Press Center. This effort focuses on grid-connected generation of electricity from renewable energy sources and also on ground source heat pumps for heating and cooling buildings. The effort was funded by the Huntsville Army Corps of Engineers, and includes the development of a methodology for renewable resource assessment at Army installations located on foreign soil. The methodology is documented in Renewable Energymore » Assessment Methodology for Japanese OCONUS Army Installations. The site visit to the Kanto installations took place on April 5 and 6, 2010. At the current time, there are some renewable technologies that show economic potential. Because of siting restrictions and the small size of these installations, development of most renewable energy technologies will likely be limited to Camp Zama. Project feasibility is based on installation-specific resource availability and energy costs and projections based on accepted life-cycle cost methods. Development of any renewable energy project will be challenging, as it will require investigation into existing contractual obligations, new contracts that could be developed, the legality of certain partnerships, and available financing avenues, which involves the U.S. Forces Japan (USFJ), the Government of Japan (GOJ), and a number of other parties on both sides. The Army will not be able to implement a project without involvement and approval from the other services and multiple levels of Japanese government. However, implementation of renewable energy projects could be an attractive method for GOJ to reduce greenhouse gas emissions and lower annual utility payments to USFJ. This report recommends projects to pursue and offers approaches to use. The most

Japan Report.

DTIC Science & Technology

1987-02-03

of Keidanren’s U.S. Investment Mission, who is also vice chairman of the Industrial Bank of Japan; Mamoru Sakai, leader of the B Group of...Keidanren’s U.S. Investment Mission, who is also a director of the Japan Long-Term Credit Bank ; Masayoshi Tozaki, leader of the C Group of Keidanren’s U.S...Constitution. At the same time, Federal Reserve Bank Chairman Volcker has repeatedly stressed that maintaining the value of the dollar is essential. In

The greenhouse of Titan.

NASA Technical Reports Server (NTRS)

Sagan, C.

1973-01-01

Analysis of non-gray radiative equilibrium and gray convective equilibrium on Titan suggests that a massive molecular-hydrogen greenhouse effect may be responsible for the disagreement between the observed IR temperatures and the equilibrium temperature of an atmosphereless Titan. Calculations of convection indicate a probable minimum optical depth of 14 which corresponds to a molecular hydrogen shell of substantial thickness with total pressures of about 0.1 bar. It is suggested that there is an equilibrium between outgassing and blow-off on the one hand and accretion from the protons trapped in a hypothetical Saturnian magnetic field on the other, in the present atmosphere of Titan. It is believed that an outgassing equivalent to the volatilization of a few kilometers of subsurface ice is required to maintain the present blow-off rate without compensation for all geological time. The presence of an extensive hydrogen corona around Titan is postulated, with surface temperatures up to 200 K.

The Global Energy Balance of Titan

NASA Technical Reports Server (NTRS)

Li, Liming; Nixon, Conor A.; Achterberg, Richard K.; Smith, Mark A.; Gorius, Nicolas J. P.; Jiang, Xun; Conrath, Barney J.; Gierasch, Peter J.; Simon-Miller, Amy A.; Flasar, F. Michael;

Titan Temperature Lag Maps

NASA Image and Video Library

2016-02-18

This sequence of maps shows varying surface temperatures on Saturn moon Titan at two-year intervals, from 2004 to 2016. The measurements were made by the Composite Infrared Spectrometer CIRS instrument on NASA Cassini spacecraft. The maps show thermal infrared radiation (heat) coming from Titan's surface at a wavelength of 19 microns, a spectral window at which the moon's otherwise opaque atmosphere is mostly transparent. Temperatures have been averaged around the globe from east to west (longitudinally) to emphasize the seasonal variation across latitudes (from north to south). Black regions in the maps are areas for which there was no data. Titan's surface temperature changes slowly over the course of the Saturn system's long seasons, which each last seven and a half years. As on Earth, the amount of sunlight received at each latitude varies as the sun's illumination moves northward or southward over the course of the 30-year-long Saturnian year. When Cassini arrived at Saturn in 2004, Titan's southern hemisphere was in late summer and was therefore the warmest region. Shortly after the 2009 equinox, in 2010, temperatures were symmetrical across the northern and southern hemispheres, mimicking the distribution observed by Voyager 1 in 1980 (one Titan year earlier). Temperatures subsequently cooled in the south and rose in the north, as southern winter approached. While the overall trend in the temperature shift is clearly evident in these maps, there is narrow banding in several places that is an artifact of making the observations through Titan's atmosphere. The moon's dense, hazy envelope adds noise to the difficult measurement. Although it moves in latitude, the maximum measured temperature on Titan remains around -292 degrees Fahrenheit (-179.6 degrees Celsius, 93.6 Kelvin), with a minimum temperature at the winter pole only 6 degrees Fahrenheit (3.5 degrees Celsius or Kelvin) colder. This is a much smaller contrast than exists between Earth's warmest and

Shoreline features of Titan's Ontario Lacus from Cassini/VIMS observations

USGS Publications Warehouse

Barnes, J.W.; Brown, R.H.; Soderblom, J.M.; Soderblom, L.A.; Jaumann, R.; Jackson, B.; Le, Mouelic S.; Sotin, Christophe; Buratti, B.J.; Pitman, K.M.; Baines, K.H.; Clark, R.N.; Nicholson, P.D.; Turtle, E.P.; Perry, J.

2009-01-01

We analyze observations of Titan's south polar lake Ontario Lacus obtained by Cassini's Visual and Infrared Mapping Spectrometer during the 38th flyby of Titan (T38; 2007 December 5). These near-closest-approach observations have the highest signal-to-noise, the finest spatial resolution, and the least atmospheric influence of any near-infrared lake observation to date. We use the large, spatially flat, and low-albedo interior of Ontario Lacus as a calibration target allowing us to derive an analytical atmospheric correction for emission angle. The dark lake interior is surrounded by two separate annuli that follow the lake interior's contours. The inner annulus is uniformly dark, but not so much as the interior lake, and is generally 5-10 kilometers wide at the lake's southeastern margin. We propose that it represents wet lakebed sediments exposed by either tidal sloshing of the lake or seasonal methane loss leading to lower lake-volume. The exterior annulus is bright and shows a spectrum consistent with a relatively low water-ice content relative to the rest of Titan. It may represent fine-grained condensate deposits from a past era of higher lake level. Together, the annuli seem to indicate that the lake level for Ontario Lacus has changed over time. This hypothesis can be tested with observations scheduled for future Titan flybys. ?? 2008 Elsevier Inc.

Observations of Titan 3C-4 Transtage Fragmentation Debris

NASA Technical Reports Server (NTRS)

Cowardin, Heather; Seitzer, P.; Abercromby, K.; Barker, E.; Cardona, T.; Krisko, P.; Lederer, S.

2013-01-01

The fragmentation of a Titan 3C-4 Transtage (1968-081) on 21 February 1992 is one of only two known break-ups in or near geosynchronous orbit. The original rocket body and 24 pieces of debris are currently being tracked by the US Space Surveillance Network (SSN). The rocket body (SSN# 3432) and several of the original fragments (SSN# 25000, 25001, 30000, and 33511) were observed in survey mode during 2004-2010 using the 0.6-m Michigan Orbital DEbris Survey Telescope (MODEST) in Chile using a broad R filter. This paper will present a size distribution for all calibrated magnitude data acquired on MODEST. Size distribution plots will also be shown using historical models for small fragmentation debris (down to 10 cm) believed to be associated with the Titan break-up. In November 2010, visible broadband photometry (Johnson/Kron-Cousins BVRI) was acquired with the 0.9-m Small and Moderate Aperture Research Telescope System (SMARTS) at the Cerro Tololo Inter-American Observatory (CTIO) in Chile on several Titan fragments (SSN# 25001, 33509, 33510) and the parent rocket body. Color index data will be used to determine the fragment brightness distribution and how the data compares to spacecraft materials measured in the laboratory using similar photometric measurement techniques. In 2012, the SSN added 16 additional fragments to the catalogue. MODEST acquired magnitude data on ten Titan fragments in late 2012 and early 2013. The magnitude distribution of all the observed fragments are analyzed as a function of time. In order to better characterize the breakup fragments spectral measurements were acquired on the original rocket body and five Titan fragments using the 6.5-m Magellan telescopes at Las Campanas Observatory in Chile. The telescopic spectra are compared with laboratory acquired spectra of materials (e.g., Aluminum and various paints) and categorized based on known absorption features for spacecraft materials.

Titan's greenhouse and antigreenhouse effects

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

1992-01-01

Thermal mechanisms active in Titan's atmosphere are discussed in a brief review of data obtained during the Voyager I flyby in 1980. Particular attention is given to the greenhouse effect (GHE) produced by atmospheric H2, N2, and CH4; this GHE is stronger than that on earth, with CH4 and H2 playing roles similar to those of H2O and CO2 on earth. Also active on Titan is an antigreenhouse effect, in which dark-brown and orange organic aerosols block incoming solar light while allowing IR radiation from the Titan surface to escape. The combination of GHE and anti-GHE leads to a surface temperature about 12 C higher than it would be if Titan had no atmosphere.

Forecasting international tourism demand from the US, Japan and South Korea to Malaysia: A SARIMA approach

NASA Astrophysics Data System (ADS)

Borhan, Nurbaizura; Arsad, Zainudin

2014-07-01

One of the major contributing sectors for Malaysia's economic growth is tourism. The number of international tourist arrivals to Malaysia has been showing an upward trend as a result of several programs and promotion introduced by the Malaysian government to attract international tourists to the country. This study attempts to model and to forecast tourism demand for Malaysia by three selected countries: the US, Japan and South Korea. This study utilized monthly time series data for the period from January 1999 to December 2012 and employed the well-known Box-Jenkins seasonal ARIMA modeling procedures. Not surprisingly the results show the number of tourist arrivals from the three countries contain strong seasonal component as the arrivals strongly dependent on the season in the country of origin. The findings of the study also show that the number of tourist arrivals from the US and South Korea will continue to increase in the near future. Meanwhile the arrivals from Japan is forecasted to show a drop in the near future and as such tourism authorities in Malaysia need to enhance the promotional effort to attract more tourists from Japan to visit Malaysia.

Titan as the Abode of Life

PubMed Central

McKay, Christopher P.

2016-01-01

Titan is the only world we know, other than Earth, that has a liquid on its surface. It also has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan’s atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis, but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in its atmosphere. It is conceivable that H2O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures, azotosomes, in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic—polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the universe is full of diverse and wondrous life forms. PMID:26848689

Identification of Acetylene on Titan's Surface

NASA Astrophysics Data System (ADS)

Singh, S.; McCord, T. B.; Rodriguez, S.; Combe, J. P.; Cornet, T.; Le Mouelic, S.; Maltagliati, L.; Chevrier, V.; Clark, R. N.

2015-12-01

Titan's atmosphere is opaque in the near infrared due to gaseous absorptions, mainly by methane, and scattering by aerosols, except in a few "transparency windows" (e.g., Sotin et al., 2005). Thus, the composition of Titan surface remains difficult to access from space and is still poorly constrained, limited to ethane in the polar lakes (Brown et al., 2008) and a few possible organic molecules on the surface (Clark et al., 2010). Photochemical models suggest that most of the organic compounds formed in the atmosphere are heavy enough to condense and build up at the surface in liquid and solid states over geological timescale (Cordier et al., 2009, 2011). Acetylene (C2H2) is one of the most abundant organic molecules in the atmosphere and thus thought to present on the surface as well. Here we report direct evidence of solid C2H2 on Titan's surface using Cassini Visual and Infrared Mapping Spectrometer (VIMS) data. By comparing VIMS observations and laboratory measurements of solid and liquid C2H2, we identify a specific absorption at 1.55 µm that is widespread over Titan but is particularly strong in the brightest terrains. This surface variability suggests that C2H2 is mobilized by surface processes, such as surface weathering, topography, and dissolution/evaporation. The detection of C2H2 on the surface of Titan opens new paths to understand and constrain Titan's surface activity. Since C2H2 is highly soluble in Titan liquids (Singh et al. 2015), it can easily dissolve in methane/ethane and may play an important role in carving of fluvial channels and existence of karstic lakes at higher latitudes on Titan. These processes imply the existence of a dynamic surface with a continued history of erosion and deposition of C2H2 on Titan.

Handling Late Changes to Titan Science

NASA Technical Reports Server (NTRS)

Pitesky, Jo Eliza; Steadman, Kim; Ray, Trina; Burton, Marcia

2014-01-01

The Cassini mission has been in orbit for eight years, returning a wealth of scientific data from Titan and the Saturnian system. The mission, a cooperative undertaking between NASA, ESA and ASI, is currently in its second extension of the prime mission. The Cassini Solstice Mission (CSM) extends the mission's lifetime until Saturn's northern summer solstice in 2017. The Titan Orbital Science Team (TOST) has the task of integrating the science observations for all 56 targeted Titan flybys in the CSM. In order to balance Titan science across the entire set of flybys during the CSM, to optimize and influence the Titan flyby altitudes, and to decrease the future workload, TOST went through a "jumpstart" process before the start of the CSM. The "jumpstart" produced Master Timelines for each flyby, identifying prime science observations and allocating control of the spacecraft attitude to specific instrument teams. Three years after completing this long-range plan, TOST now faces a new challenge: incorporating changes into the Titan Science Plan without undoing the balance achieved during the jumpstart.

Equinoctial Activity Over Titan Dune Fields Revealed by Cassini/vims

NASA Astrophysics Data System (ADS)

Rodriguez, S.; Le Mouelic, S.; Barnes, J. W.; Hirtzig, M.; Rannou, P.; Sotin, C.; Brown, R. H.; Bow, J.; Vixie, G.; Cornet, T.; Bourgeois, O.; Narteau, C.; Courrech Du Pont, S.; Le Gall, A.; Reffet, E.; Griffith, C. A.; Jaumann, R.; Stephan, K.; Buratti, B. J.; Clark, R. N.; Baines, K. H.; Nicholson, P. D.; Coustenis, A.

2012-12-01

Titan, the largest satellite of Saturn, is the only satellite in the solar system with a dense atmosphere. The close and continuous observations of Titan by the Cassini spacecraft, in orbit around Saturn since July 2004, bring us evidences that Titan troposphere and low stratosphere experience an exotic, but complete meteorological cycle similar to the Earth hydrological cycle, with hydrocarbons evaporation, condensation in clouds, and rainfall. Cassini monitoring campaigns also demonstrate that Titan's cloud coverage and climate vary with latitude. Titan's tropics, with globally weak meteorological activity and widespread dune fields, seem to be slightly more arid than the poles, where extensive and numerous liquid reservoirs and sustained cloud activity have been discovered. Only a few tropo-spheric clouds have been observed at Titan's tropics during the southern summer. As equinox was approaching (in August 2009), they occurred more frequently and appeared to grow in strength and size. We present here the observation of intense brightening at Titan's tropics, very close to the equinox. These detections were conducted with the Visual and Infrared Mapping Spectrometer (VIMS) onboard Cassini. We will discuss the VIMS images of the three individual events detected so far, observed during the Titan's flybys T56 (22 May 2009), T65 (13 January 2010) and T70 (21 June 2010). T56, T65 and T70 observations show an intense and transient brighten-ing of large regions very close to the equator, right over the extensive dune fields of Senkyo, Belet and Shangri-La. They all appear spectrally and morphologically different from all transient surface features or atmospheric phenomena previously reported. Indeed, these events share in particular a strong brightening at wavelengths greater than 2 μm (especially at 5 μm), making them spectrally distinct from the small tropical clouds observed before the equinox and the large storms observed near the equator in September and October

Titan Orbiter with Aerorover Mission (TOAM)

NASA Astrophysics Data System (ADS)

Sittler, Edward C.; Cooper, J. F.; Mahaffey, P.; Esper, J.; Fairbrother, D.; Farley, R.; Pitman, J.; Kojiro, D. R.; TOAM Team

2006-12-01

We propose to develop a new mission to Titan called Titan Orbiter with Aerorover Mission (TOAM). This mission is motivated by the recent discoveries of Titan, its atmosphere and its surface by the Huygens Probe, and a combination of in situ, remote sensing and radar mapping measurements of Titan by the Cassini orbiter. Titan is a body for which Astrobiology (i.e., prebiotic chemistry) will be the primary science goal of any future missions to it. TOAM is planned to use an orbiter and balloon technology (i.e., aerorover). Aerobraking will be used to put payload into orbit around Titan. The Aerorover will probably use a hot air balloon concept using the waste heat from the MMRTG 500 watts. Orbiter support for the Aerorover is unique to our approach for Titan. Our strategy to use an orbiter is contrary to some studies using just a single probe with balloon. Autonomous operation and navigation of the Aerorover around Titan will be required, which will include descent near to the surface to collect surface samples for analysis (i.e., touch and go technique). The orbiter can provide both relay station and GPS roles for the Aerorover. The Aerorover will have all the instruments needed to sample Titan’s atmosphere, surface, possible methane lakes-rivers, use multi-spectral imagers for surface reconnaissance; to take close up surface images; take core samples and deploy seismometers during landing phase. Both active and passive broadband remote sensing techniques will be used for surface topography, winds and composition measurements.

Human Missions to Europa and Titan - Why Not?

NASA Astrophysics Data System (ADS)

Finarelli, Margaret G.

2004-04-01

of life in its subsurface oceans. The future remains unpredictable, as does the realization of any of these possibilities. However, projects such as this remind us that the final frontier for humans is truly outer space, and only our imagination will determine where the frontier stops. We can dream of visiting other planetary systems and perhaps even galaxies, but we must begin closer, and considering the scope of our known universe, Europa and Titan are very close indeed.

Human Missions to Europa and Titan - Why Not?

NASA Technical Reports Server (NTRS)

2004-01-01

of life in its subsurface oceans. The future remains unpredictable, as does the realization of any of these possibilities. However, projects such as this remind us that the final frontier for humans is truly outer space, and only our imagination will determine where the frontier stops. We can dream of visiting other planetary systems and perhaps even galaxies, but we must begin closer, and considering the scope of our known universe, Europa and Titan are very close indeed.

The bulk composition of Titan's atmosphere.

NASA Technical Reports Server (NTRS)

Trafton, L.

1972-01-01

Consideration of the physical constraints for Titan's atmosphere leads to a model which describes the bulk composition of the atmosphere in terms of observable parameters. Intermediate-resolution photometric scans of both Saturn and Titan, including scans of the Q branch of Titan's methane band, constrain these parameters in such a way that the model indicates the presence of another important atmospheric gas, namely, another bulk constituent or a significant thermal opacity. Further progress in determining the composition and state of Titan's atmosphere requires additional observations to eliminate present ambiguities. For this purpose, particular observational targets are suggested.

Support of US CLIVAR Project Office 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cummings, Donna

Director of JOSS, supervised the U.S. CLIVAR Project Office Director and helped direct the officer to enhance the goals and objectives of the U.S. CLIVAR Project and budget. Financial Manager of JOSS, worked to complete proposals and monitor compliance with award requirements and funding limitations and ensure the U.S. CLIVAR Project Office complied with UCAR policies and procedures. Project Coordinator administered the funding for the U.S. CLIVAR Project Office and was responsible for coordinating special projects that required additional support from JOSS technical staff. These projects included activities such as website updates, technology upgrades, production of printed reports, and developmentmore » of graphic elements like logos. Web Developer worked both on web development and graphic work and the work consisted of the following: Maintaining the site ? installing updates to Drupal CMS (Content Management System). Creating new templates for webpages and styling them with CSS and JavaScript/jQuery code. Fixing the styling on webpages that the content contributor/manager (Jenn Mays) created and has had trouble with. Creating new web forms for abstract uploading, subscriptions, and meeting registrations. Created 4 webpages for the ?ASP: Key Uncertainties in the Global Carbon-Cycle? meeting. Developed a document review form, instruction webpages, login redirect, dynamic table with form submissions for the US CLIVAR SSC Science Plan Document Review. This was open to the public from June 12, 2013 until July 10, 2013. During this time the user accounts had to be checked (daily) that were created by the public, to delete any spam ones. Graphics work: preparing images for general use on webpages, webpage banners, and for meeting name badges, creating a US CLIVAR letterhead, redesigning the US AMOC logo. System Administrator spent time working on the migration of the US CLIVAR site from the USGCRP office to UCAR here Boulder. This was done to increase the general

Titan's Ammonia Feature

NASA Technical Reports Server (NTRS)

Smythe, W.; Nelson, R.; Boryta, M.; Choukroun, M.

2011-01-01

NH3 has long been considered an important component in the formation and evolution of the outer planet satellites. NH3 is particularly important for Titan, since it may serve as the reservoir for atmospheric nitrogen. A brightening seen on Titan starting in 2004 may arise from a transient low-lying fog or surface coating of ammonia. The spectral shape suggests the ammonia is anhydrous, a molecule that hydrates quickly in the presence of water.

The environment of Titan, 1975

NASA Technical Reports Server (NTRS)

1976-01-01

Information regarding the physical characteristics of Titan and atmospheric models necessary to support design and mission planning of spacecraft that are to orbit Titan, enter its atmosphere or land on its surface is given.

Titan Extraterrestrial Land of Lakes

NASA Image and Video Library

2013-12-12

A colorized flyover of Titan's hydrocarbon seas and lakes. Data was collected by the Cassini spacecraft radar instrument between 2004 and 2013 during several flybys of Titan. Heights of features are exaggerated 10 times.

The Veils of Titan

NASA Image and Video Library

2004-05-06

The veils of Saturn's most mysterious moon have begun to lift in Cassini's eagerly awaited first glimpse of the surface of Titan, a world where scientists believe organic matter rains from hazy skies and seas of liquid hydrocarbons dot a frigid surface. Surface features previously observed only from Earth-based telescopes are now visible in images of Titan taken in mid-April by Cassini through one of the narrow angle camera's spectral filters specifically designed to penetrate the thick atmosphere. The image scale is 230 kilometers (143 miles) per pixel, and it rivals the best Earth-based images. The two images displayed here show Titan from a vantage point 17 degrees below its equator, yielding a view from 50 degrees north latitude all the way to its south pole. The image on the left was taken four days after the image on the right. Titan rotated 90 degrees in that time. The two images combined cover a region extending halfway around the moon. The observed brightness variations suggest a diverse surface, with variations in average reflectivity on scales of a couple hundred kilometers. The images were taken through a narrow filter centered at 938 nanometers, a spectral region in which the only obstacle to light is the carbon-based, organic haze. Despite the rather long 38-second exposure times, there is no noticeable smear due to spacecraft motion. The images have been magnified 10 times and enhanced in contrast to bring out details. No further processing to remove the effects of the overlying atmosphere has been performed. The superimposed grid over the images illustrates the orientation of Titan -- north is up and rotated 25 degrees to the left -- as well as the geographical regions of the satellite that are illuminated and visible. The yellow curve marks the position of the boundary between day and night on Titan. The enhanced image contrast makes the region within 20 degrees of this day and night division darker than usual. The Sun illuminates Titan from the

Seeing, touching and smelling the extraordinarily Earth-like world of Titan

NASA Astrophysics Data System (ADS)

2005-01-01

, these are rock-like solid at Titan's temperatures. Titan's soil appears to consist at least in part of precipitated deposits of the organic haze that shrouds the planet. This dark material settles out of the atmosphere. When washed off high elevations by methane rain, it concentrates at the bottom of the drainage channels and riverbeds contributing to the dark areas seen in DISR images. New, stunning evidence based on finding atmospheric argon 40 indicates that Titan has experienced volcanic activity generating not lava, as on Earth, but water ice and ammonia. Thus, while many of Earth's familiar geophysical processes occur on Titan, the chemistry involved is quite different. Instead of liquid water, Titan has liquid methane. Instead of silicate rocks, Titan has frozen water ice. Instead of dirt, Titan has hydrocarbon particles settling out of the atmosphere, and instead of lava, Titanian volcanoes spew very cold ice. Titan is an extraordinary world having Earth-like geophysical processes operating on exotic materials in very alien conditions. "We are really extremely excited about these results. The scientists have worked tirelessly for the whole week because the data they have received from Huygens are so thrilling. This is only the beginning, these data will live for many years to come and they will keep the scientists very very busy", said Jean-Pierre Lebreton, ESA's Huygens Project Scientist and Mission manager. The Cassini-Huygens mission is a cooperation between NASA, ESA and ASI, the Italian space agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, is managing the mission for NASA's Office of Space Science, Washington DC. JPL designed, developed and assembled the Cassini orbiter while ESA operated the Huygens atmospheric probe.

A survey aimed at general citizens of the US and Japan about their attitudes toward electronic medical data handling.

PubMed

Kimura, Michio; Nakaya, Jun; Watanabe, Hiroshi; Shimizu, Toshiro; Nakayasu, Kazuyuki

2014-04-25

To clarify the views of the general population of two countries (US and Japan), concerning the handling of their medical records electronically. We contacted people nationwide in the United States at random via Random Digit Dialing (RDD) to obtain 200 eligible responders. The questionnaire was for obtaining the information on their attitudes towards handling of their medical records, disclosure of the name of disease, secondary usage of information, compiling their records into a lifelong medical record, and access to their medical records on the Internet. We had also surveyed people of Shizuoka prefecture in Japan using same questionnaires sent by mail, for which we obtained 457 valid answers. Even in an unidentifiable manner, US people feel profit-oriented usage of medical data without specific consent is not acceptable. There is a significant difference between usage of unidentifiable medical data for profit (about 50% feel negatively) and for official/research purposes (about 30% feel negatively). About 60% of the US responders have a negative view on the proposal that unidentifiable medical information be utilized for profit by private companies to attain healthcare cost savings. As regards compiling a lifelong medical record, positive answers and negative answers are almost equally divided in the US (46% vs. 38%) while more positive attitudes are seen in Japan (74% vs. 12%). However, any incentive measures aimed at changing attitudes to such a compiling including the discount of healthcare costs or insurance fees are unwelcomed by people regardless of their age or health condition in both surveys. Regarding the access to their own medical record via the Internet, 38% of the US responders feel this is unacceptable while 50.5% were willing to accept it. Participants from the US think that the extent of the sharing their identifiable medical records should be limited to the doctors-in-charge and specified doctors referred to by their own doctors. On the other

Organic chemistry on Titan: Surface interactions

NASA Technical Reports Server (NTRS)

Thompson, W. Reid; Sagan, Carl

1992-01-01

The interaction of Titan's organic sediments with the surface (solubility in nonpolar fluids) is discussed. How Titan's sediments can be exposed to an aqueous medium for short, but perhaps significant, periods of time is also discussed. Interactions with hydrocarbons and with volcanic magmas are considered. The alteration of Titan's organic sediments over geologic time by the impacts of meteorites and comets is discussed.

AVIATR—Aerial Vehicle for In-situ and Airborne Titan Reconnaissance. A Titan airplane mission concept

NASA Astrophysics Data System (ADS)

Barnes, Jason W.; Lemke, Lawrence; Foch, Rick; McKay, Christopher P.; Beyer, Ross A.; Radebaugh, Jani; Atkinson, David H.; Lorenz, Ralph D.; Le Mouélic, Stéphane; Rodriguez, Sebastien; Gundlach, Jay; Giannini, Francesco; Bain, Sean; Flasar, F. Michael; Hurford, Terry; Anderson, Carrie M.; Merrison, Jon; Ádámkovics, Máté; Kattenhorn, Simon A.; Mitchell, Jonathan; Burr, Devon M.; Colaprete, Anthony; Schaller, Emily; Friedson, A. James; Edgett, Kenneth S.; Coradini, Angioletta; Adriani, Alberto; Sayanagi, Kunio M.; Malaska, Michael J.; Morabito, David; Reh, Kim

2012-03-01

We describe a mission concept for a stand-alone Titan airplane mission: Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR). With independent delivery and direct-to-Earth communications, AVIATR could contribute to Titan science either alone or as part of a sustained Titan Exploration Program. As a focused mission, AVIATR as we have envisioned it would concentrate on the science that an airplane can do best: exploration of Titan's global diversity. We focus on surface geology/hydrology and lower-atmospheric structure and dynamics. With a carefully chosen set of seven instruments—2 near-IR cameras, 1 near-IR spectrometer, a RADAR altimeter, an atmospheric structure suite, a haze sensor, and a raindrop detector—AVIATR could accomplish a significant subset of the scientific objectives of the aerial element of flagship studies. The AVIATR spacecraft stack is composed of a Space Vehicle (SV) for cruise, an Entry Vehicle (EV) for entry and descent, and the Air Vehicle (AV) to fly in Titan's atmosphere. Using an Earth-Jupiter gravity assist trajectory delivers the spacecraft to Titan in 7.5 years, after which the AVIATR AV would operate for a 1-Earth-year nominal mission. We propose a novel `gravity battery' climb-then-glide strategy to store energy for optimal use during telecommunications sessions. We would optimize our science by using the flexibility of the airplane platform, generating context data and stereo pairs by flying and banking the AV instead of using gimbaled cameras. AVIATR would climb up to 14 km altitude and descend down to 3.5 km altitude once per Earth day, allowing for repeated atmospheric structure and wind measurements all over the globe. An initial Team-X run at JPL priced the AVIATR mission at FY10 715M based on the rules stipulated in the recent Discovery announcement of opportunity. Hence we find that a standalone Titan airplane mission can achieve important science building on Cassini's discoveries and can likely do so

AVIATR - Aerial Vehicle for In-situ and Airborne Titan Reconnaissance A Titan Airplane Mission Concept

NASA Technical Reports Server (NTRS)

Barnes, Jason W.; Lemke, Lawrence; Foch, Rick; McKay, Christopher P.; Beyer, Ross A.; Radebaugh, Jani; Atkinson, David H.; Lorenz, Ralph D.; LeMouelic, Stephane; Rodriguez, Sebastien;

TSSM: The in situ exploration of Titan

NASA Astrophysics Data System (ADS)

Coustenis, A.; Lunine, J. I.; Lebreton, J. P.; Matson, D.; Reh, K.; Beauchamp, P.; Erd, C.

2008-09-01

The Titan Saturn System Mission (TSSM) mission was born when NASA and ESA decided to collaborate on two missions independently selected by each agency: the Titan and Enceladus mission (TandEM), and Titan Explorer, a 2007 Flagship study. TandEM, the Titan and Enceladus mission, was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call. The mission concept is to perform remote and in situ investigations of Titan primarily, but also of Enceladus and Saturn's magentosphere. The two satellites are tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TSSM will study Titan as a system, including its upper atmosphere, the interactions with the magnetosphere, the neutral atmosphere, surface, interior, origin and evolution, as well as the astrobiological potential of Titan. It is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini- Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time for Titan, several close flybys of Enceladus). One overarching goal of the TSSM mission is to explore in situ the atmosphere and surface of Titan. In the current mission architecture, TSSM consists of an orbiter (under NASA's responsibility) with a large host of instruments which would perform several Enceladus and Titan flybys before stabilizing in an orbit around Titan alone, therein delivering in situ elements (a Montgolfière, or hot air balloon, and a probe/lander). The latter are being studied by ESA. The balloon will circumnavigate Titan above the equator at an altitude of about 10 km for several months. The

Impact craters on Titan

USGS Publications Warehouse

Wood, Charles A.; Lorenz, Ralph; Kirk, Randy; Lopes, Rosaly; Mitchell, Karl; Stofan, Ellen; ,

2010-01-01

Five certain impact craters and 44 additional nearly certain and probable ones have been identified on the 22% of Titan's surface imaged by Cassini's high-resolution radar through December 2007. The certain craters have morphologies similar to impact craters on rocky planets, as well as two with radar bright, jagged rims. The less certain craters often appear to be eroded versions of the certain ones. Titan's craters are modified by a variety of processes including fluvial erosion, mass wasting, burial by dunes and submergence in seas, but there is no compelling evidence of isostatic adjustments as on other icy moons, nor draping by thick atmospheric deposits. The paucity of craters implies that Titan's surface is quite young, but the modeled age depends on which published crater production rate is assumed. Using the model of Artemieva and Lunine (2005) suggests that craters with diameters smaller than about 35 km are younger than 200 million years old, and larger craters are older. Craters are not distributed uniformly; Xanadu has a crater density 2-9 times greater than the rest of Titan, and the density on equatorial dune areas is much lower than average. There is a small excess of craters on the leading hemisphere, and craters are deficient in the north polar region compared to the rest of the world. The youthful age of Titan overall, and the various erosional states of its likely impact craters, demonstrate that dynamic processes have destroyed most of the early history of the moon, and that multiple processes continue to strongly modify its surface. The existence of 24 possible impact craters with diameters less than 20 km appears consistent with the Ivanov, Basilevsky and Neukum (1997) model of the effectiveness of Titan's atmosphere in destroying most but not all small projectiles.

Impact craters on Titan

USGS Publications Warehouse

Wood, C.A.; Lorenz, R.; Kirk, R.; Lopes, R.; Mitchell, Ken; Stofan, E.

2010-01-01

Five certain impact craters and 44 additional nearly certain and probable ones have been identified on the 22% of Titan's surface imaged by Cassini's high-resolution radar through December 2007. The certain craters have morphologies similar to impact craters on rocky planets, as well as two with radar bright, jagged rims. The less certain craters often appear to be eroded versions of the certain ones. Titan's craters are modified by a variety of processes including fluvial erosion, mass wasting, burial by dunes and submergence in seas, but there is no compelling evidence of isostatic adjustments as on other icy moons, nor draping by thick atmospheric deposits. The paucity of craters implies that Titan's surface is quite young, but the modeled age depends on which published crater production rate is assumed. Using the model of Artemieva and Lunine (2005) suggests that craters with diameters smaller than about 35 km are younger than 200 million years old, and larger craters are older. Craters are not distributed uniformly; Xanadu has a crater density 2-9 times greater than the rest of Titan, and the density on equatorial dune areas is much lower than average. There is a small excess of craters on the leading hemisphere, and craters are deficient in the north polar region compared to the rest of the world. The youthful age of Titan overall, and the various erosional states of its likely impact craters, demonstrate that dynamic processes have destroyed most of the early history of the moon, and that multiple processes continue to strongly modify its surface. The existence of 24 possible impact craters with diameters less than 20 km appears consistent with the Ivanov, Basilevsky and Neukum (1997) model of the effectiveness of Titan's atmosphere in destroying most but not all small projectiles. ?? 2009 Elsevier Inc.

Diurnal variations of Titan

NASA Astrophysics Data System (ADS)

Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

2009-04-01

We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

Cassini-Huygens makes first close approach to Titan

NASA Astrophysics Data System (ADS)

2004-10-01

environments ever attempted by a man-made object. On this pass, the Huygens touchdown site will be visible at around 167 degrees East and 10.7 degrees South on the sunlit face of Titan before reaching the point of closest approach. Data from the imaging and radar instrumentation on board Cassini-Huygens should provide a tantalising idea of what the surface of Titan could be like. A second view of the Huygens touchdown site will be possible on the second close fly-by in December. Jean-Pierre Lebreton, ESA’s Huygens Mission Manager and Project Scientist, said: “This first close-up look at Titan should enable us to find out just how precisely our atmospheric models fit with the real situation and of course we are excited about the prospect of discovering just what type of surface the Huygens probe could impact on early next year.” Today’s fly-by will also be looking at other aspects of Titan which, although it is the second largest moon in the Solar System after Jupiter’s Ganymede, we know relatively little about. The instruments on board the Cassini orbiter will be looking at the surface characteristics, atmospheric properties and interactions with Saturn’s magnetosphere. Huygens is dormant during the fly-by. The first images are expected at 03:30 CEST on 28 October. However, at the point of closest approach, Titan will have an apparent size far exceeding the field of view of the Cassini orbiter’s narrow-angle camera. Details below a 100-metre resolution may be seen if the camera can pierce the haze and fog. Spectacular multicolour images at 1-2 kilometre resolution are also anticipated from the Visual Infrared and Mapping Spectrometer and may reveal details about Titan surface structure and composition. However, the excitement does not stop after 26 October. On 28 October, at about 12:30 CEST, there is a close encounter with Tethys, another of the significant moons of Saturn. Tethys is a ball of solid ice about 1060 kilometres in diameter which orbits Saturn at a

Map of Titan - April 2011

NASA Image and Video Library

2011-10-26

This global digital map of Saturn moon Titan was created using images taken by NASA Cassini spacecraft imaging science subsystem ISS. Because of the scattering of light by Titan dense atmosphere, no topographic shading is visible here.

Space Art "Titan"

NASA Image and Video Library

2006-09-13

Artist Daniel Zeller used the breathtaking imagery from the Cassini spacecraft as a departure point to interpret the intricate surface of Saturn’s moon Titan in this peice titled "Titan". Cassini entered Saturn's orbit in July of 2004 after a seven-year voyage. It then began a four-year mission that includes more than 70 orbits around the ringed planet and its moons. Ink on Paper, 17x21. 2006. Copyrighted: For more information contact Curator, NASA Art Program.

Japan nurtures telecommunications on classic formula

NASA Astrophysics Data System (ADS)

Davis, Neil

1987-03-01

As in other industrial sectors, Japanese telecommunications organizations export significantly more products than they import, even when substantial cost-savings can be realized. One example is optical fibers, which some Japanese service companies do not buy from outside suppliers who have taken advantage of economies of scale. Nippon Telephone and Telegraph, until recently a common carrier, is meeting increasing competition from newly-formed indigenous telecommunications subsidiaries who are taking advantage of fiber optics and microwave communications capabilities. Various cooperative projects with U.S. companies are described, noting the tendency of Japanese manufacturers to cease relationships with U.S. companies when Japanese products become competitive and also the necessity of U.S. firms to gain political cooperation from the Japanese government in order to make sales in Japan.

Pickup Ion Signatures in the Vicinity of Titan

NASA Astrophysics Data System (ADS)

Regoli, L.; Coates, A. J.; Feyerabend, M.; Roussos, E.; Jones, G. H.; Krupp, N.; Thomsen, M. F.

2015-12-01

Being the only moon in the solar system with a significant atmosphere, Titan possesses an ionosphere that acts as a conducting obstacle to the incoming plasma from Saturn's magnetosphere. This creates a mass-loading of the magnetic field lines with freshly picked up ions from Titan's atmosphere on a process similar to that observed in comets (e.g. Coates et al. (1993), Journal of Geophysical Research, Vol. 98, No. A12, 20985-20994) and other moons like Jupiter's Io (e.g. Russell et al. (2003), Planetary and Space Science, Vol. 51, 233-238). However, while at other celestial bodies ion cyclotron waves arise as one of the main signatures of this process, this is not the case at Titan, with e.g. Cowee et al. (2010) (Journal of Geophysical Research, Vol. 115, A10224) attributing this to the local orientation of the magnetic field and the plasma flow preventing the waves to grow to levels detectable by the instruments on-board Cassini. For the reason above, the detection of pickup ions signatures needs to be approached through other methods. For this study, we analyze data from the CAPS/IMS instrument on-board Cassini. IMS is an ion mass spectrometer capable of detecting ion fluxes with energies from 1 eV to 50 keV with an atomic resolution of M/ΔM ~ 70. During many of the dedicated Titan flybys by Cassini, IMS was able to distinguish between ions of magnetospheric origin and of ionospheric origin, the latter being freshly picked up ions from Titan's ionosphere. With the help of ion spectrograms and time of flight (TOF) information, we carried out a survey of all the flybys for which IMS has data (the CAPS instrument was switched off after the 83th. dedicated flyby, named in the project as T83) in order to obtain information about the location and frequency of occurence for the signatures.

Titan Saturn System Mission Instrumentation

NASA Astrophysics Data System (ADS)

Coustenis, A.; Lunine, J.; Reh, K.; Lebreton, J.-P.; Erd, C.; Beauchamp, P.; Matson, D.

2012-10-01

The Titan Saturn System Mission (TSSM), another future mission proposed for Titan's exploration, includes an orbiter and two in situ elements: a hot-air balloon and a lake lander. The instrumentation of those two elements will be presented.

Amino acidis derived from Titan tholins

NASA Technical Reports Server (NTRS)

Khare, Bishun N.; Sagan, Carl; Ogino, Hiroshi; Nagy, Bartholomew; Er, Cevat

1986-01-01

The production of amino acids by acid treatment of Titan tholin is experimentally investigated. The synthesis of Titan tholin and the derivatization of amino acids to N-trifluoroacetyl isopropyl esters are described. The gas chromatography/mass spectroscopy analysis of the Titan tholins reveals the presence of glycine, alpha and beta alainine, and aspartic acid, and the total yield of amino acids is about 0.01.

JTEC panel on display technologies in Japan

NASA Technical Reports Server (NTRS)

Tannas, Lawrence E., Jr.; Glenn, William E.; Credelle, Thomas; Doane, J. William; Firester, Arthur H.; Thompson, Malcolm

1992-01-01

This report is one in a series of reports that describes research and development efforts in Japan in the area of display technologies. The following are included in this report: flat panel displays (technical findings, liquid crystal display development and production, large flat panel displays (FPD's), electroluminescent displays and plasma panels, infrastructure in Japan's FPD industry, market and projected sales, and new a-Si active matrix liquid crystal display (AMLCD) factory); materials for flat panel displays (liquid crystal materials, and light-emissive display materials); manufacturing and infrastructure of active matrix liquid crystal displays (manufacturing logistics and equipment); passive matrix liquid crystal displays (LCD basics, twisted nematics LCD's, supertwisted nematic LCD's, ferroelectric LCD's, and a comparison of passive matrix LCD technology); active matrix technology (basic active matrix technology, investment environment, amorphous silicon, polysilicon, and commercial products and prototypes); and projection displays (comparison of Japanese and U.S. display research, and technical evaluation of work).

Cassini Orbiter and Huygens Probe aboard the Titan IV

NASA Technical Reports Server (NTRS)

1997-01-01

At Launch Complex 40 on Cape Canaveral Air Station, the Mobile Service Tower has been retracted away from the Titan IVB/Centaur carrying the Cassini spacecraft, marking a major milestone in the launch countdown sequence. Retraction of the structure began about an hour later than scheduled due to minor problems with ground support equipment. The launch vehicle, Cassini spacecraft and attached Centaur stage encased in a payload fairing, altogether stand about 183 feet tall; mounted at the base of the launch vehicle are two upgraded solid rocket motors. Liftoff of Cassini on the journey to Saturn and its moon Titan is slated to occur during a window opening at 4:55 a.m. EDT, Oct. 13, and extending through 7:15 a.m.

The Jet Propulsion Laboratory manages the U.S. contribution to the Cassini mission for NASA's Office of Space Science.

Recent Origin of Titan's Orbital Eccentricity

NASA Astrophysics Data System (ADS)

Cuk, Matija

2014-05-01

Saturn's regular satellite system contains several dynamical mysteries, including the high tidal heating of Enceladus and undamped eccentricity of Titan. Lainey et al.(2012) proposed that the tidal evolution of the system is much faster than previously thought, which would explain heating of Enceladus and implies that some of the current satellites are less than 1 Gyr old. Cuk et al.(2014) pointed out that this fast tidal evolution could also explain the Titan-Hyperion resonance. If the inner, mid-sized Saturnian moons were re-accreted within the last Gyr, then the same event could have generated the observed eccentricity of Titan. Titan-Hyperion resonance puts strong constraints on this event, as many scenarios lead to the loss of Hyperion (usually through collision with Titan). Here I report on the ongoing study of the history of the Saturnian system, using symplectic integrators SIMPL (for stable configurations) and COMPLEX (for situations when the moons' orbits crossed). I find that the past system of icy satellites could have naturally evolved into instability, by having Dione and Rhea-like moons enter the mutual 4:3 resonance. This resonance is chaotic due to overlap with the solar evection resonance (i.e. the moons' precession rates in the mean-motion resonance overlap with Saturn's mean motion). The outcome of such resonance is a collision between the mid-sized moons, likely followed by re-accretion, with Titan being largely unaffected. I also find that close encounters between a mid-sized moon and Titan could with significant probability both excite Titan and preserve its resonance with Hyperion (cf. Hamilton 2013). I will present possible scenarios in which the previous system had an additional moon exterior to Rhea. This additional moon would have been destabilized by resonances with the inner moons and eventually absorbed by Titan, which acquired its eccentricity in the process. This research is supported by NASA's Outer Planet Research Program.

Mapping products of Titan's surface

USGS Publications Warehouse

Stephan, Katrin; Jaumann, Ralf; Karkoschka, Erich; Barnes, Jason W.; Tomasko, Martin G.; Turtle, Elizabeth P.; Le Corre, Lucille; Langhans, Mirjam; Le Mouelic, Stephane; Lorenz, Ralf D.; Perry, Jason; Brown, Robert H.; Lebreton, Jean-Pierre

2009-01-01

Remote sensing instruments aboard the Cassini spacecraft have been observed the surface of Titan globally in the infrared and radar wavelength ranges as well as locally by the Huygens instruments revealing a wealth of new morphological features indicating a geologically active surface. We present a summary of mapping products of Titan's surface derived from data of the remote sensing instruments onboard the Cassini spacecraft (ISS, VIMS, RADAR) as well as the Huygens probe (DISR) that were achieved during the nominal Cassini mission including an overview of Titan's recent nomenclature.

Dunes on Titan: A major landform revealing atmospheric and surface processes

NASA Astrophysics Data System (ADS)

Radebaugh, Jani; Lorenz, Ralph; Arnold, Karl; Savage, Christopher; Williams, Brigitte

The surface of Saturn’s moon Titan is covered in features that herald an active atmosphere and perhaps interior, such as dunes, rivers, lakes, mountain chains, and possible cryovolcanoes. Examining the geomorphology of these features helps us approach an understanding of the processes that are occurring or have occurred in the atmosphere and subsurface. A major landform on Titan is dunes, composed of organic sands ultimately derived from upper atmospheric processing of methane, subsequently perhaps eroded from organic sedimentary layers by methane rainfall and fluvial flow. Dunes fill vast fields, termed sand seas, similar to those observed in the Sahara, Namibia, and the Arabian peninsula. The equatorial region of Titan contains five separate sand seas as observed by the Cassini Synthetic Aperture Radar (SAR), Imaging Science Subsystem (ISS) and Visual and Infrared Mapping Spectrometer (VIMS) instruments. Together these sand seas cover 14 percent of the surface, totaling 12 million km2, and each have areas on the scale of the Saharan Great Sand Sea. They adjoin each other through sediment pathways around landmasses, and these large-scale connections as well as individual dune interactions with topography indicate a general transport of sediment from west to east. Measurements of dune height, width and spacing in Cassini SAR images reveal all of Titan’s thousands of linear dunes are of the same population. This indicates there was general uniformity in the wind and sediment supply conditions that led to the current dune forms. Variations in the parametric values result from deviations from these conditions, in some locations where elevated terrains have deflected winds. Dunes and sand seas are among the stratigraphically youngest features on Titan, showing little evidence of being affected by impact cratering or fluvial flow. However, individual dunes may be relatively stable, as the reorganization time scale for these features on Earth can be tens to hundreds

Titan's ground-based observations in the near-infrared.

NASA Astrophysics Data System (ADS)

Negrao, A.; Coustenis, A.; Hirtzig, M.; Lellouch, E.; Maillard, J.-P.; Rannou, P.; Gendron, E.; Drossart, P.; Combes, M.; Schmitt, B.

We have observed Titan from 1991 to 2005 between 0.8 and 2.5 microns with the Fourier Transform Spectrometer (FTS) at the Canada France Hawaii Telescope (CFHT) and the NACO adaptive optics system, at the ESO Very Large Telescope (VLT). The CFHT dataset allows us (by applying a microphysical and radiative transfer model) to explore five methane windows at 0.94, 1.08, 1.28, 1.58 and 2 microns at different longitudes and resolutions for a disk average. We will also present a selected sample of the spectra we acquired with VLT/NACO on January 16, 2005, in the K band between 2.03 and 2.40 micron (Negrão et al., 2006b). Our spectra, taken with adaptive optics, include the Huygens landing site and surrounding dark and bright areas. A comparative study of the methane absorption coefficients currently available from different sources was also performed demonstrating the great sensitivity of surface inferences to this model parameter. Based on our results, we recommend the methane absorption coefficients produced by Boudon et al. (2006) and Irwin et al. (2006) for future studies of Titan. The analysis of the data yields information on the atmosphere and surface properties. We find our data to be compatible with mixtures of water ice and tholin but have strong indication for the presence of an additional as yet unidentified component (or components) for which we offer a spectral description. The analysis of the VLT/NACO data seem to indicate a strong decrease of Titan's surface albedo between 2.03 and 2.12 microns in the Huygens landing site area. This is compatible with the presence of ices such as CH4 and H2 O at the surface. References: Negrão, A., et al. 2006a. Titan's surface albedo variations over a Titan season from near-infrared CFHT/FTS spectra Plan. Space Sci., in press; 1 Negrão, A., et al. 2006b. 2 micron spectroscopy of Huygens probe landing site on Titan with VLT/NACO. J. Geophys. Res. Planets, in press; Boudon, V., et al., 2006. The Vibrational Levels of

The Lakes and Seas of Titan

NASA Astrophysics Data System (ADS)

Hayes, Alexander G.

2016-06-01

Analogous to Earth's water cycle, Titan's methane-based hydrologic cycle supports standing bodies of liquid and drives processes that result in common morphologic features including dunes, channels, lakes, and seas. Like lakes on Earth and early Mars, Titan's lakes and seas preserve a record of its climate and surface evolution. Unlike on Earth, the volume of liquid exposed on Titan's surface is only a small fraction of the atmospheric reservoir. The volume and bulk composition of the seas can constrain the age and nature of atmospheric methane, as well as its interaction with surface reservoirs. Similarly, the morphology of lacustrine basins chronicles the history of the polar landscape over multiple temporal and spatial scales. The distribution of trace species, such as noble gases and higher-order hydrocarbons and nitriles, can address Titan's origin and the potential for both prebiotic and biotic processes. Accordingly, Titan's lakes and seas represent a compelling target for exploration.

Comparison of Current Regulatory Status for Gene-Based Vaccines in the U.S., Europe and Japan

PubMed Central

Nakayama, Yoshikazu; Aruga, Atsushi

2015-01-01

Gene-based vaccines as typified by plasmid DNA vaccines and recombinant viral-vectored vaccines are expected as promising solutions against infectious diseases for which no effective prophylactic vaccines exist such as HIV, dengue virus, Ebola virus and malaria, and for which more improved vaccines are needed such as tuberculosis and influenza virus. Although many preclinical and clinical trials have been conducted to date, no DNA vaccines or recombinant viral-vectored vaccines expressing heterologous antigens for human use have yet been licensed in the U.S., Europe or Japan. In this research, we describe the current regulatory context for gene-based prophylactic vaccines against infectious disease in the U.S., Europe, and Japan. We identify the important considerations, in particular, on the preclinical assessments that would allow these vaccines to proceed to clinical trials, and the differences on the regulatory pathway for the marketing authorization in each region. PMID:26344953

The rotation of Titan and Ganymede

NASA Astrophysics Data System (ADS)

Van Hoolst, Tim; Coyette, Alexis; Baland, Rose-Marie; Trinh, Antony

2016-10-01

The rotation rates of Titan and Ganymede, the largest satellites of Saturn and Jupiter, are on average equal to their orbital mean motion. Here we discuss small deviations from the average rotation for both satellites and evaluate the polar motion of Titan induced by its surface fluid layers. We examine different causes at various time scales and assess possible consequences and the potential of using librations and polar motion as probes of the interior structure of the satellites.The rotation rate of Titan and Ganymede cannot be constant on the orbital time scale as a result of the gravitational torque of the central planet acting on the satellites. Titan is moreover expected to show significant polar motion and additional variations in the rotation rate due to angular momentum exchange with the atmosphere, mainly at seasonal periods. Observational evidence for deviations from the synchronous state has been reported several times for Titan but is unfortunately inconclusive. The measurements of the rotation variations are based on determinations of the shift in position of Cassini radar images taken during different flybys. The ESA JUICE (JUpiter ICy moons Explorer) mission will measure the rotation variations of Ganymede during its orbital phase around the satellite starting in 2032.We report on different theoretical aspects of the librations and polar motion. We consider the influence of the rheology of the ice shell and take into account Cassini measurements of the external gravitational field and of the topography of Titan and similar Galileo data about Ganymede. We also evaluate the librations and polar motion induced by Titan's hydrocarbon seas and use the most recent results of Titan's atmosphere dynamics. We finally evaluate the potential of rotation variations to constrain the satellite's interior structure, in particular its ice shell and ocean.

Future Exploration of Titan and Enceladus

NASA Astrophysics Data System (ADS)

Matson, D. L.; Coustenis, A.; Lunine, J.; Lebreton, J.; Reh, K.; Beauchamp, P.

2009-05-01

The future exploration of Titan and Enceladus has become very important for the planetary community. The study conducted last year of the Titan Saturn System Mission (TSSM) led to an announcement in which ESA and NASA prioritized future OPF missions, stating that TSSM is planned after EJSM (for details see http://www.lpi.usra.edu/opag/). TSSM consists of a TSSM Orbiter that would carry two in situ elements: the Titan Montgolfiere hot air balloon and the Titan Lake Lander. The mission could launch in the 2023-2025 timeframe on a trajectory to arrive ~9 years later for a 4-year mission in the Saturn system. Soon after arrival at Saturn, the montgolfiere would be delivered to Titan to begin its mission of airborne, scientific observations of Titan from an altitude of about 10 km. The montgolfiere would have a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) power system and would be designed to last at least 6-12 months in Titan's atmosphere. With the predicted winds and weather, that would be sufficient to circumnavigate the globe! On a subsequent fly-by, the TSSM orbiter would release the Lake Lander on a trajectory toward Titan for a targeted entry. It would descend through the atmosphere making scientific measurements, much like Huygens did, and then land and float on one of Titan's seas. This would be its oceanographic phase, making a physical and chemical assessment of the sea. The Lake Lander would operate 8-10 hours until its batteries become depleted. Following the delivery of the in situ elements, the TSSM orbiter would explore the Saturn system via a 2-year tour that includes in situ sampling of Enceladus' plumes as well as Titan flybys. After the Saturn system tour, the TSSM orbiter would enter orbit around Titan for a global survey phase. Synergistic and coordinated observations would be carried out between the TSSM orbiter and the in situ elements. The scientific requirements were developed by the international TSSM Joint Science Definition

Rivers on Titan - numerical modelling of sedimentary structures

NASA Astrophysics Data System (ADS)

Misiura, Katarzyna; Czechowski, Leszek

2016-07-01

On Titan surface we can expect a few different geomorphological forms, e.g. fluvial valley and river channels. In our research we use numerical model of the river to determine the limits of different fluvial parameters that play important roles in evolution of the rivers on Titan and on Earth. We have found that transport of sediments as suspended load is the main way of transport for Titan [1]. We also determined the range of the river's parameters for which braided river is developed rather than meandering river. Similar, parallel simulations for rivers deltas are presented in [2]. Introduction Titan is a very special body in the Solar System. It is the only moon that has dense atmosphere and flowing liquid on its surface. The Cassini-Huygens mission has found on Titan meandering rivers, and indicated processes of erosion, transport of solid material and its sedimentation. This work is aimed to investigate the similarity and differences between these processes on Titan and the Earth. Numerical model The dynamical analysis of the considered rivers is performed using the package CCHE modified for the specific conditions on Titan. The package is based on the Navier-Stokes equations for depth-integrated two dimensional, turbulent flow and three dimensional convection-diffusion equation of sediment transport. For more information about equations see [1]. Parameters of the model We considered our model for a few different parameters of liquid and material transported by a river. For Titan we consider liquid corresponding to a Titan's rain (75% methane, 25% nitrogen), for Earth, of course, the water. Material transported in rivers on Titan is water ice, for Earth - quartz. Other parameters of our model are: inflow discharge, outflow level, grain size of sediments etc. For every calculation performed for Titan's river similar calculations are performed for terrestrial ones. Results and Conclusions The results of our simulation show the differences in behaviour of the

Clash of the Titans

ERIC Educational Resources Information Center

Subramaniam, Karthigeyan

2010-01-01

WebQuests and the 5E learning cycle are titans of the science classroom. These popular inquiry-based strategies are most often used as separate entities, but the author has discovered that using a combined WebQuest and 5E learning cycle format taps into the inherent power and potential of both strategies. In the lesson, "Clash of the Titans,"…

Overview of the BioBank Japan Project: Study design and profile.

PubMed

Nagai, Akiko; Hirata, Makoto; Kamatani, Yoichiro; Muto, Kaori; Matsuda, Koichi; Kiyohara, Yutaka; Ninomiya, Toshiharu; Tamakoshi, Akiko; Yamagata, Zentaro; Mushiroda, Taisei; Murakami, Yoshinori; Yuji, Koichiro; Furukawa, Yoichi; Zembutsu, Hitoshi; Tanaka, Toshihiro; Ohnishi, Yozo; Nakamura, Yusuke; Kubo, Michiaki

2017-03-01

The BioBank Japan (BBJ) Project was launched in 2003 with the aim of providing evidence for the implementation of personalized medicine by constructing a large, patient-based biobank (BBJ). This report describes the study design and profile of BBJ participants who were registered during the first 5-year period of the project. The BBJ is a registry of patients diagnosed with any of 47 target common diseases. Patients were enrolled at 12 cooperative medical institutes all over Japan from June 2003 to March 2008. Clinical information was collected annually via interviews and medical record reviews until 2013. We collected DNA from all participants at baseline and collected annual serum samples until 2013. In addition, we followed patients who reported a history of 32 of the 47 target diseases to collect survival data, including cause of death. During the 5-year period, 200,000 participants were registered in the study. The total number of cases was 291,274 at baseline. Baseline data for 199,982 participants (53.1% male) were available for analysis. The average age at entry was 62.7 years for men and 61.5 years for women. Follow-up surveys were performed for participants with any of 32 diseases, and survival time data for 141,612 participants were available for analysis. The BBJ Project has constructed the infrastructure for genomic research for various common diseases. This clinical information, coupled with genomic data, will provide important clues for the implementation of personalized medicine. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Seasonal multiphase equilibria in the atmospheres of Titan and Pluto

NASA Astrophysics Data System (ADS)

Tan, S. P.; Kargel, J. S.

2017-12-01

At the extremely low temperatures in Titan's upper troposphere and on Pluto's surface, the atmospheres as a whole are subject to freeze into solid solutions, not pure ices. The presence of the solid phases introduces conditions with rich phase equilibria upon seasonal changes, even if the temperature undergoes only small changes. For the first time, the profile of atmospheric methane in Titan's troposphere will be reproduced complete with the solid solutions. This means that the freezing point, i.e. the altitude where the first solid phase appears, is determined. The seasonal change will also be evaluated both at the equator and the northern polar region. For Pluto, also for the first time, the seasonal solid-vapor equilibria will be evaluated. The fate of the two solid phases, the methane-rich and carbon-monoxide-rich solid solutions, will be analyzed upon temperature and pressure changes. Such investigations are enabled by the development of a molecular-based thermodynamic model for cryogenic chemical systems, referred to as CRYOCHEM, which includes solid solutions in its phase-equilibria calculations. The atmospheres of Titan and Pluto are modeled as ternary gas mixtures: nitrogen-methane-ethane and nitrogen-methane-carbon monoxide, respectively. Calculations using CRYOCHEM can provide us with compositions not only in two-phase equilibria, but also that in three-phase equilibria. Densities of all phases involved will also be calculated. For Titan, density inversion between liquid and solid phases will be identified and presented. In the inversion, the density of solid phase is less than that in the liquid phase. The method and results of this work will be useful for further investigations and modeling on the atmospheres of Titan, Pluto, and other bodies with similar conditions in the Solar System and beyond.

Synthesis of nanosized sodium titanates

DOEpatents

Hobbs, David T.; Taylor-Pashow, Kathryn M. L.; Elvington, Mark C.

2015-09-29

Methods directed to the synthesis and peroxide-modification of nanosized monosodium titanate are described. Methods include combination of reactants at a low concentration to a solution including a nonionic surfactant. The nanosized monosodium titanate can exhibit high selectivity for sorbing various metallic ions.

Titan Topography: A Comparison Between Cassini Altimeter and SAR Imaging from Two Titan Flybys

NASA Astrophysics Data System (ADS)

Gim, Y.; Stiles, B.; Callahan, P. S.; Johnson, W. T.; Hensley, S.; Hamilton, G.; West, R.; Alberti, G.; Flamini, E.; Lorenz, R. D.; Zebker, H. A.; Cassini RADAR Team

2007-12-01

The Cassini RADAR has collected twelve altimeter data sets of Titan since the beginning of the Saturn Tour in 2004. Most of the altimeter measurements were made at high altitudes, from 4,000 km to 15,000 km, resulting in low spatial resolutions due to beam footprint sizes larger than 20 km, as well as short ground tracks less than 600 km. One flyby (T30) was dedicated to altimeter data collection from 15,000 km to the closest approach altitude of 950 km. This produced a beam footprint size of 6 km at the lowest altitude and an altimeter ground track of about 3,500 km covering Titan's surface from near the equator to high latitude areas near Titan's north pole. More importantly, the ground track is located inside the SAR swath viewed from an earlier Titan flyby (T28). This provides a rare opportunity to investigate Titan topography with a relatively high spatial resolution and compare nadir-looking altimeter data with side-looking SAR imaging. From altimeter data, we have measured the mean Titan radius of 2575.1 km +/- 0.1 km and observed rather complex topographical variations over a short distance. By comparing altimeter data and SAR images at altitudes below 2,000 km, we have found that there is a strong correlation between SAR brightness and altimeter waveform; SAR dark areas correspond to strong and sharp altimeter waveforms while SAR bright areas correspond to weak and diffused altimeter waveforms. The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

The U.S., Japan, and Asia: Challenges to U.S. Policy

DTIC Science & Technology

1993-10-01

1945-1990. Cambridge: Cambridge UP, 1992. (E 183.8 .J3 B78 1992) Burks , Ardath W. Japan: A Postindustrial Power. 3rd ed. Boulder: Westview, 1991. (DS 806...1988) Anchordoguy, Marie . Computers Inc.: Japan’s Challenge to IB4. Cambridge: Harvard UP, 1989. (HD 9696 .C63 J29 1989) Arrison, Thomas S., et. al...Strategv towards the East. London: International Institute for Strategic Studies, 1984. (U 162 .A23 no.192) Burke , Patrick, ed. Nuclear Weapons World

A FUSE Search for Argon on Titan

NASA Astrophysics Data System (ADS)

Gladstone, G. R.; Link, R.; Stern, S. A.; Festou, M.; Waite, J. H.

2002-09-01

The origin of Titan's thick nitrogen and methane atmosphere is a compelling enigma. One key and still missing observable concerns the abundances of noble gases in general, and argon in particular. Detection of sufficient argon could indicate that the N2 and CO now found in the atmosphere came in with ice during Titan's accretion. Alternatively, if there is very little argon, then we have to turn to models starting with frozen ammonia, methane and water ice, indicating a more important role for the Saturn sub-nebula, and requiring subsequent modification by photochemistry. Current estimates on the fraction of argon in Titan's atmosphere are crude, and based only on indirect evidence, and range up to 25%. On Sept. 21, 2000, using the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, we performed an observation of Titan to search for argon and to make a survey of Titan's dayglow in the 90--115 nm FUSE bandpass. No emissions were found in the 18 ks exposure, although only 7.4 ks were obtained when FUSE was in Earth's shadow where terrestrial airglow contamination is minimal. While no Ar, N, or N2 emissions were detected, 2-σ upper limits of 4 R (for Ar 104.8 nm) and 20 R (for N 113.4 nm) are found using the best of the FUSE data. There is a bump on the terrestrial geocorona H Lyβ emission at 102.5 nm which may be due to Titan and a Titan Torus. The signal in the bump is about 400 R. Model estimates suggest that the Lyβ brightness of Titan should be about 20 R and the Titan Torus in the 30--700 R range. For an assumed argon abundance of 5% the 104.8 nm emission is predicted to be 7 R, so the argon estimate is constraining already. The nitrogen estimate is very close to the model expectation of 15 R. An accurate determination of the abundance of argon on Titan would be useful in preparing for the arrival of the Cassini orbiter and Huygens probe at the Saturn system, so further FUSE observations of Titan are planned. We gratefully acknowledge support from NASA

Singular climatic activity at Equinox over Titan's dunefields as seen by CASSINI

NASA Astrophysics Data System (ADS)

Rodriguez, Sebastien; Le Mouélic, Stephane; Barnes, Jason W.; Charnay, Benjamin; Kok, Jasper F.; Lorenz, Ralph D.; Radebaugh, Jani; Cornet, Thomas; Bourgeois, Olivier; Lucas, Antoine; Rannou, Pascal; Griffith, Caitlin A.; Coustenis, Athena; Appéré, Thomas; Hirtzig, Mathieu; Sotin, Christophe; Soderblom, Jason M.; Brown, Robert H.; Bow, Jacob; Vixie, Graham

2016-04-01

Titan, the largest satellite of Saturn, is the only satellite in the solar system with a dense atmosphere. The close and continuous observations of Titan by the Cassini spacecraft, in orbit around Saturn since July 2004, bring us evidences that Titan troposphere and low stratosphere experience an exotic, but complete meteorological cycle similar to the Earth hydrological cycle, with hydrocarbons evaporation, condensation in clouds, and rainfall. Cassini monitoring campaigns also demonstrate that Titan's cloud coverage and climate vary with latitude. Titan's tropics, with globally weak meteorological activity and widespread dune fields, seem to be slightly more arid than the poles, where extensive and numerous liquid reservoirs and sustained cloud activity were discovered. Only a few tropo-spheric clouds have been observed at Titan's tropics during the southern summer [2-4]. As equinox was approaching (in August 2009), they occurred more frequently and appeared to grow in strength and size [5-7]. We present here the observation of intense brightening at Titan's tropics, very close to the equinox. These detec-tions were conducted with the Visual and Infrared Mapping Spectrometer [8] (VIMS) onboard Cassini. Figure 1 presents the VIMS color composite images of the three individual events detected so far, observed during the Titan's flybys T56 (22 May 2009), T65 (13 January 2010) and T70 (21 June 2010). T56, T65 and T70 observations show an intense and transient brightening of large regions very close to the equator, which all appear spectrally and morphologically different from all previous observed surface features or atmospheric phenomena. These events share in particular a strong brightening at wavelengths greater than 2 μm (especially at 5 μm), making them spectrally distinct from the few large storms observed near the equator. We will discuss the possibility that these singular events may have occurred very close to the surface, having a very local origin. We

The effects of upstream plasma properties on Titan's ionosphere

NASA Astrophysics Data System (ADS)

Ledvina, S. A.; Brecht, S. H.

2016-12-01

Cassini observations have found that the plasma and magnetic field conditions upstream of Titan are far more complex than they were thought to be after the Voyager encounter. Rymer et al., (2009) used the Cassini Plasma Spectrometer (CAPS) electron observations to classify the plasma conditions along Titan's orbit into 5 types (Plasma Sheet, Lobe, Mixed, Magnetosheath and Misc.). Nemeth et al., (2011) found that the CAPS ion observations could also be separated into the same plasma regions as defined by Rymer et al. Additionally the T-96 encounter found Titan in the solar wind adding a sixth classification. Understanding the effects of the variable upstream plasma conditions on Titan's plasma interaction and the evolution of Titan's ionosphere/atmosphere is one of the main objectives of the Cassini mission. To compliment the mission we perform hybrid simulations of Titan's plasma interaction to examine how the properties of the incident plasma (composition, density, temperature etc…) affect Titan's ionosphere. We examine how much ionospheric plasma is lost from Titan as well as the amount of mass and energy deposited into Titan's atmosphere.

Flyover of Sotra Facula, Titan

NASA Image and Video Library

2010-12-14

This frame from a movie is based on data from NASA Cassini spacecraft and shows a flyover of an area of Saturn moon Titan known as Sotra Facula. Scientists believe Sotra is the best case for an ice volcano, or cryovolcano, region on Titan.

Titan South Polar Cloud Burst

NASA Image and Video Library

2009-06-03

This infrared image of Saturn's moon Titan shows a large burst of clouds in the moon's south polar region. These clouds form and move much like those on Earth, but in a much slower, more lingering fashion, new results from NASA's Cassini Spacecraft show. This image is a color composite, with red shown at a 5-micron wavelength, green at 2.7 microns, and blue at 2 microns. An infrared color mosaic is also used as a background image (red at 5 microns, green at 2 microns, blue at 1.3 microns). The images were taken by Cassini's visual and infrared mapping spectrometer during a flyby of Titan on March 26, 2007, known as T27. For a similar view see PIA12004. Titan's southern hemisphere still shows a very active meteorology (the cloud appears in white-reddish tones) even in 2007. According to climate models, these clouds should have faded out since 2005. Scientists have monitored Titan's atmosphere for three-and-a-half years, between July 2004 and December 2007, and observed more than 200 clouds. The way these clouds are distributed around Titan matches scientists' global circulation models. The only exception is timing—clouds are still noticeable in the southern hemisphere while fall is approaching. http://photojournal.jpl.nasa.gov/catalog/PIA12005

Titan's Surface Temperatures Maps from Cassini - CIRS Observations

NASA Astrophysics Data System (ADS)

Cottini, Valeria; Nixon, C. A.; Jennings, D. E.; Anderson, C. M.; Samuelson, R. E.; Irwin, P. G. J.; Flasar, F. M.

2009-09-01

The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 μm (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the instrument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature profile by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). In future, application of our methodology over wide areas should greatly increase the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp. 1136-1150, 2008. Rodgers, C. D.: "Inverse Methods For Atmospheric Sounding: Theory and Practice". World Scientific, Singapore, 2000. Jennings, D.E., et al.: "Titan's Surface Brightness Temperatures." Ap. J. L., Vol. 691, pp. L103-L

Chemical investigation of Titan and Triton tholins

NASA Technical Reports Server (NTRS)

Mcdonald, Gene D.; Thompson, W. R.; Heinrich, Michael; Khare, Bishun N.; Sagan, Carl

1994-01-01

We report chromatographic and spectroscopic analyses of both Titan and Triton tholins, organic solids made from the plasma irradiation of 0.9:0.1 and 0.999:0.001 N2/CH4 gas mixtures, respectively. The lower CH4 mixing ratio leads to a nitrogen-richer tholin (N/C greater than 1), probably including nitrogen heterocyclic compounds. Unlike Titan tholin, bulk Triton tholin is poor in nitriles. From high-pressure liquid chromatography, ultraviolet and infrared spectroscopy, and molecular weight estimation by gel filtration chromatography, we conclude that (1) several H2O-soluble fractions, each with distinct UV and IR spectral signatures, are present, (2) these fractions are not identical in the two tholins, (3) the H2O-soluble fractions of Titan tholins do not contain significant amounts of nitriles, despite the major role of nitriles in bulk Titan tholin, and (4) the H2O-soluble fractions of both tholins are mainly molcules containing about 10 to 50 (C + N) atoms. We report yields of amino acids upon hydrolysis of Titan and Triton tholins. Titan tholin is largely insoluble in the putative hydrocarbon lakes or oceans on Titan, but can yield the H2O-soluble species investigated here upon contact with transient (e.g., impact-generated) liquid water.

Heavy Ion Formation in Titan's Ionosphere: Magnetospheric Introduction of Free Oxygen and Source of Titan's Aerosols?

NASA Technical Reports Server (NTRS)

Sittler, E. C., Jr.; Hartle, R. E.; Cooper, J. F.; Johnson, R. E.; Coates, A.; dePater, imke; Strom, Daphne; Simoes, F.; Steele, A.; Robb, F.

2007-01-01

With the recent discovery of heavy ions, positive and negative, by the Cassini Plasma Spectrometer (CAPS) instrument in Titan's ionosphere, it reveals new possibilities for aerosol formation at Titan and the introduction of free oxygen to the aerosol chemistry from Saturn's magnetosphere with Enceladus as the primary oxygen source. One can estimate whether the heavy ions in the ionosphere are of sufficient number to account for all the aerosols, under what conditions are favorable for heavy ion formation and how they are introduced as seed particles deeper in Titan's atmosphere where the aerosols form and eventually find themselves on Titan's surface where unknown chemical processes can take place. Finally, what are the possibilities with regard to their chemistry on the surface with some free oxygen present in their seed particles?

Size and shape of Saturn's moon Titan.

PubMed

Zebker, Howard A; Stiles, Bryan; Hensley, Scott; Lorenz, Ralph; Kirk, Randolph L; Lunine, Jonathan

2009-05-15

Cassini observations show that Saturn's moon Titan is slightly oblate. A fourth-order spherical harmonic expansion yields north polar, south polar, and mean equatorial radii of 2574.32 +/- 0.05 kilometers (km), 2574.36 +/- 0.03 km, and 2574.91 +/- 0.11 km, respectively; its mean radius is 2574.73 +/- 0.09 km. Titan's shape approximates a hydrostatic, synchronously rotating triaxial ellipsoid but is best fit by such a body orbiting closer to Saturn than Titan presently does. Titan's lack of high relief implies that most--but not all--of the surface features observed with the Cassini imaging subsystem and synthetic aperture radar are uncorrelated with topography and elevation. Titan's depressed polar radii suggest that a constant geopotential hydrocarbon table could explain the confinement of the hydrocarbon lakes to high latitudes.

Size and shape of Saturn's moon Titan

USGS Publications Warehouse

Zebker, Howard A.; Stiles, Bryan; Hensley, Scott; Lorenz, Ralph; Kirk, Randolph L.; Lunine, Jonathan

2009-01-01

Cassini observations show that Saturn's moon Titan is slightly oblate. A fourth-order spherical harmonic expansion yields north polar, south polar, and mean equatorial radii of 2574.32 ± 0.05 kilometers (km), 2574.36 ± 0.03 km, and 2574.91 ± 0.11 km, respectively; its mean radius is 2574.73 ± 0.09 km. Titan's shape approximates a hydrostatic, synchronously rotating triaxial ellipsoid but is best fit by such a body orbiting closer to Saturn than Titan presently does. Titan's lack of high relief implies that most—but not all—of the surface features observed with the Cassini imaging subsystem and synthetic aperture radar are uncorrelated with topography and elevation. Titan's depressed polar radii suggest that a constant geopotential hydrocarbon table could explain the confinement of the hydrocarbon lakes to high latitudes.

Industrial lasers in Japan

NASA Astrophysics Data System (ADS)

Karube, Norio

1991-03-01

I am to report on some aspects of industrial lasers in Japan. Mostly centering on the market. In Japan, the history of laser developnent is rather profound. And long. Ever since the first invention of the laser in this country in 1960. This is partly because of the fact that in Japan the spectroscopic studies of the ruby was very popular in the late 1950's. Ever since niost of the work has been done in the research laboratories of the industry, not in the universities or not in the governmental laboratories. And since that time our first activity was mainly centering on the basic research, but after that time we have the evolution of the technology. One of the features in Japan is that the activity of developement and research of laser technology from the very basic phase up to the present commercialization has been done by the same group of people, including ine. We had a national project which ended about six years ago which was sponsored by MITI. MITI is Ministry of International Trade and Industry in Japan. And because of this national project, the effect of this project had a very enlightening effect in Japan. And after that our Japanese laser market became very flourishing.

Titan Lingering Clouds

NASA Image and Video Library

2009-06-03

Lots of clouds are visible in this infrared image of Saturn's moon Titan. These clouds form and move much like those on Earth, but in a much slower, more lingering fashion, new results from NASA's Cassini spacecraft show. Scientists have monitored Titan's atmosphere for three-and-a-half years, between July 2004 and December 2007, and observed more than 200 clouds. The way these clouds are distributed around Titan matches scientists' global circulation models. The only exception is timing—clouds are still noticeable in the southern hemisphere while fall is approaching. Three false-color images make up this mosaic and show the clouds at 40 to 50 degrees mid-latitude. The images were taken by Cassini's visual and infrared mapping spectrometer during a close flyby of Titan on Sept. 7, 2006, known as T17. For a similar view see PIA12005. Each image is a color composite, with red shown at the 2-micron wavelength, green at 1.6 microns, and blue at 2.8 microns. An infrared color mosaic is also used as a background (red at 5 microns, green at 2 microns and blue at 1.3 microns). The characteristic elongated mid-latitude clouds, which are easily visible in bright bluish tones are still active even late into 2006-2007. According to climate models, these clouds should have faded out since 2005. http://photojournal.jpl.nasa.gov/catalog/PIA12004

ISO observations of Titan with SWS/grating

NASA Technical Reports Server (NTRS)

Coustenis, A.; Encrenaz, T.; Salama, A.; Lellouch, E.; Gautier, D.; Kessler, M. F.; deGraauw, T.; Samuelson, R. E.; Bjoraker, G.; Orton, G.

1997-01-01

The observations of Titan performed by the Infrared Space Observatory (ISO) short wavelength spectrometer (SWS), in the 2 micrometer to 45 micrometer region using the grating mode, are reported on. Special attention is given to data from Titan concerning 7 micrometer to 45 micrometer spectral resolution. Future work for improving Titan's spectra investigation is suggested.

Seasonal Changes in Titan's Meteorology

NASA Technical Reports Server (NTRS)

Turtle, E. P.; DelGenio, A. D.; Barbara, J. M.; Perry, J. E.; Schaller, E. L.; McEwen, A. S.; West, R. A.; Ray, T. L.

2011-01-01

The Cassini Imaging Science Subsystem has observed Titan for 1/4 Titan year, and we report here the first evidence of seasonal shifts in preferred locations of tropospheric methane clouds. South \\polar convective cloud activity, common in late southern summer, has become rare. North \\polar and northern mid \\latitude clouds appeared during the approach to the northern spring equinox in August 2009. Recent observations have shown extensive cloud systems at low latitudes. In contrast, southern mid \\latitude and subtropical clouds have appeared sporadically throughout the mission, exhibiting little seasonality to date. These differences in behavior suggest that Titan s clouds, and thus its general circulation, are influenced by both the rapid temperature response of a low \\thermal \\inertia surface and the much longer radiative timescale of Titan s cold thick troposphere. North \\polar clouds are often seen near lakes and seas, suggesting that local increases in methane concentration and/or lifting generated by surface roughness gradients may promote cloud formation. Citation

Prebiotic-like chemistry on Titan.

PubMed

Raulin, François; Brassé, Coralie; Poch, Olivier; Coll, Patrice

2012-08-21

Titan, the largest satellite of Saturn, is the only one in the solar system with a dense atmosphere. Mainly composed of dinitrogen with several % of methane, this atmosphere experiences complex organic processes, both in the gas and aerosol phases, which are of prebiotic interest and within an environment of astrobiological interest. This tutorial review presents the different approaches which can be followed to study such an exotic place and its chemistry: observation, theoretical modeling and experimental simulation. It describes the Cassini-Huygens mission, as an example of observational tools, and gives the new astrobiologically oriented vision of Titan which is now available by coupling the three approaches. This includes the many analogies between Titan and the Earth, in spite of the much lower temperature in the Saturn system, the complex organic chemistry in the atmosphere, from the gas to the aerosol phases, but also the potential organic chemistry on Titan's surface, and in its possible internal water ocean.

Impact Craters on Titan? Cassini RADAR View

NASA Technical Reports Server (NTRS)

Wood, Charles A.; Lopes, Rosaly; Stofan, Ellen R.; Paganelli, Flora; Elachi, Charles

2005-01-01

Titan is a planet-size (diameter of 5,150 km) satellite of Saturn that is currently being investigated by the Cassini spacecraft. Thus far only one flyby (Oct. 26, 2004; Ta) has occurred when radar images were obtained. In February, 2005, and approximately 20 more times in the next four years, additional radar swaths will be acquired. Each full swath images about 1% of Titan s surface at 13.78 GHz (Ku-band) with a maximum resolution of 400 m. The Ta radar pass [1] demonstrated that Titan has a solid surface with multiple types of landforms. However, there is no compelling detection of impact craters in this first radar swath. Dione, Tethys and other satellites of Saturn are intensely cratered, there is no way that Titan could have escaped a similar impact cratering past; thus there must be ongoing dynamic surface processes that erase impact craters (and other landforms) on Titan. The surface of Titan must be very young and the resurfacing rate must be significantly higher than the impact cratering rate.

Neonatal and Infant Mortality in Korea, Japan, and the U.S.: Effect of Birth Weight Distribution and Birth Weight-Specific Mortality Rates.

PubMed

Kim, Do Hyun; Jeon, Jihyun; Park, Chang Gi; Sriram, Sudhir; Lee, Kwang Sun

2016-09-01

Difference in crude neonatal and infant mortality rates (NMR and IMR) among different countries is due to the differences in its two determinants: birth weight distribution (BWD) and birth weight-specific mortality rates (BW-SMRs). We aimed to determine impact of BWD and BW-SMRs on differences in crude NMR and IMR among Korea, Japan, and the U.S. Our study used the live birth data of the period 2009 through 2010. Crude NMR/IMR are the lowest in Japan, 1.1/2.1, compared to 1.8/3.2, in Korea, and 4.1/6.2, in the U.S., respectively. Japanese had the best BW-SMRs of all birth weight groups compared to the Koreans and the U.S. The U.S. BWD was unfavorable with very low birth weight (< 1,500 g) rate of 1.4%, compared to 0.6% in Korea, and 0.8% in Japan. If Koreans and Japanese had the same BWD as in the U.S., their crude NMR/IMR would be 3.9/6.1 for the Koreans and 1.5/2.5 for the Japanese. If both Koreans and Japanese had the same BW-SMRs as in the U.S., the crude NMR/IMR would be 2.0/3.8 for the Koreans and 2.7/5.0 for the Japanese. In conclusion, compared to the U.S., lower crude NMR or IMR in Japan is mainly attributable to its better BW-SMRs. Koreans had lower crude NMR and IMR, primarily from its favorable BWD. Comparing crude NMR or IMR among different countries should include further exploration of its two determinants, BW-SMRs reflecting medical care, and BWD reflecting socio-demographic conditions.

Neonatal and Infant Mortality in Korea, Japan, and the U.S.: Effect of Birth Weight Distribution and Birth Weight-Specific Mortality Rates

PubMed Central

2016-01-01

Difference in crude neonatal and infant mortality rates (NMR and IMR) among different countries is due to the differences in its two determinants: birth weight distribution (BWD) and birth weight-specific mortality rates (BW-SMRs). We aimed to determine impact of BWD and BW-SMRs on differences in crude NMR and IMR among Korea, Japan, and the U.S. Our study used the live birth data of the period 2009 through 2010. Crude NMR/IMR are the lowest in Japan, 1.1/2.1, compared to 1.8/3.2, in Korea, and 4.1/6.2, in the U.S., respectively. Japanese had the best BW-SMRs of all birth weight groups compared to the Koreans and the U.S. The U.S. BWD was unfavorable with very low birth weight (< 1,500 g) rate of 1.4%, compared to 0.6% in Korea, and 0.8% in Japan. If Koreans and Japanese had the same BWD as in the U.S., their crude NMR/IMR would be 3.9/6.1 for the Koreans and 1.5/2.5 for the Japanese. If both Koreans and Japanese had the same BW-SMRs as in the U.S., the crude NMR/IMR would be 2.0/3.8 for the Koreans and 2.7/5.0 for the Japanese. In conclusion, compared to the U.S., lower crude NMR or IMR in Japan is mainly attributable to its better BW-SMRs. Koreans had lower crude NMR and IMR, primarily from its favorable BWD. Comparing crude NMR or IMR among different countries should include further exploration of its two determinants, BW-SMRs reflecting medical care, and BWD reflecting socio-demographic conditions. PMID:27510390

The tides of Titan.

PubMed

Iess, Luciano; Jacobson, Robert A; Ducci, Marco; Stevenson, David J; Lunine, Jonathan I; Armstrong, John W; Asmar, Sami W; Racioppa, Paolo; Rappaport, Nicole J; Tortora, Paolo

2012-07-27

We have detected in Cassini spacecraft data the signature of the periodic tidal stresses within Titan, driven by the eccentricity (e = 0.028) of its 16-day orbit around Saturn. Precise measurements of the acceleration of Cassini during six close flybys between 2006 and 2011 have revealed that Titan responds to the variable tidal field exerted by Saturn with periodic changes of its quadrupole gravity, at about 4% of the static value. Two independent determinations of the corresponding degree-2 Love number yield k(2) = 0.589 ± 0.150 and k(2) = 0.637 ± 0.224 (2σ). Such a large response to the tidal field requires that Titan's interior be deformable over time scales of the orbital period, in a way that is consistent with a global ocean at depth.

US/Brazil joint pilot project objectives

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-12-01

This paper describes a joint US/Brazil pilot project for rural electrification, whose major goals are: to establish technical, institutional, and economic confidence in using renewable energy (PV and wind) to meet the needs of the citizens of rural Brazil; to establish on-going institutional, individual and business relationships necessary to implement sustainable programs and commitments; to lay the groundwork for larger scale rural electrification through the use of distributed renewable technologies. The projects have supported low power home lighting systems, lighting and refrigeration for schools and medical centers, and water pumping systems. This is viewed as a long term project, wheremore » much of the equipment will come from the US, but Brazil will be responsible for program management, and sharing data gained from the program. The paper describes in detail the Brazilian program which was instituted to support this phased project.« less

Titan through Time: Evolution of Titan's Atmosphere and its Hydrocarbon Cycle on the Surface

NASA Astrophysics Data System (ADS)

Gilliam, Ashley E.

The Introduction and Appendix i-A outline briefly the history of Titan exploration since its discovery by Christiaan Huygens in 1675 through the recent International Mission of Cassini-Huygens.. Chapter 1: This chapter discusses two possible pathways of loss of the two main gases from Titan's post-accretional atmosphere, methane (CH 4) and ammonia (NH3), by the mechanisms of thermal escape and emission from the interior coupled with thermal escape. Chapter 2: In this chapter, a simple photolysis model is created, where the second most abundant component of the present-day Titan atmosphere, methane (CH4), can either escape the atmosphere or undergo photolytic conversion to ethane (C2H6). Chapter 3: This chapter examines different fluvial features on Titan, identified by the Cassini spacecraft, and evaluates the possibilities of channel formation by two mechanisms: dissolution of ice by a concentrated solution of ammonium sulfate, and by mechanical erosion by flow of liquid ammonia and liquid ethane. Chapter 4: This chapter presents: (1) new explicit mathematical solutions of mixed 1st and 2nd order chemical reactions, represented by ordinary differential first-degree and Riccati equations; (2) the computed present-day concentrations of the three gases in Titan's scale atmosphere, treated as at near-steady state; and (3) an analysis of the reported and computed atmospheric concentrations of CH4, CH 3, and C2H6 on Titan, based on the reaction rate parameters of the species, the rate parameters taken as constants representative of their mean values. Chapter 5: This chapter examines the possible reactions of methane formation in terms of the thermodynamic relationships of the reactions that include pure carbon as graphite, the gases H2, CO2, H2 O, and serpentinization and magnetite formation from olivine fayalite. (Abstract shortened by ProQuest.).

Titan LEAF: A Sky Rover Granting Targeted Access to Titan's Lakes and Plains

NASA Astrophysics Data System (ADS)

Ross, Floyd; Lee, Greg; Sokol, Daniel; Goldman, Benjamin; Bolisay, Linden

2016-10-01

Northrop Grumman, in collaboration with L'Garde Inc. and Global Aerospace Corporation (GAC), has been developing the Titan Lifting Entry Atmospheric Flight (T-LEAF) sky rover to roam the atmosphere and observe at close quarters the lakes and plains of Titan. T-LEAF also supports surface exploration and science by providing precision delivery of in situ instruments to the surface.T-LEAF is a maneuverable, buoyant air vehicle. Its aerodynamic shape provides its maneuverability, and its internal helium envelope reduces propulsion power requirements and also the risk of crashing. Because of these features, T-LEAF is not restricted to following prevailing wind patterns. This freedom of mobility allows it be commanded to follow the shorelines of Titan's methane lakes, for example, or to target very specific surface locations.T-LEAF utilizes a variable power propulsion system, from high power at ~200W to low power at ~50W. High power mode uses the propellers and control surfaces for additional mobility and maneuverability. It also allows the vehicle to hover over specific locations for long duration surface observations. Low power mode utilizes GAC's Titan Winged Aerobot (TWA) concept, currently being developed with NASA funding, which achieves guided flight without the use of propellers or control surfaces. Although slower than high powered flight, this mode grants increased power to science instruments while still maintaining control over direction of travel.Additionally, T-LEAF is its own entry vehicle, with its leading edges protected by flexible thermal protection system (f-TPS) materials already being tested by NASA's Hypersonic Inflatable Aerodynamic Decelerator (HIAD) group. This f-TPS technology allows T-LEAF to inflate in space, like HIAD, and then enter the atmosphere fully deployed. This approach accommodates entry velocities from as low as ~1.8 km/s if entering from Titan orbit, up to ~6 km/s if entering directly from Saturn orbit, like the Huygens probe

Diurnal variations of Titan's ionosphere

NASA Astrophysics Data System (ADS)

Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Müller-Wodarg, I. C. F.; Cravens, T. E.; Kasprzak, W. T.; Waite, J. H.

2009-06-01

We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ˜700 cm-3 below ˜1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.

Titan's surface-atmosphere system before and after Huygens

NASA Astrophysics Data System (ADS)

Lunine, Jonathan I.

2015-04-01

Speculation about the nature of Titan's surface-atmosphere interactions goes back to the discovery of methane in its atmosphere in 1943 but beginning in the early 1970's surface models began to grapple more quantitatively with the source of methane and its instability in the atmosphere. The role of molecular nitrogen in the atmosphere was first quantitatively considered at that time as well. The Voyager 1 flyby put a thick atmosphere of molecular nitrogen and methane on an observational footing, and made an atmospheric descent probe quite feasible. The measured high methane humidity made seas of methane and possibly other constituents an attractive possible source of methane and sink of its photolytic products, influencing the choice of instruments for a descent probe. At the time of Huygens' actual descent to the surface, global seas had been ruled out, and the Cassini Orbiter was just beginning to gather imaging and radar data of the surface. The fluvial nature of the Huygens landing site and presence of volatiles just below the surface were important discoveries of Huygens itself. Together with Cassini, Huygens painted a picture of a cryogenic desert with occasional violent methane rainstorms feeding streams that tumble pebbles of ice and organics downhill, the whole surrounded by dunes whose organic-rich particles are harvested from the chemical conversion of methane to more refractory compounds high in the atmosphere. And yet many mysteries remain. The large bodies of liquid methane are restricted to high latitudes. Most of the river valleys seen in Cassini radar data seem to run down to nowhere. And the ultimate source and replenishment of methane, although seemingly more strongly tied to the interior than before Cassini-Huygens, remain unresolved. Huygens gave us the only imaging of Titan's surface with a resolution good enough to follow fluvial processes all the way from the contextual geology, to channels, to the stream debris washed out into the plains

Titan's atmosphere and surface in 2026: the AVIATR Titan Airplane Mission

NASA Astrophysics Data System (ADS)

McKay, Chris; Barnes, Jason W.; Lemke, Lawrence; Beyer, Ross A.; Radebaugh, Jani; Atkinson, David; Flasar, F. Michael

2010-04-01

This poster describes the scientific, engineering, and operations planning for a Discovery / New Frontiers class Titan airplane mission, AVIATR (Aerial Vehicle for In-situ and Airborne Titan Reconnaissance). The mission would focus on Titan's surface and atmospheric diversity, using high-resolution imaging, near-infrared spectroscopy, a haze spectrometer, and atmospheric structure measurements. Previous mission studies have elected to use hot-air balloons to achieve similar science goals. These hot-air balloon concepts require the waste heat from inefficient thermocouple-based Radioisotope Thermoelectric Generators (RTGs) for buoyancy. New Advanced Stirling Radioisotope Generators (ASRGs) are much more efficient than RTGs both in terms of power produced per gram of plutonium-238 and the total watts-per-kilogram of the power unit itself. However, they are so efficient that they are much less effective for use in heating a hot-air balloon. Similarly, old-style RTGs produce insufficient specific power for heavier-than-air flight, but the use of 2 ASRGs can support a 120 kg airplane for a long-duration mission at Titan. The AVIATR airplane concept has several advantages in its science capabilities relative to a balloon, including the ability to target any site of interest, remaining on the dayside, stereo and repeat coverage, and easy altitude changes. It also possesses engineering advantages over a balloon like low total mass, a more straightforward deployment sequence, direct-to-Earth communications capability, and a more robust airframe.

Instrumentation for in situ sampling and analysis of compounds of interest to Astrobiology in the lower atmosphere and surface of Titan

NASA Technical Reports Server (NTRS)

Holland, Paul M.; Kojiro, Daniel R.; Stimac, Robert; Kaye, William; Takeuchi, Nori

2006-01-01

Instrumentation for exploration of the solar system will require new enabling technology for in situ sample acquisition and analysis of pre-biotic chemistry in extreme planetary environments, such as that encountered at the surface of Titan. The potential use of balloon aero-rovers for Titan places special emphasis on the importance of miniaturization, low power and low usage of consumables. To help meet this need, we are developing a miniature gas chromatograph coupled with a new Mini-Cell ion mobility spectrometer (GC-IMS), and one of us (PMH) has begun development work on a miniaturized cryogenic inlet system with sampling probes for Titan. This instrumentation, and its approach for meeting measurement needs for the analysis of prebiotic chemistry on Titan, will be discussed.

Titan and habitable planets around M-dwarfs.

PubMed

Lunine, Jonathan I

2010-01-01

The Cassini-Huygens mission discovered an active "hydrologic cycle" on Saturn's giant moon Titan, in which methane takes the place of water. Shrouded by a dense nitrogen-methane atmosphere, Titan's surface is blanketed in the equatorial regions by dunes composed of solid organics, sculpted by wind and fluvial erosion, and dotted at the poles with lakes and seas of liquid methane and ethane. The underlying crust is almost certainly water ice, possibly in the form of gas hydrates (clathrate hydrates) dominated by methane as the included species. The processes that work the surface of Titan resemble in their overall balance no other moon in the solar system; instead, they are most like that of the Earth. The presence of methane in place of water, however, means that in any particular planetary system, a body like Titan will always be outside the orbit of an Earth-type planet. Around M-dwarfs, planets with a Titan-like climate will sit at 1 AU--a far more stable environment than the approximately 0.1 AU where Earth-like planets sit. However, an observable Titan-like exoplanet might have to be much larger than Titan itself to be observable, increasing the ratio of heat contributed to the surface atmosphere system from internal (geologic) processes versus photons from the parent star.

Titan cells confer protection from phagocytosis in Cryptococcus neoformans infections.

PubMed

Okagaki, Laura H; Nielsen, Kirsten

2012-06-01

The human fungal pathogen Cryptococcus neoformans produces an enlarged "titan" cell morphology when exposed to the host pulmonary environment. Titan cells exhibit traits that promote survival in the host. Previous studies showed that titan cells are not phagocytosed and that increased titan cell production in the lungs results in reduced phagocytosis of cryptococcal cells by host immune cells. Here, the effect of titan cell production on host-pathogen interactions during early stages of pulmonary cryptococcosis was explored. The relationship between titan cell production and phagocytosis was found to be nonlinear; moderate increases in titan cell production resulted in profound decreases in phagocytosis, with significant differences occurring within the first 24 h of the infection. Not only were titan cells themselves protected from phagocytosis, but titan cell formation also conferred protection from phagocytosis to normal-size cryptococcal cells. Large particles introduced into the lungs were not phagocytosed, suggesting the large size of titan cells protects against phagocytosis. The presence of large particles was unable to protect smaller particles from phagocytosis, revealing that titan cell size alone is not sufficient to provide the observed cross-protection of normal-size cryptococcal cells. These data suggest that titan cells play a critical role in establishment of the pulmonary infection by promoting the survival of the entire population of cryptococcal cells.

Descriptive analysis and U.S. consumer acceptability of 6 green tea samples from China, Japan, and Korea.

PubMed

Lee, Jeehyun; Chambers, Delores H

2010-03-01

In the past, green tea has been one of the least popular nonalcoholic beverages for U.S. consumers. However, green tea has been receiving attention because of its potential health benefits. Knowing which green tea flavor attributes contribute to consumer liking will help the fast growing green tea business including green tea importers, tea shops, and beverage companies to understand which characteristics are most accepted by U.S. consumers. The objectives of this study were (1) to examine differences in acceptability of commonly available loose leaf and bagged green teas available from the major exporters to the U.S. (Japan, Korea, and China) and (2) to determine which green tea flavor characteristics are related to consumers' liking. In the study, consumers from the U.S. evaluated 6 green tea samples from China, Japan, and Korea for acceptability. A highly trained panel also evaluated the green tea samples to provide descriptive sensory attributes that might be related to acceptability. We found that U.S. consumers liked green tea samples with lower flavor intensity and lower bitterness intensity. Consumers' acceptability of green tea was negatively correlated with spinach and animalic flavor and bitterness and astringency of green teas evaluated using descriptive sensory analysis, but the correlation was only moderate. To learn what green tea flavor characteristics influence consumers' liking, future studies using more green tea samples with different flavor profiles are needed.

Titan's geoid and hydrology: implications for Titan's geological evolution

NASA Astrophysics Data System (ADS)

Sotin, Christophe; Seignovert, Benoit; Lawrence, Kenneth; MacKenzie, Shannon; Barnes, Jason; Brown, Robert

2014-05-01

A 1x1 degree altitude map of Titan is constructed from the degree 4 gravity potential [1] and Titan's shape [2] determined by the Radio Science measurements and RADAR observations of the Cassini mission. The amplitude of the latitudinal altitude variations is equal to 300 m compared to 600 m for the amplitude of the latitudinal shape variations. The two polar caps form marked depressions with an abrupt change in topography at exactly 60 degrees at both caps. Three models are envisaged to explain the low altitude of the polar caps: (i) thinner ice crust due to higher heat flux at the poles, (ii) fossil shape acquired if Titan had higher spin rate in the past, and (iii) subsidence of the crust following the formation of a denser layer of clathrates as ethane rain reacts with the H2O ice crust [3]. The later model is favored because of the strong correlation between the location of the cloud system during the winter season and the latitude of the abrupt change in altitude. Low altitude polar caps would be the place where liquids would run to and eventually form large seas. Indeed, the large seas of Titan are found at the deepest locations at the North Pole. However, the lakes and terrains considered to be evaporite candidates due to their spectral characteristics in the infrared [4,5] seem to be perched. Lakes may have been filled during Titan's winter and then slowly evaporated leaving material on the surface. Interestingly, the largest evaporite deposits are located at the equator in a deep depression 150 m below the altitude of the northern seas. This observation seems to rule out the presence of a global subsurface hydrocarbon reservoir unless the evaporation rate at the equator is faster than the transport of fluids from the North Pole to the equator. This work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. [1] Iess L. et al. (2012) Science, doi 10.1126/science.1219631. [2] Lorenz R.D. (2013

Planetary science: Titan's lost seas found

NASA Astrophysics Data System (ADS)

Sotin, Christophe

2007-01-01

When the Cassini spacecraft found no methane ocean swathing Saturn's moon Titan, it was a blow to proponents of an Earth-like world. The discovery of northern lakes on Titan gives them reason for cheer.

A Comparison of Telecollaborative Classes between Japan and Asian-Pacific Countries--Asian-Pacific Exchange Collaboration (APEC) Project

ERIC Educational Resources Information Center

Shimizu, Yoshihiko; Pack, Dwayne; Kano, Mikio; Okazaki, Hiroyuki; Yamamura, Hiroto

2016-01-01

The purpose of this report is to compare the effects of "telecollaborative classes" between students in Japan and those in Asian-Pacific countries such as Taiwan, Thailand, and the United States (Hawaii). The telecollaborative classes are part of the Asian-Pacific Exchange Collaboration (APEC) project, a 4-year project involving students…

Titan

NASA Technical Reports Server (NTRS)

Flasar, F. M.

1999-01-01

With a launch in December 2001, Space Infrared Telescope Facility (SIRTF) can observe Titan in the interval after Infrared Space Observatory (ISO) but before the onset of observations by Cassini. By virtue of its broad spectral coverage in the thermal infrared, 10-180 micron, its moderately high spectral resolution, approaching lambda/delta lambda=600 over part of this wavelength range, and the very high sensitivity of its helium- cooled detectors, the Infrared Spectrometer (IRS) and MIPS on SIRTF can address several issues raised through earlier observations by the Voyager IRIS experiment and by ISO. These include, for example, a better characterization of the vertical distribution of water in Titan's middle and upper atmospheres and the discovery of new compounds, such as allene or proprionitrile. This talk will address the temperature- and composition-sounding capabilities of SIRTF, particularly in the context of how they will complement Cassini observations and aid in their planning.

Science goals and mission concept for the future exploration of Titan and Enceladus

NASA Astrophysics Data System (ADS)

Tobie, G.; Teanby, N. A.; Coustenis, A.; Jaumann, R.; Raulin, F.; Schmidt, J.; Carrasco, N.; Coates, A. J.; Cordier, D.; De Kok, R.; Geppert, W. D.; Lebreton, J.-P.; Lefevre, A.; Livengood, T. A.; Mandt, K. E.; Mitri, G.; Nimmo, F.; Nixon, C. A.; Norman, L.; Pappalardo, R. T.; Postberg, F.; Rodriguez, S.; Schulze-Makuch, D.; Soderblom, J. M.; Solomonidou, A.; Stephan, K.; Stofan, E. R.; Turtle, E. P.; Wagner, R. J.; West, R. A.; Westlake, J. H.

2014-12-01

Saturn's moons, Titan and Enceladus, are two of the Solar System's most enigmatic bodies and are prime targets for future space exploration. Titan provides an analogue for many processes relevant to the Earth, more generally to outer Solar System bodies, and a growing host of newly discovered icy exoplanets. Processes represented include atmospheric dynamics, complex organic chemistry, meteorological cycles (with methane as a working fluid), astrobiology, surface liquids and lakes, geology, fluvial and aeolian erosion, and interactions with an external plasma environment. In addition, exploring Enceladus over multiple targeted flybys will give us a unique opportunity to further study the most active icy moon in our Solar System as revealed by Cassini and to analyse in situ its active plume with highly capable instrumentation addressing its complex chemistry and dynamics. Enceladus' plume likely represents the most accessible samples from an extra-terrestrial liquid water environment in the Solar system, which has far reaching implications for many areas of planetary and biological science. Titan with its massive atmosphere and Enceladus with its active plume are prime planetary objects in the Outer Solar System to perform in situ investigations. In the present paper, we describe the science goals and key measurements to be performed by a future exploration mission involving a Saturn-Titan orbiter and a Titan balloon, which was proposed to ESA in response to the call for definition of the science themes of the next Large-class mission in 2013. The mission scenario is built around three complementary science goals: (A) Titan as an Earth-like system; (B) Enceladus as an active cryovolcanic moon; and (C) Chemistry of Titan and Enceladus - clues for the origin of life. The proposed measurements would provide a step change in our understanding of planetary processes and evolution, with many orders of magnitude improvement in temporal, spatial, and chemical resolution

Interaction of Titan's ionosphere with Saturn's magnetosphere.

PubMed

Coates, Andrew J

2009-02-28

Titan is the only Moon in the Solar System with a significant permanent atmosphere. Within this nitrogen-methane atmosphere, an ionosphere forms. Titan has no significant magnetic dipole moment, and is usually located inside Saturn's magnetosphere. Atmospheric particles are ionized both by sunlight and by particles from Saturn's magnetosphere, mainly electrons, which reach the top of the atmosphere. So far, the Cassini spacecraft has made over 45 close flybys of Titan, allowing measurements in the ionosphere and the surrounding magnetosphere under different conditions. Here we review how Titan's ionosphere and Saturn's magnetosphere interact, using measurements from Cassini low-energy particle detectors. In particular, we discuss ionization processes and ionospheric photoelectrons, including their effect on ion escape from the ionosphere. We also discuss one of the unexpected discoveries in Titan's ionosphere, the existence of extremely heavy negative ions up to 10000amu at 950km altitude.

PEROXOTITANATE- AND MONOSODIUM METAL-TITANATE COMPOUNDS AS INHIBITORS OF BACTERIAL GROWTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hobbs, D.

2011-01-19

Sodium titanates are ion-exchange materials that effectively bind a variety of metal ions over a wide pH range. Sodium titanates alone have no known adverse biological effects but metal-exchanged titanates (or metal titanates) can deliver metal ions to mammalian cells to alter cell processes in vitro. In this work, we test a hypothesis that metal-titanate compounds inhibit bacterial growth; demonstration of this principle is one prerequisite to developing metal-based, titanate-delivered antibacterial agents. Focusing initially on oral diseases, we exposed five species of oral bacteria to titanates for 24 h, with or without loading of Au(III), Pd(II), Pt(II), and Pt(IV), andmore » measuring bacterial growth in planktonic assays through increases in optical density. In each experiment, bacterial growth was compared with control cultures of titanates or bacteria alone. We observed no suppression of bacterial growth by the sodium titanates alone, but significant (p < 0.05, two-sided t-tests) suppression was observed with metal-titanate compounds, particularly Au(III)-titanates, but with other metal titanates as well. Growth inhibition ranged from 15 to 100% depending on the metal ion and bacterial species involved. Furthermore, in specific cases, the titanates inhibited bacterial growth 5- to 375-fold versus metal ions alone, suggesting that titanates enhanced metal-bacteria interactions. This work supports further development of metal titanates as a novel class of antibacterials.« less

A whiff of nebular gas in Titan's atmosphere - Potential implications for the conditions and timing of Titan's formation

NASA Astrophysics Data System (ADS)

Glein, Christopher R.

2017-09-01

In situ data from the GCMS instrument on the Huygens probe indicate that Titan's atmosphere contains small amounts of the primordial noble gases 36Ar and 22Ne (tentative detection), but it is unknown how they were obtained by the satellite. Based on the apparent similarity in the 22Ne/36Ar (atom) ratio between Titan's atmosphere and the solar composition, a previously neglected hypothesis for the origin of primordial noble gases in Titan's atmosphere is suggested - these species may have been acquired near the end of Titan's formation, when the moon could have gravitationally captured some nebular gas that would have been present in its formation environment (the Saturnian subnebula). These noble gases may be remnants of a primary atmosphere. This could be considered the simplest hypothesis to explain the 22Ne/36Ar ratio observed at Titan. However, the 22Ne/36Ar ratio may not be exactly solar if these species can be fractionated by external photoevaporation in the solar nebula, atmospheric escape from Titan, or sequestration on the surface of Titan. While the GCMS data are consistent with a 22Ne/36Ar ratio of 0.05 to 2.5 times solar (1σ range), simple estimates that attempt to account for some of the effects of these evolutionary processes suggest a sub-solar ratio, which may be depleted by approximately one order of magnitude. Models based on capture of nebular gas can explain why the GCMS did not detect any other primordial noble gas isotopes, as their predicted abundances are below the detection limits (especially for 84Kr and 132Xe). It is also predicted that atmospheric Xe on Titan should be dominated by radiogenic 129Xe if the source of primordial Xe is nebular gas. Of order 10-2-10-1 bar of primordial H2 may have been captured along with the noble gases from a gas-starved disk, but this H2 would have quickly escaped from the initial atmosphere. To have the opportunity to capture nebular gas, Titan should have formed within ∼10 Myr of the formation of the

Coupled atmosphere-ocean models of Titan's past

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Pollack, James B.; Lunine, Jonathan I.; Courtin, Regis

1993-01-01

The behavior and possible past evolution of fully coupled atmosphere and ocean model of Titan are investigated. It is found that Titan's surface temperature was about 20 K cooler at 4 Gyr ago and will be about 5 K warmer 0.5 Gyr in the future. The change in solar luminosity and the conversion of oceanic CH4 to C2H6 drive the evolution of the ocean and atmosphere over time. Titan appears to have experienced a frozen epoch about 3 Gyr ago independent of whether an ocean is present or not. This finding may have important implications for understanding the inventory of Titan's volatile compounds.

Halving Titan

NASA Image and Video Library

2010-01-11

Titan seasonal hemispheric dichotomy is chronicled in black and white, with the moon northern half appearing slightly lighter than the dark southern half in this image taken by NASA Cassini spacecraft.

Laboratory simulation of photochemistry on Titan

NASA Astrophysics Data System (ADS)

Ferris, J.; Tran, B.; Force, M.; Briggs, R.; Vuitton, V.

Solar UV radiation is the principal energy source driving the chemistry in Titan's atmosphere ....(Sagan and Thompson, 1984). We have investigated the photochemical reactions in Titan's atmosphere in a flow reactor using the 185 and 254 nm UV emissions from a low-pressure mercury lamp ....(Clarke, et al., 2000) .....(Tran, et al., 2003). A solid product is formed using this apparatus and its optical properties have been measured since it is an analog of the haze layer on Titan. The complex refractive index of the solid material was determined and compared with the corresponding refractive index derived from the optical data obtained from Voyager 1 .......(Tran, et al., 2003). The current research focuses on the volatile reaction products. The principal gaseous compounds that absorb 185 nm light in Titan's atmosphere (acetylene, ethylene, and cyanoacetylene) were irradiated individually and in the presence of other atmospheric constituents at their mixing ratios in the Titan atmosphere. The objectives of this study are to determine the reaction pathways and to construct a model that reproduces the experimental results. Quantum yields for the loss of reactants and the formation of products were determined from the rates measured by gas chromatographic analysis. Irradiation of a mixture of acetylene, ethylene, cyanoacetylene, methane, hydrogen and nitrogen generated over 120 compounds. The structures of about 100 of these compounds were determined by GC/MS. The structures of many of these compounds were confirmed by use of authentic samples. The similarities and difference in the products obtained photochemically and by plasma discharges will be discussed. Clarke D. W., J. C. Joseph and J. P. Ferris, 2000, The design and use of a photochemical flow reactor: A laboratory study of the atmospheric chemistry of cyanoacetylene on Titan, Icarus, 282-291. Sagan C. and W. R. Thompson, 1984, Production and condensation of organic gases in the atmosphere of Titan, Icarus, 59

AERIAL MEASURING SYSTEM IN JAPAN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyons, Craig; Colton, David

2012-01-01

The U.S. Department of Energy National Nuclear Security Agency’s Aerial Measuring System deployed personnel and equipment to partner with the U.S. Air Force in Japan to conduct multiple aerial radiological surveys. These were the first and most comprehensive sources of actionable information for U.S. interests in Japan and provided early confirmation to the government of Japan as to the extent of the release from the Fukushima Daiichi Nuclear Power Generation Station. Many challenges were overcome quickly during the first 48 hours; including installation and operation of Aerial Measuring System equipment on multiple U.S. Air Force Japan aircraft, flying over difficultmore » terrain, and flying with talented pilots who were unfamiliar with the Aerial Measuring System flight patterns. These all combined to make for a dynamic and non-textbook situation. In addition, the data challenges of the multiple and on-going releases, and integration with the Japanese government to provide valid aerial radiological survey products that both military and civilian customers could use to make informed decisions, was extremely complicated. The Aerial Measuring System Fukushima response provided insight in addressing these challenges and gave way to an opportunity for the expansion of the Aerial Measuring System’s mission beyond the borders of the US.« less

Ridge of Jagged Peaks on Titan

NASA Image and Video Library

2016-07-29

This synthetic-aperture radar image was obtained by NASA's Cassini spacecraft during its T-120 pass over Titan's southern latitudes on June 7, 2016. The area shown here measures about 40 by 60 miles (70 by 100 kilometers) and is centered at about 60 degrees south latitude, 130 degrees west longitude. Radar illuminates the scene from the left at a 28-degree incidence angle. At the center of the image is a bright feature oriented from upper left to lower right. This is interpreted to be a long ridge with jagged peaks, likely created by methane rainfall erosion. Some of the individual peaks rise about 2,400 feet (800 meters) above the valley floor. The ridge has a considerably gentler slope on its left side (which appears brighter here) than on its right. Frequently, mountains shaped like this on Earth are fractured blocks of the planet's crust, thrusted upward and then tilted, creating a shallow slope on one side and a steeper slope on the fractured, faulted edge. Also presented here is an annotated version of the image, along with a radar image of the Dragoon Mountains in Arizona just east of Tucson. The Dragoon feature represents a tilted fault block, formed by spreading that has occurred across the western U.S., and has a similar shape to that of the Titan ridge. The Dragoon radar image was produced using data from NASA's Shuttle Radar Topography Mission (credit: NASA/JPL-Caltech/NGA). Radar illuminates the scene from the left in that image as well. Titan has displayed many features that are strikingly similar to Earth: lakes, seas, rivers, dunes and mountains. Scientists think it possible that, like Earth, the giant moon's crust has experienced familiar processes of uplift and spreading, followed by erosion. http://photojournal.jpl.nasa.gov/catalog/PIA20709

Poster 11: Simulating the VUV photochemistry in the upper atmosphere of Titan

NASA Astrophysics Data System (ADS)

Tigrine, Sarah; Carrasco, Nathalie; Vettier, Ludovic; Cernogora, Guy

2016-06-01

The Cassini mission around Titan revealed that the interaction between the N2 and CH4 molecules and the solar VUV radiation leads to a complex chemistry above an altitude of 800 km with the detection of heavy organic molecules like benzene (C6H6). This is consistent with an initiation of the aerosols in Titan's upper atmosphere. The presence of those molecules makes Titan a natural laboratory to witness and understand prebiotic-like chemistry but despite all the data collected, all the possible photochemical processes in such a hydrocarbon-nitrogen-rich environment are not precisely understood. This is why Titan's atmospheric chemistry experiments are of high interest, especially those focusing on the photochemistry as most of the Titan-like experiments are based on N2-CH4 plasma techniques. In order to reproduce this VUV photochemistry of N2 and CH4, we designed a photochemical reactor named APSIS which is to be coupled window-less with a VUV photon source as N2 needs wavelengths shorter than 100 nm in order to be dissociated. Those wavelengths are available at synchrotron beamlines but are challenging to obtain with common laboratory discharge lamps. At LATMOS, we developed a table-top VUV window-less source using noble gases for the micro-wave discharge. We started with Neon, as it has two resonance lines at 73.6 and 74.3 nm which allow us to dissociate and/or ionize both CH4 and N2. We will present here our first experimental results obtained with APSIS coupled with this VUV source and then discuss them regarding the Cassini data and other previous laboratory photochemical studies.

Titan Cells Confer Protection from Phagocytosis in Cryptococcus neoformans Infections

PubMed Central

Okagaki, Laura H.

2012-01-01

The human fungal pathogen Cryptococcus neoformans produces an enlarged “titan” cell morphology when exposed to the host pulmonary environment. Titan cells exhibit traits that promote survival in the host. Previous studies showed that titan cells are not phagocytosed and that increased titan cell production in the lungs results in reduced phagocytosis of cryptococcal cells by host immune cells. Here, the effect of titan cell production on host-pathogen interactions during early stages of pulmonary cryptococcosis was explored. The relationship between titan cell production and phagocytosis was found to be nonlinear; moderate increases in titan cell production resulted in profound decreases in phagocytosis, with significant differences occurring within the first 24 h of the infection. Not only were titan cells themselves protected from phagocytosis, but titan cell formation also conferred protection from phagocytosis to normal-size cryptococcal cells. Large particles introduced into the lungs were not phagocytosed, suggesting the large size of titan cells protects against phagocytosis. The presence of large particles was unable to protect smaller particles from phagocytosis, revealing that titan cell size alone is not sufficient to provide the observed cross-protection of normal-size cryptococcal cells. These data suggest that titan cells play a critical role in establishment of the pulmonary infection by promoting the survival of the entire population of cryptococcal cells. PMID:22544904

Dark Spots on Titan

NASA Image and Video Library

2005-05-02

This recent image of Titan reveals more complex patterns of bright and dark regions on the surface, including a small, dark, circular feature, completely surrounded by brighter material. During the two most recent flybys of Titan, on March 31 and April 16, 2005, Cassini captured a number of images of the hemisphere of Titan that faces Saturn. The image at the left is taken from a mosaic of images obtained in March 2005 (see PIA06222) and shows the location of the more recently acquired image at the right. The new image shows intriguing details in the bright and dark patterns near an 80-kilometer-wide (50-mile) crater seen first by Cassini's synthetic aperture radar experiment during a Titan flyby in February 2005 (see PIA07368) and subsequently seen by the imaging science subsystem cameras as a dark spot (center of the image at the left). Interestingly, a smaller, roughly 20-kilometer-wide (12-mile), dark and circular feature can be seen within an irregularly-shaped, brighter ring, and is similar to the larger dark spot associated with the radar crater. However, the imaging cameras see only brightness variations, and without topographic information, the identity of this feature as an impact crater cannot be conclusively determined from this image. The visual infrared mapping spectrometer, which is sensitive to longer wavelengths where Titan's atmospheric haze is less obscuring -- observed this area simultaneously with the imaging cameras, so those data, and perhaps future observations by Cassini's radar, may help to answer the question of this feature's origin. The new image at the right consists of five images that have been added together and enhanced to bring out surface detail and to reduce noise, although some camera artifacts remain. These images were taken with the Cassini spacecraft narrow-angle camera using a filter sensitive to wavelengths of infrared light centered at 938 nanometers -- considered to be the imaging science subsystem's best spectral filter

Experimental simulation of aerosols evolution in Titan's ionosphere

NASA Astrophysics Data System (ADS)

Chatain, A.; Carrasco, N.; Guaitella, O.

2017-09-01

Many recent studies on Titan are concerned with aerosols. In particular, questions are asked on how these complex organic molecules are formed and evolve in Titan's atmosphere. Here for the first time we experimentally study how harsh plasma environment simulating Titan ionosphere can affect these aerosols. Titan tholins are placed in a N2-H2 plasma reactor and sample signatures are measured by infrared transmission spectroscopy. First results show an evolution of the absorption bands. Therefore, plasma conditions seem to change tholin chemical structure.

NanoJapan: international research experience for undergraduates program: fostering U.S.-Japan research collaborations in terahertz science and technology of nanostructures

NASA Astrophysics Data System (ADS)

Phillips, Sarah R.; Matherly, Cheryl A.; Kono, Junichiro

2014-09-01

The international nature of science and engineering research demands that students have the skillsets necessary to collaborate internationally. However, limited options exist for science and engineering undergraduates who want to pursue research abroad. The NanoJapan International Research Experience for Undergraduates Program is an innovative response to this need. Developed to foster research and international engagement among young undergraduate students, it is funded by a National Science Foundation Partnerships for International Research and Education (PIRE) grant. Each summer, NanoJapan sends 12 U.S. students to Japan to conduct research internships with world leaders in terahertz (THz) spectroscopy, nanophotonics, and ultrafast optics. The students participate in cutting-edge research projects managed within the framework of the U.S-Japan NSF-PIRE collaboration. One of our focus topics is THz science and technology of nanosystems (or `TeraNano'), which investigates the physics and applications of THz dynamics of carriers and phonons in nanostructures and nanomaterials. In this article, we will introduce the program model, with specific emphasis on designing high-quality international student research experiences. We will specifically address the program curriculum that introduces students to THz research, Japanese language, and intercultural communications, in preparation for work in their labs. Ultimately, the program aims to increase the number of U.S. students who choose to pursue graduate study in this field, while cultivating a generation of globally aware engineers and scientists who are prepared for international research collaboration.

Probing Titan's atmosphere with a stellar occultation

NASA Technical Reports Server (NTRS)

Hubbard, W. B.

1991-01-01

The 3 July, 1989 occultation of 28 Sgr by Titan is discussed. The star was readily detectable throughout the occultation, reaching a minimum normalized flux of about 0.05. The occultation probed Titan's atmosphere in a region not studied by the Voyager spacecraft. The region is important for the aerobraking of Titan entry probes, and direct information about its properties is important for the Cassini mission. Occultation data (normalized stellar flux vs universal time) is shown in chart form for NASA supported stations, along with data from a collaborating group at the Wise observatory in Israel. Strong scintillation data of the star is noticeable in the data records, and provides information on waves/turbulence in Titan's high atmosphere.

A Numerical Study of Micrometeoroids Entering Titan's Atmosphere

NASA Technical Reports Server (NTRS)

Templeton, M.; Kress, M. E.

2011-01-01

A study using numerical integration techniques has been performed to analyze the temperature profiles of micrometeors entering the atmosphere of Saturn s moon Titan. Due to Titan's low gravity and dense atmosphere, arriving meteoroids experience a significant cushioning effect compared to those entering the Earth's atmosphere. Temperature profiles are presented as a function of time and altitude for a number of different meteoroid sizes and entry velocities, at an entry angle of 45. Titan's micrometeoroids require several minutes to reach peak heating (ranging from 200 to 1200 K), which occurs at an altitude of about 600 km. Gentle heating may allow for gradual evaporation of volatile components over a wide range of altitudes. Computer simulations have been performed using the Cassini/Huygens atmospheric data for Titan. Keywords micrometeoroid Titan atmosphere 1 Introduction On Earth, incoming micrometeoroids (100 m diameter) are slowed by collisions with air molecules in a relatively compact atmosphere, resulting in extremely rapid deceleration and a short heating pulse, often accompanied by brilliant meteor displays. On Titan, lower gravity leads to an atmospheric scale height that is much larger than on Earth. Thus, deceleration of meteors is less rapid and these particles undergo more gradual heating. This study uses techniques similar to those used for Earth meteoroid studies [1], exchanging Earth s planetary characteristics (e.g., mass and atmospheric profile) for those of Titan. Cassini/Huygens atmospheric data for Titan were obtained from the NASA Planetary Atmospheres Data Node [4]. The objectives of this study were 1) to model atmospheric heating of meteoroids for a range of micrometeor entry velocities for Titan, 2) to determine peak heating temperatures and rates for micrometeoroids entering Titan s atmosphere, and 3) to create a general simulation environment that can be extended to incorporate additional parameters and variables, including different

Clinical trial designs to obtain marketing authorization of drugs for haematological malignancy in Japan, the EU and the US.

PubMed

Nagai, Sumimasa; Ozawa, Keiya

2016-07-01

Differences in regulatory actions between Japan, the European Union (EU) and the United States (US) regarding the approval date and primary endpoints of pivotal trials have never been analysed comprehensively. This study aimed to examine such differences in haematological malignancy indications not only in applications for new molecular entity agents but also in supplemental applications for additional indications. A total of 101 haematological malignancy indications were examined for 58 drugs. Only 30 indications were approved by the regulatory agencies of all three regions with 25, 9 and 67 indications being first approved in Japan, the EU and the US, respectively. Regarding the 18 indications approved only in the US, 13 were approved based on results of single-arm trials. The approval of all nine indications approved first in the EU was based on results of comparative trials. The primary endpoints were different between the EU and the US in 4 of 49 indications approved by both regulatory agencies, all of which were approved earlier in the US than in the EU. This analysis shows that the US Food and Drug Administration has taken the most active attitude to acceptance of surrogate endpoints in single-arm trials. Therefore, not only shorter review time but also this attitude may lead to earlier approval in US. © 2016 John Wiley & Sons Ltd.

Simulating the VUV photochemistry of the upper atmosphere of Titan

NASA Astrophysics Data System (ADS)

Tigrine, Sarah; Carrasco, Nathalie; Vettier, Ludovic; Chitarra, Olivia; Cernogora, Guy

2016-10-01

The Cassini mission around Titan revealed that the interaction between the N2 and CH4 molecules and the solar VUV radiation leads to a complex chemistry above an altitude of 800km with the detection of heavy organic molecules like benzene (C6H6). This is consistent with an initiation of the aerosols in Titan's upper atmosphere. The presence of those molecules makes Titan a natural laboratory to witness and understand prebiotic-like chemistry but despite all the data collected, all the possible photochemical processes in such a hydrocarbon-nitrogen-rich environment are not precisely understood.This is why Titan's atmospheric chemistry experiments are of high interest, especially those focusing on the photochemistry as most of the Titan-like experiments are based on N2-CH4 plasma techniques. In order to reproduce this VUV photochemistry of N2 and CH4, we designed a photochemical reactor named APSIS which is to be coupled window-less with a VUV photon source as N2 needs wavelengths shorter than 100 nm in order to be dissociated. Those wavelengths are available at synchrotron beamlines but are challenging to obtain with common laboratory discharge lamps. At LATMOS, we developed a table-top VUV window-less source using noble gases for the micro-wave discharge. We started with Neon, as it has two resonance lines at 73.6 and 74.3 nm which allow us to dissociate and/or ionize both CH4 and N2.We will present here our first experimental results obtained with APSIS coupled with this VUV source. A range of different pressures below 1 mbar is tested, in parallel to different methane ratio. Moreover, other wavelengths are injected by adding some other noble gases in the MO discharge (He, Kr, Xe, Ar). We will review the mass spectra obtained in those different conditions and then discuss them regarding the Cassini data and other previous laboratory photochemical studies.

Potentially active regions on Titan: New processing of Cassini/VIMS data

NASA Astrophysics Data System (ADS)

Solomonidou, A.; Hirtzig, M.; Bratsolis, E.; Bampasidis, G.; Coustenis, A.; Kyriakopoulos, K.; Le Mouélic, S.; Stephan, K.; Jaumann, R.; Drossart, P.; Sotin, C.; St. Seymour, K.; Moussas, X.

2012-04-01

The Cassini Visual and Infrared Mapping Spectrometer (VIMS) obtained data of Titan's surface from flybys performed during the last seven years. In the 0.8-5.2 µm range, these spectro-imaging data showed that the surface consists of a multivariable geological terrain hosting complex geological processes. The data from the seven narrow methane spectral "windows" centered at 0.93, 1.08, 1.27, 1.59, 2.03, 2.8 and 5 µm provide some information on the lower atmospheric context and the surface parameters that we want to determine. Atmospheric scattering and absorption need to be clearly evaluated before we can extract the surface properties. We apply here a statistical method [1, 2] and a radiative transfer method [3, 1] on three potentially "active" regions on Titan, i.e. regions possibly subject to change over time (in brightness and/or in color etc) [4]: Tui Regio (20°S, 130°W) [5], a 1,500-km long flow-like figure, Hotei Regio (26°S, 78°W) [6], a 700-km wide volcanic-like terrain, and Sotra Facula (15°S, 42°W) [7], a 235-km in diameter area. With our method of Principal Component Analysis (PCA) we have managed to isolate specific regions of distinct and diverse chemical composition. We have tested this method on the previously studied Sinlap crater [8], delimitating compositional heterogeneous areas compatible with the published conclusions by Le Mouélic et al. (2008). Our follow-up method focuses on retrieving the surface albedo of the three areas and of the surrounding terrains with different spectral response by applying a radiative transfer (RT) code. We have used as input most of the Cassini HASI and DISR measurements, as well as new methane absorption coefficients [9], which are important to evaluate the atmospheric contribution and to allow us to better constrain the real surface alterations, by comparing the spectra of these regions. By superposing these results onto the PCA maps, we can correlate composition and morphology. As a test case, we used

Titan's methane clock

NASA Astrophysics Data System (ADS)

Nixon, C. A.; Jennings, D. E.; Romani, P. N.; Teanby, N. A.; Irwin, P. G. J.; Flasar, F. M.

2010-04-01

Measurements of the 12C/13C and D/H isotopic ratios in Titan's methane show intriguing differences from the values recorded in the giant planets. This implies that either (1) the atmosphere was differently endowed with material at the time of formation, or (2) evolutionary processes are at work in the moon's atmosphere - or some combination of the two. The Huygens Gas Chromatograph Mass Spectrometer Instrument (GCMS) found 12CH4/13CH4 = 82 +/- 1 (Niemann et al. 2005), some 7% lower than the giant planets' value of 88 +/- 7 (Sada et al. 1996), which closely matches the terrestrial inorganic standard of 89. The Cassini Composite Infrared Spectrometer (CIRS) has previously reported 12CH4/13CH4 of 77 +/-3 based on nadir sounding, which we now revise upwards to 80 +/- 4 based on more accurate limb sounding. The CIRS and GCMS results are therefore in agreement about an overall enrichment in 13CH4 of ~10%. The value of D/H in Titan's CH4 has long been controversial: historical measurements have ranged from about 8-15 x 10-5 (e.g. Coustenis et al. 1989, Coustenis et al. 2003). A recent measurement based on CIRS limb data by Bezard et al. (2007) puts the D/H in CH4 at (13 +/- 1) x 10-5, very much greater than in Jupiter and Saturn, ~2 x 10-5 (Mahaffy et al. 1998, Fletcher et al. 2009). To add complexity, the 12C/13C and D/H vary among molecules in Titan atmosphere, typically showing enhancement in D but depletion in 13C in the daughter species (H2, C2H2, C2H6), relative to the photochemical progenitor, methane. Jennings et al. (2009) have sought to interpret the variance in carbon isotopes as a Kinetic Isotope Effect (KIE), whilst an explanation for the D/H in all molecules remains elusive (Cordier et al. 2008). In this presentation we argue that evolution of isotopic ratios in Titan's methane over time forms a ticking 'clock', somewhat analogous to isotopic ratios in geochronology. Under plausible assumptions about the initial values and subsequent replenishment, various

[No relationship between blood type and personality: evidence from large-scale surveys in Japan and the US].

PubMed

Nawata, Kengo

2014-06-01

Despite the widespread popular belief in Japan about a relationship between personality and ABO blood type, this association has not been empirically substantiated. This study provides more robust evidence that there is no relationship between blood type and personality, through a secondary analysis of large-scale survey data. Recent data (after 2000) were collected using large-scale random sampling from over 10,000 people in total from both Japan and the US. Effect sizes were calculated. Japanese datasets from 2004 (N = 2,878-2,938), and 2,005 (N = 3,618-3,692) as well as one dataset from the US in 2004 (N = 3,037-3,092) were used. In all the datasets, 65 of 68 items yielded non-significant differences between blood groups. Effect sizes (eta2) were less than .003. This means that blood type explained less than 0.3% of the total variance in personality. These results show the non-relevance of blood type for personality.

Orographic Condensation at the South Pole of Titan

NASA Astrophysics Data System (ADS)

Corlies, Paul; Hayes, Alexander; Adamkovics, Mate

2016-10-01

Although many clouds have been observed on Titan over the past two decades (Griffith et al. 1998, Rodriquez et al 2009, Brown et al. 2010), only a handful of clouds have been analyzed in detail (Griffith et al 2005, Brown et al 2009, Adamkovics et al 2010). In light of new data and better radiative transfer (RT) modelling, we present here a reexamination of one of these cloud systems observed in March 2007, formerly identified as ground fog (Brown et al 2009), using the Cassini VIMS instrument. Combining our analysis with RADAR observations we attempt to understand the connection and correlation between this low altitude atmospheric phenomenon and the local topography, suggesting instead, a topographically driven (orographic) cloud formation mechanism. This analysis would present the first links between cloud formation and topography on Titan, and has valuable implications in understanding additional cloud formation mechanisms, allowing for a better understanding of Titan's atmospheric dynamics.We will also present an update on an ongoing ground based observation campaign looking for clouds on Titan. This campaign, begun back in April 2014, has been (nearly) continuously monitoring Titan for ongoing cloud activity. Although a variety of telescope and instruments have been used in an effort to best capture the onset of cloud activity expected at Titan's North Pole, no cloud outbursts have yet been observed from the ground (though frequent observations have been made with Cassini ISS/VIMS). This is interesting because it further suggests a developing dichotomy between Titan's seasons, since clouds were observable from the ground during southern summer. Thus, monitoring the onset of large scale cloud activity at Titan's North Pole will be crucial to understanding Titan's hydrologic cycle on seasonal timescales.

Nitrogen isotopic fractionation during plasma synthesis of Titan's aerosols analogues

NASA Astrophysics Data System (ADS)

Kuga, M.; Carrasco, N.; Marty, B.; Marrocchi, Y.; Bernard, S.; Rigaudier, T.

2013-12-01

initial gas mixture was analyzed by dual-inlet and tholins nitrogen isotopes were measured by EA-IRMS. PAMPRE tholins are depleted in 15N by -15 to -25‰ relative to the initial N2. Comparison of this nitrogen isotopic fractionation with a N2-CO-H2O plasma experiment done in very similar experimental conditions and resulting in a very close 15N depletion, has led us to interpret this 15N depletion between N2 and organic aerosols as a kinetic isotopic fractionation occurring during N2 dissociation in the plasma. This nitrogen isotopic fractionation, although important and larger than what is observed in natural terrestrial samples, is weak compared to what is measured in Titan's atmosphere for N2 and HCN. This apparent inconsistency will be discussed. [1] Niemann et al. (2010) JGR, 115, 1151-1154. [2] Vinatier et al. (2007) Icarus, 191, 712-721. [3] Liang et al. (2007) Ap.J. Lett., 664, L115. [4] Croteau et al. (2011) Ap.J. Lett., 728, L32. [5] Israel et al. (2005) [6] Lebonnois et al. (2002) Icarus, 159, 505-517. [7] Lavvas et al. 2008) Planet. Space Sci., 56, 67-99. [8] Szopa et al. (2006) Planet. Space. Sci., 54, 394-404. [9] Sciamma-O'Brien et al. (2010) Icarus, 209, 704-714.

NASA-ESA Joint Mission to Explore Two Worlds of Great Astrobiological Interest - Titan and Enceladus

NASA Astrophysics Data System (ADS)

Reh, K.; Coustenis, A.; Lunine, J.; Matson, D.; Lebreton, J.-P.; Erd, C.; Beauchamp, P.

2009-04-01

Rugged shorelines, laced with canyons, leading to ethane/methane seas glimpsed through an organic haze, vast fields of dunes shaped by alien sciroccos… An icy moon festooned with plumes of water-ice and organics, whose warm watery source might be glimpsed through surface cracks that glow in the infrared… The revelations by Cassini-Huygens about Saturn's crown jewels, Titan and Enceladus, have rocked the public with glimpses of new worlds unimagined a decade before. The time is at hand to capitalize on those discoveries with a broad mission of exploration that combines the widest range of planetary science disciplines—Geology, Geophysics, Atmospheres, Astrobiology,Chemistry, Magnetospheres—in a single NASA/ESA collaboration. The Titan Saturn System Mission will explore these exciting new environments, flying through Enceladus' plumes and plunging deep into Titan's atmosphere with instruments tuned to find what Cassini could only hint at. Exploring Titan with an international fleet of vehicles; from orbit, from the surface of a great polar sea, and from the air with the first hot air balloon to ride an extraterrestrial breeze, TSSM will turn our snapshot gaze of these worlds into an epic film. This paper will describe a collaborative NASA-ESA Titan Saturn System Mission that will open a new phase of planetary exploration by projecting robotic presence on the land, on the sea, and in the air of an active, organic-rich world.

Photochemical processes on Titan: Irradiation of mixtures of gases that simulate Titan's atmosphere

NASA Astrophysics Data System (ADS)

Tran, Buu N.; Joseph, Jeffrey C.; Force, Michael; Briggs, Robert G.; Vuitton, Veronique; Ferris, James P.

2005-09-01

Photochemical reaction pathways in Titan's atmosphere were investigated by irradiation of the individual components and the mixture containing nitrogen, methane, hydrogen, acetylene, ethylene, and cyanoacetylene. The quantum yields for the loss of the reactants and the formation of products were determined. Photolysis of ethylene yields mainly saturated compounds (ethane, propane, and butane) while photolysis of acetylene yields the same saturated compounds as well as ethylene and diacetylene. Irradiation of cyanoacetylene yields mainly hydrogen cyanide and small amounts of acetonitrile. When an amount of methane corresponding to its mixing ratio on Titan was added to these mixtures the quantum yields for the loss of reactants decreased and the quantum yields for hydrocarbon formation increased indicative of a hydrogen atom abstraction from methane by the photochemically generated radicals. GC/MS analysis of the products formed by irradiation of mixtures of all these gases generated over 120 compounds which were mainly aliphatic hydrocarbons containing double and triple bonds along with much smaller amounts of aromatic compounds like benzene, toluene and phenylacetylene. The reaction pathways were investigated by the use of 13C acetylene in these gas mixtures. No polycyclic aromatic compounds were detected. Vapor pressures of these compounds under conditions present in Titan's atmosphere were calculated. The low molecular weight compounds likely to be present in the atmosphere and aerosols of Titan as a result of photochemical processes are proposed.

Spacecraft Exploration of Titan and Enceladus

NASA Astrophysics Data System (ADS)

Matson, D.; Coustenis, A.; Lunine, J. I.; Lebreton, J.; Reh, K.; Beauchamp, P.; Erd, C.

2009-12-01

The future exploration of Titan and Enceladus is very important for planetary science. The study titled Titan Saturn System Mission (TSSM) led to an announcement in which ESA and NASA prioritized future OPF missions, stating that TSSM is planned after EJSM (for details see http://www.lpi.usra.edu/opag/). The TSSM concept consists of an Orbiter that would carry two in situ elements: the Titan Montgolfiere hot air balloon and the Titan Lake Lander. This mission could launch in the 2023-2025 timeframe on a trajectory to arrive ~9 years later and begin a 4-year mission in the Saturnian system. At an appropriate time after arrival at Saturn, the montgolfiere would be delivered to Titan to begin its mission of airborne, scientific observations of Titan from an altitude of about 10 km above the surface. The montgolfiere would have a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) power system whose waste heat would warm the gas in the balloon, providing buoyancy. It would be designed to survive at least 6-12 months in Titan’s atmosphere. With the predicted winds and weather, it should be possible to circumnavigate the globe! Later, on a subsequent fly-by, the TSSM orbiter would send the Lake Lander to Titan. It would descend through the atmosphere making scientific measurements, much like Huygens did, and then land and float on one of Titan’s seas. This would be its oceanographic phase of making a physical and chemical assessment of the sea. The Lake Lander would operate for 8-10 hours until its batteries become depleted. Following the delivery of the in situ elements, the TSSM orbiter would then explore the Saturn system for two years on a tour that includes in situ sampling of Enceladus’ plumes as well as flybys of Titan. After the Saturn tour, the TSSM orbiter would go into orbit around Titan and carry out a global survey phase. Synergistic observations would be carried out by the TSSM orbiter and the in situ elements. The scientific requirements for

Dragonfly: Investigating the Surface Composition of Titan

NASA Technical Reports Server (NTRS)

Brinckerhoff, W. B.; Lawrence, D. J.; Barnes, J. W.; Lorenz, R. D.; Horst, S. M.; Zacny, K.; Freissinet, C.; Parsons, A. M.; Turtle, E. P.; Trainer, M. G.;

Tohoku Earthquake-associated Marine Sciences: the research project for the Great East Japan Earthquake on March 11, 2011

NASA Astrophysics Data System (ADS)

Kitazato, Hiroshi; Kijima, Akihiro; Kogure, Kazuhiro; Hara, Motoyuki; Nagata, Toshi; Fujikura, Kasunori; Sonoda, Akira

2015-04-01

At 2:46 pm on March 11, 2011, a huge earthquake (M 9.0) occurred off the Pacific coast of Tohoku Region, Japan. The subsequent Tsunamis hit the coasts and seriously damaged fishing villages and towns in the area. Tohoku Region faces Northwestern Pacific where is one of the most productive oceans on the Earth. Then, what happened to the marine ecosystems in the Tohoku Region? What happened to the fishery bioresources? What is the mechanism to sustain high productivity in the Region? Is the ecosystem restoring after 4 years? What is required for the recovery of fisheries in the area? In order to answer these questions, the 10 years research project, TEAMS (Tohoku Ecosystem-Associated Marine Sciences) was launched in January 2012 funded by MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan) to conduct comprehensive research on the area. Tohoku University (TU), Atmosphere and Ocean Research Institute, the University of Tokyo (AORIUT), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), and 25 other institutions are conducting research for this project in close association with local government and fishery people. Currently, approximately 400 people (200 scientists, 160 students and others) covering physical, chemical, biological, and geological sciences including modeling take part in the project from all over Japan. MEXT also supports TEAMS by constructing R/V Shinsei Maru in 2013 for the oceanic investigations in the region. In this report, the overview of the ecosystem before and after the disaster, major findings and challenges of TEAMS will be described.

GCM Simulations of Titan's Paleoclimate

NASA Astrophysics Data System (ADS)

Lora, Juan M.; Lunine, Jonathan; Russell, Joellen; Hayes, Alexander

2014-11-01

The hemispheric asymmetry observed in the distribution of Titan's lakes and seas has been suggested to be the result of asymmetric seasonal forcing, where a relative moistening of the north occurs in the current epoch due to its longer and less intense summers. General circulation models (GCMs) of present-day Titan have also shown that the atmosphere transports methane away from the equator. In this work, we use a Titan GCM to investigate the effects that changes in Titan's effective orbital parameters have had on its climate in recent geologic history. The simulations show that the climate is relatively insensitive to changes in orbital parameters, with persistently dry low latitudes and wet polar regions. The amount of surface methane that builds up over either pole depends on the insolation distribution, confirming the influence of orbital forcing on the distribution of surface liquids. The evolution of the orbital forcing implies that the surface reservoir must be transported on timescales of ~30 kyr, in which case the asymmetry reverses with a period of ~125 kyr. Otherwise, the orbital forcing is insufficient for generating the observed dichotomy.

A Last Look at Titan

NASA Image and Video Library

2017-09-15

As it glanced around the Saturn system one final time, NASA's Cassini spacecraft captured this view of the planet's giant moon Titan. Interest in mysterious Titan was a major motivating factor to return to Saturn with Cassini-Huygens following the Voyager mission flybys of the early 1980s. Cassini and its Huygens probe, supplied by European Space Agency, revealed the moon to be every bit as fascinating as scientists had hoped. These views were obtained by Cassini's narrow-angle camera on Sept. 13, 2017. They are among the last images Cassini sent back to Earth. This natural color view, made from images taken using red, green and blue spectral filters, shows Titan much as Voyager saw it -- a mostly featureless golden orb, swathed in a dense atmospheric haze. An enhanced-color view (Figure 1) adds to this color a separate view taken using a spectral filter (centered at 938 nanometers) that can partially see through the haze. The views were acquired at a distance of 481,000 miles (774,000 kilometers) from Titan. The image scale is about 3 miles (5 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21890

U.S. Complicity and Japan's Wartime Medical Atrocities: Time for a Response.

PubMed

Devolder, Katrien

2015-01-01

Shortly before and during the Second World War, Japanese doctors and medical researchers conducted large-scale human experiments in occupied China that were at least as gruesome as those conducted by Nazi doctors. Japan never officially acknowledged the occurrence of the experiments, never tried any of the perpetrators, and never provided compensation to the victims or issued an apology. Building on work by Jing-Bao Nie, this article argues that the U.S. government is heavily complicit in this grave injustice, and should respond in an appropriate way in order to reduce this complicity, as well as to avoid complicity in future unethical medical experiments. It also calls on other U.S. institutions, in particular the Presidential Commission for the Study of Bioethical Issues, to urge the government to respond, or to at least inform the public and initiate a debate about this dark page of American and Japanese history.

US-Japan bumpy torus workshop. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-01-01

A US-Japan ELMO Bumpy Torus Workshop was held on November 1 and 2, 1985 in Encinitas, California. The workshop focused on recent results from the Nagoya Bumpy Torus, EBT-1/S, and the proposed EBS program. The major results presented at the Workshop included extensive theoretical analyses of diamagnetic well formation by hot-electron rings in SM-1, a comprehensive review of recent experiments in NBT, and divertor concepts for EBS. Ikegami and Fujiwara summarized work on ring- and core-plasma properties, including conditions for stable ring operation, measurements of ring beta and the scaling of stored energy with heating power. Fujiwara reported a numbermore » of exciting results on ambipolar potential control in NBT. The successful outcome of ICRF experiments using twelve antennas was particularly striking. In operating regimes characterized by positive ambipolar potentials, the plasma density reached values in excess of 10/sup 13/cm/sup -3/ with ion temperatures in the 200 to 400 eV range. The plasma potential decayed with a time constant approach 0.1 sec after the ICRF pulse ended. These results appeared to be similar to predictions made over the past several years of greatly improved particle confinement in the positive ambipolar potential state.« less

How Do High School Science Textbooks in Korea, Japan, and the U.S. Explain Bioaccumulation-Related Concepts?

ERIC Educational Resources Information Center

Kim, Heung-Tae; Kim, Jae Geun

2013-01-01

Although bioaccumulation-related concepts are important scientific knowledge, a study on whether high school textbooks include appropriate explanations has not been conducted. The present study investigated science and biology textbooks from Korea, Japan, and the U.S., focusing on how bioaccumulation-related concepts were defined, what types of…

Merging perspectives in the catchment sciences: the US-Japan Joint Seminar on catchment hydrology and forest biogeochemistry

Treesearch

Kevin J. McGuire; Stephen D. Sebestyen; Nobuhito Ohte; Emily M. Elliott; Takashi Gomi; Mark B. Green; Brian L. McGlynn; Naoko Tokuchi

2014-01-01

Japan has strong research programmes in the catchment sciences that overlap with interests in the US catchment science community, particularly in experimental and field-based research. Historically, however, there has been limited interaction between these two hydrologic science communities because of differences in language, culture, and research approaches. These...

Determination of the complex refractive indices of Titan haze analogs using photothermal deflection spectroscopy

NASA Astrophysics Data System (ADS)

Vuitton, Véronique; Tran, Buu N.; Persans, Peter D.; Ferris, James P.

2009-10-01

The spectrometers of the Cassini mission to the Saturn system have detected haze layers reaching up to 800 km in Titan's atmosphere. Knowledge of the complex refractive index ( k) of the haze is important for modeling the surface and atmosphere of Titan and retrieving some information about the functional groups present in the aerosols. Plasma discharges or ultraviolet radiation are commonly used to drive the formation of solid organics assumed to be good analogs of the Titan aerosols. [Tran, B.N., Ferris, J.P., Chera, J.J., 2003a. The photochemical formation of a Titan haze analog. Structural analysis by X-ray photoelectron and infrared spectroscopy. Icarus 162, 114-124; Tran, B.N., Force, M., Briggs, R., Ferris J.P., Persans, P., Chera, J.J., 2008. Photochemical processes on Titan: Irradiation of mixtures of gases that simulate Titan's atmosphere. Icarus 177, 106-115] reported the index of refraction of analogs synthesized by far ultraviolet irradiation of various gas mixtures. k was determined in the 200-800 nm wavelength range from transmission and reflection spectroscopy. However, this technique is limited by (i) uncertainties in the absorption values because of the small amounts of organics available, (ii) light scattering by the surface roughness and particulates in the sample. These limitations prompted us to perform new measurements using photothermal deflection spectroscopy (PDS), a technique based on the conversion of absorbed light into heat in the material of interest. By combining traditional spectroscopy ( λ < 500 nm) and PDS ( λ > 500 nm), we determined values of k over the 375-1550 nm range. k values as low as 10 -4 above 1000 nm were determined. This is one order of magnitude lower than the measurements generally used as a reference for Titan's aerosols analogs [Khare, B.N., Sagan, C., Arakawa, E.T., Suits, F., Callicott, T.A., Williams, M.W., 1984. Optical-constants of organic Tholins produced in a simulated Titanian atmosphere—from soft

The Geology of Titan as Revealed by Cassini

NASA Astrophysics Data System (ADS)

Lopes, Rosaly M.; Malaska, Michael; Solomonidou, Anezina; Cassini RADAR Team

2015-08-01

The Cassini-Huygens mission has revealed the surface of Titan in unprecedented detail, enabling us to discern the different geomorphic units on the surface and constrain the relative times of emplacement. We used a combined dataset of Cassini’s multiple instruments and instrument modes: Synthetic Aperture Radar (SAR-RADAR), altimetry, scatterometry, imaging (ISS) and hyperspectral imaging (VIMS) to provide information on Titan’s surface geology. Continuing the initial work described in Lopes et al. [1], we established the major geomorphologic unit classes on Titan using data from flybys Ta through T92 (October 2004-July 2013). We will present the global distribution of the major classes of units and, where there are direct morphological contacts, describe how these classes of units relate to each other in terms of setting and emplacement history. The classes of units are mountainous/hummocky terrains, plains, dunes, labyrinthic terrains and lakes. The oldest classes of units are the mountainous/hummocky and the labyrinthic terrains. The mountainous/hummocky terrains consist of mountain chains and isolated radar-bright terrains. The labyrinthic terrains consist of highly incised dissected plateaus with medium radar backscatter. The plains are younger than both mountainous/hummocky and labyrinthic unit classes. Dunes and lakes are the youngest unit classes on Titan; no contact is observed between them but it is likely that both processes are still active. We have identified individual features such as craters, channels, and candidate cryovolcanic features. Characterization and comparison of the properties of the unit classes and the individual features with data from radiometry, ISS, and VIMS provides information on their composition and possible provenance. We can use these correlations to also infer global distribution on regions not covered by SAR. This is particularly important, as SAR data will not provide complete coverage of Titan by the end of the Cassini

Saturn/Titan Rendezvous: A Solar-Sail Aerocapture Mission

NASA Technical Reports Server (NTRS)

Matloff, Gregory L.; Taylor, Travis; Powell, Conley

2004-01-01

A low-mass Titan orbiter is proposed that uses conservative or optimistic solar sails for all post-Earth-escape propulsion. After accelerating the probe onto a trans-Saturn trajectory, the sail is used parachute style for Saturn capture during a pass through Saturn's outer atmosphere. If the apoapsis of the Saturn-capture orbit is appropriate, the aerocapture maneuver can later be repeated at Titan so that the spacecraft becomes a satellite of Titan. An isodensity-atmosphere model is applied to screen aerocapture trajectories. Huygens/Cassini should greatly reduce uncertainties regarding the upper atmospheres of Saturn and Titan.

Energy Deposition Processes in Titan's Upper Atmosphere

NASA Technical Reports Server (NTRS)

Sittler, Edward C., Jr.; Bertucci, Cesar; Coates, Andrew; Cravens, Tom; Dandouras, Iannis; Shemansky, Don

2008-01-01

Most of Titan's atmospheric organic and nitrogen chemistry, aerosol formation, and atmospheric loss are driven from external energy sources such as Solar UV, Saturn's magnetosphere, solar wind and galactic cosmic rays. The Solar UV tends to dominate the energy input at lower altitudes of approximately 1100 km but which can extend down to approximately 400 km, while the plasma interaction from Saturn's magnetosphere, Saturn's magnetosheath or solar wind are more important at higher altitudes of approximately 1400 km, but the heavy ion plasma [O(+)] of approximately 2 keV and energetic ions [H(+)] of approximately 30 keV or higher from Saturn's magnetosphere can penetrate below 950km. Cosmic rays with energies of greater than 1 GeV can penetrate much deeper into Titan's atmosphere with most of its energy deposited at approximately 100 km altitude. The haze layer tends to dominate between 100 km and 300 km. The induced magnetic field from Titan's interaction with the external plasma can be very complex and will tend to channel the flow of energy into Titan's upper atmosphere. Cassini observations combined with advanced hybrid simulations of the plasma interaction with Titan's upper atmosphere show significant changes in the character of the interaction with Saturn local time at Titan's orbit where the magnetosphere displays large and systematic changes with local time. The external solar wind can also drive sub-storms within the magnetosphere which can then modify the magnetospheric interaction with Titan. Another important parameter is solar zenith angle (SZA) with respect to the co-rotation direction of the magnetospheric flow. Titan's interaction can contribute to atmospheric loss via pickup ion loss, scavenging of Titan's ionospheric plasma, loss of ionospheric plasma down its induced magnetotail via an ionospheric wind, and non-thermal loss of the atmosphere via heating and sputtering induced by the bombardment of magnetospheric keV ions and electrons. This

Titan. [Voyager IRIS observation of satellite atmosphere

NASA Technical Reports Server (NTRS)

Lunine, Jonathan I.

1990-01-01

Saturn's satellite Titan is the second-largest in the solar system. Its dense atmosphere is mostly molecular nitrogen with an admixture of methane, a surface pressure of 1.5 bars and a surface temperature of 94K. The fundamental driving force in the long-term evolution of Titan's atmosphere is the photolysis of methane in the stratosphere to form higher hydrocarbons and aerosols. The current rate of photolysis and undersaturation of methane in the lower troposphere suggests the presence of a massive ethane-methane-nitrogen ocean. The ocean evolves to a more ethane-rich state over geologic time, driving changes in the atmospheric thermal structure. An outstanding issue concerning Titan's earliest history is the origin of atmospheric nitrogen: was it introduced into Titan as molecular nitrogen or ammonia? Measurement of the argon-to-nitrogen ratio in the present atmosphere provides a diagnostic test of these competing hypotheses. Many of the questions raised by the Voyager encounters about Titan and its atmosphere can be adequately addressed only by an entry probe, such as that planned for the Cassini mission.

The Properties and Effects of Titan's Organic Haze

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; Young, Richard E. (Technical Monitor)

1997-01-01

Titan's organic haze is the the dominant absorber of solar energy in Titan's atmosphere, creating an anti-greenhouse effect. Its variation over time may have had important implications for Titan's surface temperature. The haze is potentially an important sink of photochemically produced carbon and nitrogen compounds. Laboratory simulations and microphysical models suggest that the haze is a sink for C of 4 x 10(exp 8)/ sq cm s, and a sink for N of 1 x 10(exp 8)sq cm s. The C sink is small compared to condensation of hydrocarbons but the sink for N is comparable to the total production rate of HCN. Because estimates of the eddy diffusion profile on Titan have been based on the HCN profile, inclusion of this additional sink for N will affect estimates for all transport processes in Titan's atmosphere.

Japan's electronic packaging technologies

NASA Technical Reports Server (NTRS)

Tummala, Rao R.; Pecht, Michael

1995-01-01

The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

Mapping the Methane and Aerosol Distributions within Titan's Troposphere: Complementing The Cassini/VIMS T90 Flyby of Titan

NASA Astrophysics Data System (ADS)

Young, Eliot

2012-10-01

Titan's atmosphere is mainly nitrogen gas with several trace constituents, including methane at the few percent level. The presence of methane has been a puzzle for decades, since the CH4 in Titan's atmosphere is expected to be destroyed by UV photolysis in ten million years or so. The source of Titan's atmospheric methane continues to be a major question. We propose a set of three STIS image cubes with the G750M grating at 0.62, 0.72 and 0.89 |*|m methane bands. These bands probe altitudes from the surface to 70 km; unlike CH4 bands at 1.6 or 2.3 |*|m, these cubes will provide a 3-D picture of Titan's troposphere {below 40 km}. The Cassini/VIMS visible channel has not been useful for this purpose for two reasons: its spectral resolution {about R=100} is coarse and its inconsistent background subtraction scheme that can lead to "stripes." HST/STIS resolves Titan's 1" disk into over 80 spatially resolved spectra, each with a spectral resolution greater than R=5000. STIS is a unique tool for mapping the 3-D distributions of CH4 and aerosols in Titan's troposphere.We request observations within a day of the Cassini flyby of Titan on April 5, 2013 around 21:40 UT in order to combine Cassini/VIMS and STIS mage cubes. Together, the visible {STIS} and IR {VIMS} image cubes will probe altitudes from the surface to the stratosphere {several hundred km}. The proposed STIS image cubes will provide the best tropospheric map of CH4 to date, relevant to surface/atmospheric coupling of CH4, latitudinal inhomogeneity of CH4 or aerosols, or the presence of condensates at low altitudes.

Facility Energy Decision System (FEDS) Assessment Report for US Army Garrison, Japan - Honshu Installations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kora, Angela R.; Brown, Daryl R.; Dixon, Douglas R.

2010-03-09

This report documents an assessment was performed by a team of engineers from Pacific Northwest National Laboratory (PNNL) under contract to the Installation Management Command (IMCOM) Pacific Region Office (PARO). The effort used the Facility Energy Decision System (FEDS) model to determine how energy is consumed at five U.S. Army Garrison-Japan (USAG-J) installations in the Honshu area, identify the most cost-effective energy retrofit measures, and calculate the potential energy and cost savings.

Titan's cloud seasonal activity from winter to spring with Cassini/VIMS

USGS Publications Warehouse

Rodriguez, S.; Le, Mouelic S.; Rannou, P.; Sotin, Christophe; Brown, R.H.; Barnes, J.W.; Griffith, C.A.; Burgalat, J.; Baines, K.H.; Buratti, B.J.; Clark, R.N.; Nicholson, P.D.

2011-01-01

Since Saturn orbital insertion in July 2004, the Cassini orbiter has been observing Titan throughout most of the northern winter season (October 2002-August 2009) and the beginning of spring, allowing a detailed monitoring of Titan's cloud coverage at high spatial resolution with close flybys on a monthly basis. This study reports on the analysis of all the near-infrared images of Titan's clouds acquired by the Visual and Infrared Mapping Spectrometer (VIMS) during 67 targeted flybys of Titan between July 2004 and April 2010.The VIMS observations show numerous sporadic clouds at southern high and mid-latitudes, rare clouds in the equatorial region, and reveal a long-lived cloud cap above the north pole, ubiquitous poleward of 60??N. These observations allow us to follow the evolution of the cloud coverage during almost a 6-year period including the equinox, and greatly help to further constrain global circulation models (GCMs). After 4. years of regular outbursts observed by Cassini between 2004 and 2008, southern polar cloud activity started declining, and completely ceased 1. year before spring equinox. The extensive cloud system over the north pole, stable between 2004 and 2008, progressively fractionated and vanished as Titan entered into northern spring. At southern mid-latitudes, clouds were continuously observed throughout the VIMS observing period, even after equinox, in a latitude band between 30??S and 60??S. During the whole period of observation, only a dozen clouds were observed closer to the equator, though they were slightly more frequent as equinox approached. We also investigated the distribution of clouds with longitude. We found that southern polar clouds, before disappearing in mid-2008, were systematically concentrated in the leading hemisphere of Titan, in particular above and to the east of Ontario Lacus, the largest reservoir of hydrocarbons in the area. Clouds are also non-homogeneously distributed with longitude at southern mid

Titan's "Hot Cross Bun": A Titan Laccolith?

NASA Astrophysics Data System (ADS)

Lopes, Rosaly M. C.; Stofan, E. R.; Wall, S. D.; Wood, C.; Kirk, R. L.; Lucas, A.; Mitchell, K. L.; Lunine, J. I.; Turtle, E. P.; Radebaugh, J.; Malaska, M.; Cassini RADAR Team

2012-10-01

Cassini’s RADAR instrument acquired Synthetic Aperture Radar data during the T83 flyby on May 22, 2012. The data showed a feature centered at 38.5N, 203W that resembles a “hot cross bun”. This type of feature has not been seen on Titan before, even though 52% of Titan’s surface has been imaged using SAR. The feature, approximately 100 km across, is mostly radar bright but the cross pattern, interpreted to be extensional fractures, located roughly at the center of the brighter area, appears darker at radar wavelengths (2.3 cm). Radar illumination of the image indicates that the fractures are lower in elevation than the surrounding bright region. The morphology of the region is markedly similar to that of a 30-km dome-shaped feature on Venus that lies at the summit of the Kunapipi volcano. The Venus feature is interpreted to be the result of intrusion of magma at the summit of the volcano [1]. A similar feature, interpreted as a laccolith, is seen on the Moon near the crater Ramsden [2]. The lunar feature, imaged by the Lunar Reconnaissance Orbiter, shows the cross-shaped depression over a 300 m high rise. No topographic data for the feature on Titan are available at this time, but the morphology seen by the SAR data suggests that the feature may have been formed by material pushing up from below. Laccoliths form when an igneous intrusion splits apart two strata, resulting in a domeline structure. This previously unknown type of structure on Titan may be yet another indication of cryovolcanism. [1] Stofan, E.R., et al, Icarus, 152, 75-95, 2001. [2] Wichman, R.W. and Schultz, P. H. (1996). Icarus, 122, Issue 1, July 1996, pages 193-199. doi:10.1006/icar.1996.0118

The lakes of Titan

USGS Publications Warehouse

Stofan, E.R.; Elachi, C.; Lunine, J.I.; Lorenz, R.D.; Stiles, B.; Mitchell, K.L.; Ostro, S.; Soderblom, L.; Wood, C.; Zebker, H.; Wall, S.; Janssen, M.; Kirk, R.; Lopes, R.; Paganelli, F.; Radebaugh, J.; Wye, L.; Anderson, Y.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.; Paillou, P.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Vetrella, S.; West, R.

2007-01-01

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70?? north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table. ??2007 Nature Publishing Group.

A Titanic Labyrinth

NASA Image and Video Library

2016-07-29

This synthetic-aperture radar image was obtained by NASA's Cassini spacecraft during its T-120 pass over Titan's southern latitudes on June 7, 2016. The image is centered near 47 degrees south, 153 degrees west. It covers an area of 87 by 75 miles (140 by 120 kilometers) and has a resolution of about 1,300 feet (400 meters). Radar illuminates the scene from the left at a 35-degree incidence angle. The features seen here are an excellent example of "labyrinth terrain." Labyrinth terrains on Titan are thought to be higher areas that have been cut apart by rivers of methane, eroded or dissolved as they were either lifted up or left standing above as the region around them lowered. (Other examples of labyrinth terrain can be seen in PIA10219.) In this image, several obvious valley systems have developed, draining liquids from methane rainfall toward the southeast (at top). Several of these systems are near parallel (running from upper left to lower right), suggesting that either the geological structure of the surface or the local topographic gradient (the general slope across the area) may be influencing their direction. Also presented here is an annotated version of the image, along with an aerial photograph of a region in southern Java known as Gunung Kidul that resembles this Titan labyrinth. This region is limestone that has been dissolved and eroded by water, creating a system of canyons called polygonal karst. Like on Titan, the canyons show a trend from upper left to lower right, in this case controlled by faults or joints. (Java photo from Haryono and Day, Journal of Cave and Karst Studies 66 (2004) 62-69, courtesy of Eko Haryono.) http://photojournal.jpl.nasa.gov/catalog/PIA20708

New Materials for Smart Structures: a US: Japan Global Initiative

DTIC Science & Technology

2004-03-01

realization of the MPB in the Gallate:Scandate system and in the modified bismuth lanthanum ferrate lead titanate systems. A major puzzle in BiFeO3 which has...magnetization. A new major clue as to the origin of the high switchable polarization is provided by our most recent work on the modified bismuth lanthanum ...ferrate: gallate solid solutions with MPBs. In suitable composition switchability is only possible with limited electrode in a larger disk, and the fully

Accelerated Application Development: The ORNL Titan Experience

DOE PAGES

Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; ...

2015-05-09

The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

Accelerated application development: The ORNL Titan experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joubert, Wayne; Archibald, Rick; Berrill, Mark

2015-08-01

The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

Titan's ion exosphere observed from Voyager 1

NASA Technical Reports Server (NTRS)

Hartle, R. E.; Sittler, E. C., Jr.; Ogilvie, K. W.; Scudder, J. D.; Lazarus, A. J.; Atreya, S. K.

1982-01-01

The plasma wake surrounding Titan in Saturn's rotating magnetosphere is characterized by a plasma which is denser and cooler than the surrounding subsonic magnetospheric plasma, and which is produced by the deflection of magnetospheric plasma around Titan and the addition of exospheric ions picked up by the rotating magnetosphere. A resemblance to the interaction between the solar wind and Venus is shown for the case of ion pickup in the ion exosphere outside Titan's magnetic tail and ion flow within the boundaries of the tail as Saturn's rotating magnetosphere interacts with Titan. The boundary of the tail is indicated by a sharp reduction in the flux of high-energy electrons, which are removed by inelastic scattering with the atmosphere and centrifugal drift produced when the electrons traverse the magnetic field draped around Saturn.

Cyanide Soap? Dissolved material in Titan's Seas

NASA Astrophysics Data System (ADS)

Lorenz, R. D.; Lunine, J. I.; Neish, C. D.

2011-10-01

Although it is evident that Titan's lakes and seas are dominated by ethane, methane, nitrogen, and (in some models) propane, there is divergence on the predicted relative abundance of minor constituents such as nitriles and C-4 alkanes. Nitriles such as hydrogen cyanide and acetonitrile, which have a significant dipole moment, may have a disproportionate influence on the dielectric properties of Titan seas and may act to solvate polar molecules such as water ice. The hypothesis is offered that such salvation may act to enhance the otherwise negligible solubility of water ice bedrock in liquid hydrocarbons. Such enhanced solubility may permit solution erosion as a formation mechanism for the widespread pits and apparently karstic lakes on Titan. Prospects for testing this hypothesis in the laboratory, and with measurements on Titan, will be discussed.

Titan's Stratospheric Water Vapor profile from Cassini CIRS far-infrared Spectra

NASA Astrophysics Data System (ADS)

Cottini, V.; Nixon, C. A.; Achterberg, R. K.; Gorius, N.; Coustenis, A.; Irwin, P. G. J.; Anderson, C. M.; Bjoraker, G. L.; Jennings, D. E.; Flasar, F. M.; Ansty, T. M.

2017-09-01

In this work we present an update of water vapor abundance in Titan's stratosphere through modeling of its emission lines present in the spectral range (100 - 300 cm-1) observed by the Cassini Composite Infrared Spectrometer (CIRS) far-IR Focal Plane 1 (FP1) detector. We model and analyze high spectral resolution (0.5 cm-1) disk and limb observations acquired from December 2004 to December 2016 to determine the water mixing ratio profile. Nadir data and limb data acquired up to 2011 and pointing at two altitudes in Titan's stratosphere (125 and 225 km) have been previously used in [1] to detect water vapor and retrieve its abundance at two limb altitudes. Few years of more data and improved calibrations are now available to further investigate water vapor. In particular, three far-infrared limb integrations were planned and acquired in 2014 and 2016 with CIRS staring at a single altitude (175 km) for longer time. These new data provided us with one more altitude point to derive the water vapor abundance and improve its retrieved vertical profile, increasing significantly the science results. These results will also be compared to previous results and to the latest photochemical models of Titan's oxygen species.

Location and size of flux ropes in Titan's ionosphere

NASA Astrophysics Data System (ADS)

Martin, C.; Arridge, C. S.; Badman, S. V.; Dieval, C.

2017-12-01

Cassini magnetometer data was surveyed during Titan flybys to find 73 instances of flux rope signatures. A force free flux rope model was utilised to obtain the radii, maximum magnetic field and flux content of flux ropes that adhere to the force-free assumptions. We find that flux ropes at Titan are similar in size in km and flux content to the giant flux ropes identified at Venus, with a median radii of 280 km and an inter-quartile range of 270 km, a median maximum magnetic field of 8 nT with an inter-quartile range of 7 nT and a median flux content of 76 Wb with a large inter-quartile range of 250 Wb. We additionally investigate the occurrence of flux ropes with respect to the Sun-lit facing hemisphere (zenith angle) and the ram-side of Titan within Saturn's corotating magnetosphere (angle of attack of the incoming plasma flow). We find that flux ropes are more commonly detected in Sun-lit areas of Titan's ionosphere, as well as the ram-side of Titan. We see a statistically-significant absence of flux ropes in all SLT sectors in the night side of Titan and the anti-ram side of Titan. We also comment on the physical mechanisms associated with the production of these flux ropes, with particular attention on the variability of Titan's environment in Saturn's magnetosphere.

Experimental basis for a Titan probe organic analysis

NASA Technical Reports Server (NTRS)

Mckay, C. P.; Scattergood, T. W.; Borucki, W. J.; Kasting, J. F.; Miller, S. L.

1986-01-01

The recent Voyager flyby of Titan produced evidence for at least nine organic compounds in that atmosphere that are heavier than methane. Several models of Titan's atmosphere, as well as laboratory simulations, suggest the presence of organics considerably more complex that those observed. To ensure that the in situ measurements are definitive with respect to Titan's atmosphere, experiment concepts, and the related instrumentation, must be carefully developed specifically for such a mission. To this end, the possible composition of the environment to be analyzed must be bracketed and model samples must be provided for instrumentation development studies. Laboratory studies to define the optimum flight experiment and sampling strategy for a Titan entry probe are currently being conducted. Titan mixtures are being subjected to a variety of energy sources including high voltage electron from a DC discharge, high current electric shock, and laser detonation. Gaseous and solid products are produced which are then analyzed. Samples from these experiements are also provided to candidate flight experiments as models for instrument development studies. Preliminary results show that existing theoretical models for chemistry in Titan's atmosphere cannot adequetely explain the presence and abundance of all trace gases observed in these experiments.

Japan’s Roles in U.S. National Security Strategy: Strategic Ally and Economic Adversary

DTIC Science & Technology

1991-06-01

the most substantial contributors to United Nations organizations, and are among the most influential members of the World Bank, the International...postwar occupation . This dominance allowed the U.S. to pursue broad policy objectives which included the assurance "...that Japan will not again...tive."𔃼 2 In effect, the vanquished nation yielded its des- tiny to occupation authorities. For all practical purposes, this equated to American

U.S.-Japan Quake Prediction Research

NASA Astrophysics Data System (ADS)

Kisslinger, Carl; Mikumo, Takeshi; Kanamori, Hiroo

For the seventh time since 1964, a seminar on earthquake prediction has been convened under the U.S.-Japan Cooperation in Science Program. The purpose of the seminar was to provide an opportunity for researchers from the two countries to share recent progress and future plans in the continuing effort to develop the scientific basis for predicting earthquakes and practical means for implementing prediction technology as it emerges. Thirty-six contributors, 15 from Japan and 21 from the U.S., met in Morro Bay, Calif.September 12-14. The following day they traveled to nearby sections of the San Andreas fault, including the site of the Parkfield prediction experiment. The conveners of the seminar were Hiroo Kanamori, Seismological Laboratory, California Institute of Technology (Caltech), for the U.S., and Takeshi Mikumo, Disaster Prevention Research Institute, Kyoto University, for Japan . Funding for the participants came from the U.S. National Science Foundation and the Japan Society forthe Promotion of Science, supplemented by other agencies in both countries.

Titan's organic chemistry: Results of simulation experiments

NASA Technical Reports Server (NTRS)

Sagan, Carl; Thompson, W. Reid; Khare, Bishun N.

1992-01-01

Recent low pressure continuous low plasma discharge simulations of the auroral electron driven organic chemistry in Titan's mesosphere are reviewed. These simulations yielded results in good accord with Voyager observations of gas phase organic species. Optical constants of the brownish solid tholins produced in similar experiments are in good accord with Voyager observations of the Titan haze. Titan tholins are rich in prebiotic organic constituents; the Huygens entry probe may shed light on some of the processes that led to the origin of life on Earth.

Geomorphic Units on Titan

NASA Astrophysics Data System (ADS)

Lopes, R. M. C.; Malaska, M. J.; Schoenfeld, A.; Birch, S. P.; Hayes, A. G., Jr.

2014-12-01

The Cassini-Huygens mission has revealed the surface of Titan in unprecedented detail. The Synthetic Aperture Radar (SAR) mode on the Cassini Titan Radar Mapper is able to penetrate clouds and haze to provide high resolution (~350 m spatial resolution at best) views of the surface geology. The instrument's other modes (altimetry, scatterometry, radiometry) also provide valuable data for interpreting the geology, as do other instruments on Cassini, in particular, the Imaging Science Subsystem (ISS) and the Visual and Infrared Mapping Spectrometer (VIMS). Continuing the initial work described in Lopes et al. (2010, Icarus, 212, 744-750), we have established the major geomorphologic unit classes on Titan using data from flybys Ta through T92 (October 2004-July 2013). We will present the global distribution of the major classes of units and, where there are direct morphological contacts, describe how these classes of units relate to each other in terms of setting and emplacement history. The classes of units are mountainous/hummocky terrains, plains, dunes, labyrinthic terrains and lakes. The oldest classes of units are the mountainous/hummocky and the labyrinthic terrains. The mountainous/hummocky terrains consist of mountain chains and isolated radar-bright terrains. The labyrinthic terrains consist of highly incised dissected plateaux with medium radar backscatter. The plains are younger than both mountainous/hummocky and labyrinthic unit classes. Dunes and lakes are the youngest unit classes on Titan; no contact is observed between the dunes and lakes but it is likely that both processes are still active. We have identified individual features such as craters, channels, and candidate cryovolcanic features. Characterization and comparison of the properties of the unit classes and the individual features with data from radiometry, ISS, and VIMS provides information on their composition and possible provenance. We can use these correlations to also infer global

Geomorphic Units on Titan

NASA Astrophysics Data System (ADS)

Lopes, Rosaly; Malaska, Michael; Schoenfeld, Ashley; Birch, Samuel; Hayes, Alexander; Solomonidou, Anezina; Radebaugh, Jani

2015-04-01

The Cassini-Huygens mission has revealed the surface of Titan in unprecedented detail. The Synthetic Aperture Radar (SAR) mode on the Cassini Titan Radar Mapper is able to penetrate clouds and haze to provide high resolution (~350 m spatial resolution at best) views of the surface geology. The instrument's other modes (altimetry, scatterometry, radiometry) also provide valuable data for interpreting the geology, as do other instruments on Cassini, in particular, the Imaging Science Subsystem (ISS) and the Visual and Infrared Mapping Spectrometer (VIMS). Continuing the initial work described in Lopes et al. (2010, Icarus, 212, 744-750), we have established the major geomorphologic unit classes on Titan using data from flybys Ta through T92 (October 2004-July 2013). We will present the global distribution of the major classes of units and, where there are direct morphological contacts, describe how these classes of units relate to each other in terms of setting and emplacement history. The classes of units are mountainous/hummocky terrains, plains, dunes, labyrinthic terrains and lakes. The oldest classes of units are the mountainous/hummocky and the labyrinthic terrains. The mountainous/hummocky terrains consist of mountain chains and isolated radar-bright terrains. The labyrinthic terrains consist of highly incised dissected plateaux with medium radar backscatter. The plains are younger than both mountainous/hummocky and labyrinthic unit classes. Dunes and lakes are the youngest unit classes on Titan; no contact is observed between the dunes and lakes but it is likely that both processes are still active. We have identified individual features such as craters, channels, and candidate cryovolcanic features. Characterization and comparison of the properties of the unit classes and the individual features with data from radiometry, ISS, and VIMS provides information on their composition and possible provenance. We can use these correlations to also infer global

A Three-Dimensional View of Titan's Surface Features from Cassini RADAR Stereogrammetry

NASA Astrophysics Data System (ADS)

Kirk, R. L.; Howington-Kraus, E.; Redding, B. L.; Becker, T. L.; Lee, E. M.; Stiles, B. W.; Hensley, S.; Hayes, A.; Lopes, R. M.; Lorenz, R. D.; Mitchell, K. L.; Radebaugh, J.; Paganelli, F.; Soderblom, L. A.; Stofan, E. R.; Wood, C. A.; Wall, S. D.; Cassini RADAR Team

2008-12-01

us supplement automatic image matching with interactive measurements where the former fails. We are collecting DTMs of all usable image pairs and will present the most interesting results. Examples of geologic questions that may be addressed are: What is the relation between Ganesa and surrounding features? Is it a dome or shield? Can the height of Titan's dunes be measured, and what is the relief of the bright "islands" that appear to divert the dunes? How high are the mountains of Xanadu and what gradients drive the channels between them? What are the relative and absolute height relations between seas and lakes of different types, and what does this tell us about the "hydro(carbono)logic" cycle of precipitation, evaporation, and surface and subsurface fluid flow?

Production and distribution of scientific and technical databases - Comparison among Japan, US and Europe

NASA Astrophysics Data System (ADS)

Onodera, Natsuo; Mizukami, Masayuki

This paper estimates several quantitative indice on production and distribution of scientific and technical databases based on various recent publications and attempts to compare the indice internationally. Raw data used for the estimation are brought mainly from the Database Directory (published by MITI) for database production and from some domestic and foreign study reports for database revenues. The ratio of the indice among Japan, US and Europe for usage of database is similar to those for general scientific and technical activities such as population and R&D expenditures. But Japanese contributions to production, revenue and over-countory distribution of databases are still lower than US and European countries. International comparison of relative database activities between public and private sectors is also discussed.

US Climate Variability and Predictability (CLIVAR) Project- Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patterson, Mike

The US CLIVAR Project Office administers the US CLIVAR Program with its mission to advance understanding and prediction of climate variability and change across timescales with an emphasis on the role of the ocean and its interaction with other elements of the Earth system. The Project Office promotes and facilitates scientific collaboration within the US and international climate and Earth science communities, addressing priority topics from subseasonal to centennial climate variability and change; the global energy imbalance; the ocean’s role in climate, water, and carbon cycles; climate and weather extremes; and polar climate changes. This project provides essential one-year supportmore » of the Project Office, enabling the participation of US scientists in the meetings of the US CLIVAR bodies that guide scientific planning and implementation, including the scientific steering committee that establishes program goals and evaluates progress of activities to address them, the science team of funded investigators studying the ocean overturning circulation in the Atlantic, and two working groups tackling the priority research topics of Arctic change influence on midlatitude climate and weather extremes and the decadal-scale widening of the tropical belt.« less

Widespread morning drizzle on Titan.

PubMed

Adámkovics, Máté; Wong, Michael H; Laver, Conor; de Pater, Imke

2007-11-09

Precipitation is expected in Titan's atmosphere, yet it has not been directly observed, and the geographical regions where rain occurs are unknown. Here we present near-infrared spectra from the Very Large Telescope and W. M. Keck Observatories that reveal an enhancement of opacity in Titan's troposphere on the morning side of the leading hemisphere. Retrieved extinction profiles are consistent with condensed methane in clouds at an altitude near 30 kilometers and concomitant methane drizzle below. The moisture encompasses the equatorial region over Titan's brightest continent, Xanadu. Diurnal temperature gradients that cause variations in methane relative humidity, winds, and topography may each be a contributing factor to the condensation mechanism. The clouds and precipitation are optically thin at 2.0 micrometers, and models of "subvisible" clouds suggest that the droplets are 0.1 millimeter or larger.

NREL: U.S. Life Cycle Inventory Database - Project Management Team

Science.gov Websites

Project Management Team Information about the U.S. Life Cycle Inventory (LCI) Database project management team is listed on this page. Additional project information is available about the U.S. LCI Mechanical Engineering, Colorado State University Professional History Michael has worked as a Senior

Charged particle tracking at Titan, and further applications

NASA Astrophysics Data System (ADS)

Bebesi, Zsofia; Erdos, Geza; Szego, Karoly

2016-04-01

We use the CAPS ion data of Cassini to investigate the dynamics and origin of Titan's atmospheric ions. We developed a 4th order Runge-Kutta method to calculate particle trajectories in a time reversed scenario. The test particle magnetic field environment imitates the curved magnetic environment in the vicinity of Titan. The minimum variance directions along the S/C trajectory have been calculated for all available Titan flybys, and we assumed a homogeneous field that is perpendicular to the minimum variance direction. Using this method the magnetic field lines have been calculated along the flyby orbits so we could select those observational intervals when Cassini and the upper atmosphere of Titan were magnetically connected. We have also taken the Kronian magnetodisc into consideration, and used different upstream magnetic field approximations depending on whether Titan was located inside of the magnetodisc current sheet, or in the lobe regions. We also discuss the code's applicability to comets.

Specular reflection on Titan: Liquids in Kraken Mare

USGS Publications Warehouse

Stephan, Katrin; Jaumann, Ralf; Brown, Robert H.; Soderblom, Jason M.; Soderblom, Laurence A.; Barnes, Jason W.; Sotin, Christophe; Griffith, Caitlin A.; Kirk, Randolph L.; Baines, Kevin H.; Buratti, Bonnie J.; Clark, Roger N.; Lytle, Dyer M.; Nelson, Robert M.; Nicholson, Phillip D.

2010-01-01

After more than 50 close flybys of Titan by the Cassini spacecraft, it has become evident that features similar in morphology to terrestrial lakes and seas exist in Titan's polar regions. As Titan progresses into northern spring, the much more numerous and larger lakes and seas in the north-polar region suggested by Cassini RADAR data, are becoming directly illuminated for the first time since the arrival of the Cassini spacecraft. This allows the Cassini optical instruments to search for specular reflections to provide further confirmation that liquids are present in these evident lakes. On July 8, 2009 Cassini VIMS detected a specular reflection in the north-polar region of Titan associated with Kraken Mare, one of Titan's large, presumed seas, indicating the lake's surface is smooth and free of scatterers with respect to the wavelength of 5 μm, where VIMS detected the specular signal, strongly suggesting it is liquid.

Organic chemistry on Titan

NASA Technical Reports Server (NTRS)

Chang, S.; Scattergood, T.; Aronowitz, S.; Flores, J.

1978-01-01

Observations of nonequilibrium phenomena on the Saturn satellite Titan indicate the occurrence of organic chemical evolution. Greenhouse and thermal inversion models of Titan's atmosphere provide environmental constraints within which various pathways for organic chemical synthesis are assessed. Experimental results and theoretical modeling studies suggest that the organic chemistry of the satellite may be dominated by two atmospheric processes: energetic-particle bombardment and photochemistry. Reactions initiated in various levels of the atmosphere by cosmic ray, Saturn wind, and solar wind particle bombardment of a CH4 - N2 atmospheric mixture can account for the C2-hydrocarbons, the UV-visible-absorbing stratospheric haze, and the reddish color of the satellite. Photochemical reactions of CH4 can also account for the presence of C2-hydrocarbons. In the lower Titan atmosphere, photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. Hot H-atom reactions initiated by photo-dissociation of NH3 can couple the chemical reactions of NH3 and CH4 and produce organic matter.

Mapping products of Titan's surface: Chapter 19

USGS Publications Warehouse

Stephan, Katrin; Jaumann, Ralf; Karkoschka, Erich; Kirk, Randolph L.; Barnes, Jason W.; Tomasko, Martin G.; Turtle, Elizabeth P.; Le Corre, Lucille; Langhans, Mirjam; Le Mouélic, Stéphane; Lorenz, Ralph D.; Perry, Jason; Brown, Robert; Lebreton, Jean-Pierre; Waite, J. Hunter

2010-01-01

Remote sensing instruments aboard the Cassini spacecraft have been observed the surface of Titan globally in the infrared and radar wavelength ranges as well as locally by the Huygens instruments revealing a wealth of new morphological features indicating a geologically active surface. We present a summary of mapping products of Titan's surface derived from data of the remote sensing instruments onboard the Cassini spacecraft (ISS, VIMS, RADAR) as well as the Huygens probe (DISR) that were achieved during the nominal Cassini mission including an overview of Titan's recent nomenclature.

Outline of an Ancient Sea on Titan

NASA Image and Video Library

2012-10-16

This image from NASA Cassini spacecraft shows an ancient southern sea that used to sprawl out near the south pole of Saturn moon Titan. Within this basin is the largest present-day lake in Titan southern hemisphere, Ontario Lacus.

Cratering on Titan: A Pre-Cassini Perspective

NASA Technical Reports Server (NTRS)

Lorenz, R. D.

1997-01-01

The NASA-ESA Cassini mission, comprising a formidably instrumented orbiter and parachute-borne probe to be launched this October, promises to reveal a crater population on Titan that has been heretofore hidden by atmospheric haze. This population on the largest remaining unexplored surface in the solar system will be invaluable in comparative planetological studies, since it introduces evidence of the atmospheric effects of cratering on an icy satellite. Here, I highlight some impact features we may hope to find and could devote some modeling effort toward. Titan in a Nutshell: Radius= 2575 km. Density= 1880 kg/cubic m consistent with rock-ice composition. Surface pressure = 1.5 bar. Surface gravity = 1.35 m/square s Atmosphere -94% N2 6% CH, Surface temperature = 94K Tropopause temperature = 70K at 40 km alt. Probable liquid hydrocarbon deposits exist on or near the surface.Titan in a Nutshell: Radius= 2575 km. Density= 1880 kg/cubic m consistent with rock-ice composition. Surface pressure = 1.5 bar. Surface gravity = 1.35 m/square s; Atmosphere about 94% N2 6% CH, Surface temperature = 94K Tropopause temperature = 70K at 40 km alt. Probable liquid hydrocarbon deposits exist on or near the surface. Titan is comparable to Callisto and Ganymede for strength/gravity, Mars/Earth/Venus for atmospheric interaction, and Hyperion, Rhea, and Iapetus for impactor distribution. The leading/trailing asymmetry of crater density from heliocentric impactors is expected to be about 5-6, in the absence of resurfacing. Any Saturnocentric impactor population is likely to alter this. In particular the impact disruption of Hyperion is noted; because of the 3:4 orbital resonance with Titan, fragments from the proto-Hyperion breakup would have rapidly accreted onto Titan. Titan's resurfacing history is of course unknown. The disruption of impactors into fragments that individually create small craters is expected to occur. A crude estimate suggests a maximum separation of about 2 km

Cratering on Titan: A Pre-Cassini Perspective

NASA Astrophysics Data System (ADS)

Lorenz, R. D.

1997-01-01

The NASA-ESA Cassini mission, comprising a formidably instrumented orbiter and parachute-borne probe to be launched this October, promises to reveal a crater population on Titan that has been heretofore hidden by atmospheric haze. This population on the largest remaining unexplored surface in the solar system will be invaluable in comparative planetological studies, since it introduces evidence of the atmospheric effects of cratering on an icy satellite. Here, I highlight some impact features we may hope to find and could devote some modeling effort toward. Titan in a Nutshell: Radius= 2575 km. Density= 1880 kg/cubic m consistent with rock-ice composition. Surface pressure = 1.5 bar. Surface gravity = 1.35 m/square s Atmosphere -94% N2 6% CH, Surface temperature = 94K Tropopause temperature = 70K at 40 km alt. Probable liquid hydrocarbon deposits exist on or near the surface.Titan in a Nutshell: Radius= 2575 km. Density= 1880 kg/cubic m consistent with rock-ice composition. Surface pressure = 1.5 bar. Surface gravity = 1.35 m/square s; Atmosphere about 94% N2 6% CH, Surface temperature = 94K Tropopause temperature = 70K at 40 km alt. Probable liquid hydrocarbon deposits exist on or near the surface. Titan is comparable to Callisto and Ganymede for strength/gravity, Mars/Earth/Venus for atmospheric interaction, and Hyperion, Rhea, and Iapetus for impactor distribution. The leading/trailing asymmetry of crater density from heliocentric impactors is expected to be about 5-6, in the absence of resurfacing. Any Saturnocentric impactor population is likely to alter this. In particular the impact disruption of Hyperion is noted; because of the 3:4 orbital resonance with Titan, fragments from the proto-Hyperion breakup would have rapidly accreted onto Titan. Titan's resurfacing history is of course unknown. The disruption of impactors into fragments that individually create small craters is expected to occur. A crude estimate suggests a maximum separation of about 2 km

Titan Explorer: The Next Step in the Exploration of a Mysterious World

NASA Technical Reports Server (NTRS)

Levine, Joel S.; Wright, Henry S.

2005-01-01

The Titan Explorer Mission outlined in this report is a proposed next step in the exploration of Titan, following the highly successful Huygens Titan probe of 2005. The proposed Titan Explorer Mission consists of an Orbiter and an Airship that traverses the atmosphere of Titan and can land on its surface. The Titan Explorer Mission is science driven and addresses some of the fundamental questions about the atmosphere, surface and evolution of Titan, which will add to our understanding of the origin and evolution of life on Earth and assess the likelihood of life elsewhere in the Solar System.

12th US-Japan Seminar: Many Body Quantum Systems from Quantum Gases to Metrology and Information Processing. Held in Madison, Wisconsin on 20-24 September 2015

DTIC Science & Technology

2016-06-03

Ultracold Atoms 5:10 Zelevinsky Ye Inouye High-precision spectroscopy with two-body quantum systems Low entropy quantum gas of polar molecules New limit...12th US-Japan Seminar: Many Body Quantum Systems from Quantum Gases to Metrology and Information Processing Support was provided for The 12th US...Japan Seminar on many body quantum systems which was held in Madison, Wisconsin from September 20 to 24, 2015 at the Monona Terrace Convention Center

Working Toward Seamless Infrared Maps of Titan

NASA Image and Video Library

2016-03-24

Each of these two montages shows four synthetic views of Titan created using data acquired by NASA Cassini spacecraft between 2004 and 2015. With each flyby, a brief opportunity to add small pieces to the overall mapping coverage of Titan.

Solar Electric and Chemical Propulsion for a Titan Mission

NASA Technical Reports Server (NTRS)

Cupples, Michael; Green, Shaun E.; Donahue, Benjamin B.; Coverstone, Victoria L.

2005-01-01

Systems analyses were performed for a Titan Explorer Mission characterized by Earth-Saturn transfer stages using solar electric power generation and propulsion systems for primary interplanetary propulsion, and chemical propulsion for capture at Titan. An examination of a range of system factors was performed to determine their effect on the payload delivery capability to Titan. The effect of varying launch vehicle type, solar array power level, ion thruster number, specific impulse, trip time, and Titan capture stage chemical propellant choice was investigated. The major purpose of the study was to demonstrate the efficacy of applying advanced ion propulsion system technologies like NASA's Evolutionary Xenon Thruster (NEXT), coupled with state-of-the-art (SOA) and advanced chemical technologies to a Flagship class mission. This study demonstrated that a NASA Design Reference Mission (DRM) payload of 406 kg could be successfully delivered to Titan using the baseline advanced ion propulsion system in conjunction with SOA chemical propulsion for Titan capture. In addition, the SEPS/Chemical system of this study is compared to an all- chemical NASA DRM mission. Results showed that the NEXT- based SEPS/Chemical system was able to deliver the required payload to Titan in 5 years less transfer time and on a smaller launch vehicle than the SOA chemical option.

Titania bound sodium titanate ion exchanger

DOEpatents

DeFilippi, Irene C. G.; Yates, Stephen Frederic; Shen, Jian-Kun; Gaita, Romulus; Sedath, Robert Henry; Seminara, Gary Joseph; Straszewski, Michael Peter; Anderson, David Joseph

1999-03-23

This invention is method for preparing a titania bound ion exchange composition comprising admixing crystalline sodium titanate and a hydrolyzable titanium compound and, thereafter drying the titania bound crystalline sodium titanate and subjecting the dried titania bound ion exchange composition to optional compaction and calcination steps to improve the physical strength of the titania bound composition.

The First Year of Cassini RADAR Observations of Titan

NASA Astrophysics Data System (ADS)

Elachi, C.; Lorenz, R. D.

2005-12-01

Titan`s atmosphere is essentially transparent to Radar, making it an ideal technique to study Titan`s surface. Cassini`s Titan Radar Mapper operates as a passive radiometer, scatterometer, altimeter, and synthetic aperture radar (SAR). Here we review data from four fly-bys in the first year of Cassini`s tour (Ta: October 2004, T3: February 2005, T7: September 2005, and T8: October 2005.) Early SAR images from Ta and T3 (showing < 3% of Titan`s surface) reveal that Titan is geologically young and complex (see Elachi et al., 2005, Science 13, 970-4). Significant variations were seen between the range of features seen in the Ta swath (centered at ~50N, 80W) and T3 (~ 30N, 70W) : the large-scale radiometric properties also differed, with T3 being radar-brighter. A variety of features have been identified in SAR, including two large impact craters, cryovolcanic flows and a probable volcanic dome. Dendritic and braided radar-bright sinuous channels, some 180km long, are evidence of fluvial activity. `Cat scratches`, arrays of linear dark features seem most likely to be Aeolian. Radar provides unique topographic information on Titan`s landscape e.g. the depth of the 80km crater observed in T3 can be geometrically determined to be around 1300m deep. Despite the shallow large-scale slopes indicated in altimetry to date, many small hills are seen in T3. Scatterometry and radiometry maps provide large-scale classification of surface types and polarization and incidence angle coverage being assembled will constrain dielectric and scattering properties of the surface. Judging from the TA/T3 diversity, we expect further variations in the types and distribution of surface materials and geologic features in T7, which spans a wide range of Southern latitudes. T8 SAR will cover a near-equatorial dark region, including the landing site of the Huygens probe.

Delays in clinical development of neurological drugs in Japan.

PubMed

Ikeda, Masayuki

2017-06-28

The delays in the approval and development of neurological drugs between Japan and other countries have been a major issue for patients with neurological diseases. The objective of this study was to analyze factors contributing to the delay in the launching of neurological drugs in Japan. We analyzed data from Japan and the US for the approval of 42 neurological drugs, all of which were approved earlier in the US than in Japan, and examined the potential factors that may cause the delay of their launch. Introductions of the 42 drugs in Japan occurred at a median of 87 months after introductions in the US. The mean review time of new drug applications for the 20 drugs introduced in Japan in January 2011 or later (15 months) was significantly shorter than that for the other 22 drugs introduced in Japan in December 2010 or earlier (24 months). The lag in the Japan's review time behind the US could not explain the approval delays. In the 31 of the 42 drugs, the application data package included overseas data. The mean review time of these 31 drugs (17 months) was significantly shorter than that of the other 11 drugs without overseas data (26 months). The mean approval lag behind the US of the 31 drugs (78 months) was also significantly shorter than that of the other 11 drugs (134 months). These results show that several important reforms in the Japanese drug development and approval system (e.g., inclusion of global clinical trial data) have reduced the delays in the clinical development of neurological drugs.

A Rover Concept for Exploring the Surface of Titan

NASA Astrophysics Data System (ADS)

Balint, T. S.; Shirley, J. H.; Schriener, T. M.

2005-12-01

Titan is one of the premier targets for future in-situ exploration in the outer solar system, as unique "pre-biotic" organic chemical processes may be presently occurring at its surface. A mission to the surface of Titan is not as technically difficult as one to Europa; Titan's atmosphere allows for aerobraking descents, the radiation environment is not a mission-critical factor, and the organic materials we want to sample should be widely distributed (and easily accessible). The recent Titan landing by the Huygens Probe has focused considerable scientific interest on this remarkable body, and future missions to Titan are under consideration. We evaluated a Titan Rover mission concept that would have the capability to survive on Titan's surface for a period of 3 terrestrial years. This long mission lifetime is enabled by employing a radioisotope power system (RPS). To minimize costs and use as much flight heritage as possible, we began by assuming that system masses, dimensions, and instrumentation would be comparable to those of the Mars Surface Lander (MSL). We found that a rover configuration with a 110 W (electric) power system and four 1.5 m diameter inflatable wheels could potentially enable traverse distances up to ~500 km, depending on science and mission requirements, surface environments, and the capability of the autonomous navigation system employed. Direct to Earth communication would simplify the mission by removing the need for a relay orbiter. We will describe our strawman instrument payload and rover subsystems. Trades between the potentially available RPS systems (RTG, Advanced RTG, TPV, SRG, Advanced Stirling and Brayton RPSs) will be outlined. While many possible approaches exist for Titan in-situ exploration, the Titan rover concept presented here could provide a scientifically interesting and programmatically affordable solution.

Superrotation on Venus, on Titan, and Elsewhere

NASA Astrophysics Data System (ADS)

Read, Peter L.; Lebonnois, Sebastien

2018-05-01

The superrotation of the atmospheres of Venus and Titan has puzzled dynamicists for many years and seems to put these planets in a very different dynamical regime from most other planets. In this review, we consider how to define superrotation objectively and explore the constraints that determine its occurrence. Atmospheric superrotation also occurs elsewhere in the Solar System and beyond, and we compare Venus and Titan with Earth and other planets for which wind estimates are available. The extreme superrotation on Venus and Titan poses some difficult challenges for numerical models of atmospheric circulation, much more difficult than for more rapidly rotating planets such as Earth or Mars. We consider mechanisms for generating and maintaining a superrotating state, all of which involve a global meridional overturning circulation. The role of nonaxisymmetric eddies is crucial, however, but the detailed mechanisms may differ between Venus, Titan, and other planets.

Titan's Complex Chemistry: Insights from the Lab

NASA Astrophysics Data System (ADS)

Horst, Sarah

2018-06-01

The Cassini-Huygens mission revealed Titan to be a complex world with physical processes reminiscent of other terrestrial planets, but chemistry that is unlike anywhere else in the Solar System. Titan's complex atmospheric chemistry converts N2 and CH4 into numerous, abundant organic molecules ranging from relatively simple hydrocarbons to ions with mass to charge ratios up to 10,000 amu/q. The molecules eventually settle to the surface where they can participate in and be modified by geological processes such as aeolian and fluvial erosion or undergo subsequent chemistry in Titan's lakes and seas or impact craters and potential cryovolcanic flows. From the processes leading to massive ion formation in the atmosphere to the behavior of saltating organic sands on the surface, laboratory experiments are playing a pivotal role in understanding Titan and expanding our understanding of planetary processes into new, exciting phase space.

In vitro dissolution of strontium titanate to estimate clearance rates in human lungs

NASA Astrophysics Data System (ADS)

Anderson, Jeri Lynn

At the In-Tank Precipitation facility (ITP) of the Savannah River Site, strontium and other radionuclides are removed from high-level radioactive waste and sent to the Defense Waste Processing Facility (DWPF). Strontium removal is accomplished by ion-exchange using monosodium titanate slurry which creates a form of strontium titanate with unknown solubility characteristics. In the case of accidental inhalation of a compound containing radioactive strontium, the ICRP, in Publication 66, recommends using default values for rates of absorption into body fluids at the lungs in the absence of reliable human or animal data. The default value depends on whether the absorption is considered to be fast, moderate, or slow (Type F, M, or S). Current dose assessment for an individual upon inadvertent exposure to airborne radioactive strontium assumes that all strontium compounds are Type F (soluble) or Type S (insoluble). Pure high-fired strontium titanate (SrTiOsb3) is considered Type S. The purpose of this project was to determine the solubility of strontium titanate in the form created at the ITP facility. An in vitro dissolution study was done with a precipitate simulant and with several types of strontium titanate and the results were compared. An in vivo study was also performed with high-fired SrTiOsb3 in rats. The data from both studies were used independently to assign the compounds to absorption type based on criteria specified in ICRP 71. Results of the in vitro studies showed that the DWPF simulant should be assigned to Type M and the strontium titanate should be assigned to Type S. It is possible the difference in the DWPF simulant is due to the other chemicals present. Results of the in vivo study verified that SrTiOsb3 should be assigned to Type S. Lung clearance data of SrTiOsb3 from rats showed that 85% cleared within the first 24 hours and the remaining 15% with a half-time of 130 days. The initial rapid clearance is attributed to deposition in airways as

Diurnal Variations of Titan's Surface Temperatures From Cassini -CIRS Observations

NASA Astrophysics Data System (ADS)

Cottini, Valeria; Nixon, Conor; Jennings, Don; Anderson, Carrie; Samuelson, Robert; Irwin, Patrick; Flasar, F. Michael

The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 m (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the in-strument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature pro-file by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). The application of our methodology over wide areas has increased the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. In particular we had the chance to look for diurnal variations in surface temperature around the equator: a trend with slowly increasing temperature toward the late afternoon reveals that diurnal temperature changes are present on Titan surface. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp

S-net project: Construction of large scale seafloor observatory network for tsunamis and earthquakes in Japan

NASA Astrophysics Data System (ADS)

Mochizuki, M.; Kanazawa, T.; Uehira, K.; Shimbo, T.; Shiomi, K.; Kunugi, T.; Aoi, S.; Matsumoto, T.; Sekiguchi, S.; Yamamoto, N.; Takahashi, N.; Shinohara, M.; Yamada, T.

2016-12-01

National Research Institute for Earth Science and Disaster Resilience ( NIED ) has launched the project of constructing an observatory network for tsunamis and earthquakes on the seafloor. The observatory network was named "S-net, Seafloor Observation Network for Earthquakes and Tsunamis along the Japan Trench". The S-net consists of 150 seafloor observatories which are connected in line with submarine optical cables. The total length of submarine optical cable is about 5,700 km. The S-net system extends along Kuril and Japan trenches around Japan islands from north to south covering the area between southeast off island of Hokkaido and off the Boso Peninsula, Chiba Prefecture. The project has been financially supported by MEXT Japan. An observatory package is 34cm in diameter and 226cm long. Each observatory equips two units of a high sensitive water-depth sensor as a tsunami meter and four sets of three-component seismometers. The water-depth sensor has measurement resolution of sub-centimeter level. Combination of multiple seismometers secures wide dynamic range and robustness of the observation that are needed for early earthquake warning. The S-net is composed of six segment networks that consists of about 25 observatories and 800-1,600km length submarine optical cable. Five of six segment networks except the one covering the outer rise area of the Japan Trench has been already installed. The data from the observatories on those five segment networks are being transferred to the data center at NIED on a real-time basis, and then verification of data integrity are being carried out at the present moment. Installation of the last segment network of the S-net, that is, the outer rise one is scheduled to be finished within FY2016. Full-scale operation of the S-net will start at FY2017. We will report construction and operation of the S-net submarine cable system as well as the outline of the obtained data in this presentation.

Advances in Architectural Elements For Future Missions to Titan

NASA Astrophysics Data System (ADS)

Reh, Kim; Coustenis, Athena; Lunine, Jonathan; Matson, Dennis; Lebreton, Jean-Pierre; Vargas, Andre; Beauchamp, Pat; Spilker, Tom; Strange, Nathan; Elliott, John

2010-05-01

The future exploration of Titan is of high priority for the solar system exploration community as recommended by the 2003 National Research Council (NRC) Decadal Survey [1] and ESA's Cosmic Vision Program themes. Recent Cassini-Huygens discoveries continue to emphasize that Titan is a complex world with very many Earth-like features. Titan has a dense, nitrogen atmosphere, an active climate and meteorological cycles where conditions are such that the working fluid, methane, plays the role that water does on Earth. Titan's surface, with lakes and seas, broad river valleys, sand dunes and mountains was formed by processes like those that have shaped the Earth. Supporting this panoply of Earth-like processes is an ice crust that floats atop what might be a liquid water ocean. Furthermore, Titan is rich in very many different organic compounds—more so than any place in the solar system, except Earth. The Titan Saturn System Mission (TSSM) concept that followed the 2007 TandEM ESA CV proposal [2] and the 2007 Titan Explorer NASA Flagship study [3], was examined [4,5] and prioritized by NASA and ESA in February 2009 as a mission to follow the Europa Jupiter System Mission. The TSSM study, like others before it, again concluded that an orbiter, a montgolfiere hot-air balloon and a surface package (e.g. lake lander, Geosaucer (instrumented heat shield), …) are very high priority elements for any future mission to Titan. Such missions could be conceived as Flagship/Cosmic Vision L-Class or as individual smaller missions that could possibly fit into NASA New Frontiers or ESA Cosmic Vision M-Class budgets. As a result of a multitude of Titan mission studies, a clear blueprint has been laid out for the work needed to reduce the risks inherent in such missions and the areas where advances would be beneficial for elements critical to future Titan missions have been identified. The purpose of this paper is to provide a brief overview of the flagship mission architecture and

Near-infrared study of Titan's resolved disk in spectro-imaging with CFHT/OASIS

NASA Astrophysics Data System (ADS)

Hirtzig, M.; Coustenis, A.; Lai, O.; Emsellem, E.; Pecontal-Rousset, A.; Rannou, P.; Negrão, A.; Schmitt, B.

2005-04-01

We present observations of Titan taken on November 17, 2000, with the near-infrared spectro-imaging system OASIS, mounted downstream of the CFHT/PUEO adaptive optics system. We have spatially resolved Titan's disk at Greatest Eastern Elongation. Our spectra cover the 0.86- 1.02μm range with a spectral resolution of 1800. By studying Titan at these wavelengths, we have recovered several pieces of information on the vertical and latitudinal structure of the atmosphere and surface of the satellite. The observing conditions were sufficiently good (AO-corrected seeing of 0.34") so as to allow us to separate the disk into 7 independent elements. From the flux contained in the 0.890μm methane band, we find that at higher altitudes on Titan, the North-South asymmetry is undergoing changes with respect to previous years when the South was much brighter than the North. This asymmetry still prevails in the troposphere, but at higher levels the well-known "Titan smile" - previously reported - disappears. We believe that we even have evidence for a reversal. The year 2000 may then represent the beginning of a seasonal change in Titan's haze distribution in the near-infrared, something which has been confirmed since but was not visible in the previous years. By comparing regions on Titan's disk with similar surface and stratospheric characteristics, we find an differences in the latitudinal distribution of the aerosol content in the intermediate altitude levels. Reflectivity measurements derived in the 0.94μm window (and hence pertaining to the surface conditions) show that the equatorial regions of the leading side are brighter than the surrounding areas, due to the presence of the large bright zone observed since 1994. Given our spatial resolution, we find this region to be 6% brighter than northern latitudes, 7% brighter than the South pole and in total we have a contrast of 9% between the darker and the brighter areas distinguishable on our images. The 0.94μm methane

Titan and Callisto

NASA Image and Video Library

2011-04-08

These images compare surface features observed by NASA Cassini spacecraft at the Xanadu region on Saturn moon Titan left, and features observed by NASA Galileo spacecraft on Jupiter cratered moon Callisto right.

How Does Titan Retain a Finite Orbital Eccentricity?

NASA Technical Reports Server (NTRS)

Bills, Bruce G.; Nimmo, Francis

2004-01-01

There is appreciable evidence for a significant hydrocarbon ocean on the surface of Titan. However, it has long been appreciated that tidal dissipation within a putative hydrocarbon ocean on Titan easily yields an orbital eccentricity damping time e which is short compared to the age of the solar system. Unless Titan s present eccentricity (e = 0.0288) were acquired recently, it requires that either: the ocean has a configuration which limits dissipation, or some mechanism exists which effectively maintains the eccentricity against dissipative damping. We argue for the latter. Specifically, the proximity of Jupiter and Saturn to a 5:2 mean motion resonance may provide a sufficient excitation source, and thereby effectively remove dynamical constraints on the dissipation and configuration of the Titan ocean.

Saturn's Magnetospheric Plasma Flow Encountered by Titan

NASA Astrophysics Data System (ADS)

Sillanpää, I.

2017-09-01

Titan has been a major target of the ending Cassini mission to Saturn. 126 flybys have sampled, measured and observed a variety of Titan's features and processes from the surface features to atmospheric composition and upper atmospheric processes. Titan's interaction with the magnetospheric plasma flow it is mostly embedded in is highly dependent on the characteristics of the ambient plasma. The density, velocity and even the composition of the plasma flow can have great variance from flyby to flyby. Our purpose is the present the plasma flow conditions for all over 70 flybys of which we have Cassini Plasma Spectrometer (CAPS) measurements.

Titanate-based adsorbents for radioactive ions entrapment from water.

PubMed

Yang, Dongjiang; Liu, Hongwei; Zheng, Zhanfeng; Sarina, Sarina; Zhu, Huaiyong

2013-03-21

This feature article reviews some titanate-based adsorbents for the removal of radioactive wastes (cations and anions) from water. At the beginning, we discuss the development of the conventional ion-exchangeable titanate powders for the entrapment of radioactive cations, such as crystalline silicotitanate (CST), monosodium titanate (MST), peroxotitanate (PT). Then, we specially emphasize the recent progress in the uptake of radioactive ions by one-dimensional (1D) sodium titanate nanofibers and nanotubes, which includes the synthesis and phase transformation of the 1D nanomaterials, adsorption ability (capacity, selectivity, kinetics, etc.) of radioactive cations and anions, and the structural evolution during the adsorption process.

Titan's lower troposphere: thermal structure and dynamics

NASA Astrophysics Data System (ADS)

Charnay, B.; Lebonnois, S.

2011-12-01

A new climate model for Titan's atmosphere has been developed, using the physics of the IPSL Titan 2-dimensional climate model with the current version of the LMDZ General Circulation Model's dynamical core. The GCM covers altitudes from the surface to 500 km with the diurnal cycle and the gravitational tides included. 1. Boundary layer and thermal structure The HASI profile of potential temperature shows a layer at 300 m, an other at 800 m and a slope change at 2 km ([5],[2]). Dune spacing on Titan is consistent with a 2-3 km boundary layer ([3]). We have reproduced this profile (see figure) and interpreted the layer at 300 m as a convective boundary layer, the layer at 800 m is a residual layer corresponding to the maximum diurnal vertical extension of the PBL. We interpret the slope change at 2 km as produced by the seasonal displacement of the ITCZ. This layer traps the circulation in the first two km and is responsible of the dune spacing. Finally we interpret the fog discovered in summer polar region ([1]) has clouds produced by the diurnal cycle of the PBL (as fair weather cumulus on Earth). 2. Surface winds 2.1 Effect of gravitational and thermal tides We analysed tropospheric winds and the influence of both the thermal and the gravitational tides. The impact of gravitational tides on the circulation is extremely small. Thermal tides have a visible effect, though quite tenuous. 2.2 Effect of topography We produced topography maps derived from spherical harmonic interpolation ([6]) on the reference ellipsoid ([4]). Surface temperatures at high altitude appear higher that the ambient air. Vertical air movements produce anabatic winds developing on smooth and long slopes. This could be one of the main causes controlling the direction of surface winds and the direction of dunes. References [1] Brown et al.: Discovery of fog at the south pole of Titan, Astrophys. J. 706 (2009), pp. L110-L113 [2] Griffith et al.: Titan's Tropical Storms in an Evolving Atmosphere

Recent Trend of New Type Power Delivery System and its Demonstrative Project in Japan

NASA Astrophysics Data System (ADS)

Morozumi, Satoshi; Nara, Koichi

Recently many such distributed generating systems as co-generation, photovoltaic, wind, fuel cells etc. are introduced into power distribution system, and the power system must cope with the situation with distributed generators. Moreover, such industries as IT request reliable and high quality power to preserve their businesses, and some other electric energy based industries request less reliable but cheaper electricity. From these backgrounds, several new type power delivery systems are emerging where lots of distributed generators (DGs) can be connected and many benefits offered by DGs can be realized without affecting the existing power system. They are referred to various names. In U.S.A., Microgrid, Power Park and Virtual Utilities, etc. are proposed. In Europe, DISPOWER or Smart Grid is under developing. In Japan, FRIENDS and Demand Area Network System etc. are proposed and tested in real sites. In this paper, first, general concepts of such new type power delivery systems and new businesses expected to be created by using DGs are introduced. Then, recent research activities in this area in Japan are introduced so as to stimulate new business opportunities. In the later part of this paper, related NEDO's demonstrative projects are introduced. NEDO is the largest public R&D management organization and promoting several projects regarding grid connecting issues on the power system. Those projects were planned to solve several problems on the power system where distributed renewable energy resources are installed.

Titan Cell Production Enhances the Virulence of Cryptococcus neoformans

PubMed Central

Crabtree, Juliet N.; Okagaki, Laura H.; Wiesner, Darin L.; Strain, Anna K.; Nielsen, Judith N.

2012-01-01

Infection with Cryptococcus neoformans begins when desiccated yeast cells or spores are inhaled and lodge in the alveoli of the lungs. A subset of cryptococcal cells in the lungs differentiate into enlarged cells, referred to as titan cells. Titan cells can be as large as 50 to 100 μm in diameter and exhibit a number of features that may affect interactions with host immune defenses. To characterize the effect of titan cell formation on the host-pathogen interaction, we utilized a previously described C. neoformans mutant, the gpr4Δ gpr5Δ mutant, which has minimal titan cell production in vivo. The gpr4Δ gpr5Δ mutant strain had attenuated virulence, a lower CFU, and reduced dissemination compared to the wild-type strain. Titan cell production by the wild-type strain also resulted in increased eosinophil accumulation and decreased phagocytosis in the lungs compared to those with the gpr4Δ gpr5Δ mutant strain. Phagocytosed cryptococcal cells exhibited less viability than nonphagocytosed cells, which potentially explains the reduced cell survival and overall attenuation of virulence in the absence of titan cells. These data show that titan cell formation is a novel virulence factor in C. neoformans that promotes establishment of the initial pulmonary infection and plays a key role in disease progression. PMID:22890995

Titan cell production enhances the virulence of Cryptococcus neoformans.

PubMed

Crabtree, Juliet N; Okagaki, Laura H; Wiesner, Darin L; Strain, Anna K; Nielsen, Judith N; Nielsen, Kirsten

2012-11-01

Infection with Cryptococcus neoformans begins when desiccated yeast cells or spores are inhaled and lodge in the alveoli of the lungs. A subset of cryptococcal cells in the lungs differentiate into enlarged cells, referred to as titan cells. Titan cells can be as large as 50 to 100 μm in diameter and exhibit a number of features that may affect interactions with host immune defenses. To characterize the effect of titan cell formation on the host-pathogen interaction, we utilized a previously described C. neoformans mutant, the gpr4Δ gpr5Δ mutant, which has minimal titan cell production in vivo. The gpr4Δ gpr5Δ mutant strain had attenuated virulence, a lower CFU, and reduced dissemination compared to the wild-type strain. Titan cell production by the wild-type strain also resulted in increased eosinophil accumulation and decreased phagocytosis in the lungs compared to those with the gpr4Δ gpr5Δ mutant strain. Phagocytosed cryptococcal cells exhibited less viability than nonphagocytosed cells, which potentially explains the reduced cell survival and overall attenuation of virulence in the absence of titan cells. These data show that titan cell formation is a novel virulence factor in C. neoformans that promotes establishment of the initial pulmonary infection and plays a key role in disease progression.

ARPS Enabled Titan Rover Concept with Inflatable Wheels

NASA Technical Reports Server (NTRS)

Balint, Tibor S.; Schriener, Timothy M.; Shirley, James H.

2006-01-01

The Decadal Survey identified Titan as one of the top priority science destinations in the large moons category, while NASA's proposed Design Reference Mission Set ranked a Titan in-situ explorer second, after a recommended Europa Geophysical Observer mission. This paper discusses a Titan rover concept, enabled by a single advanced Radioisotope Power System that could provide about 110We (BOL). The concept targets the smaller Flagship or potentially the New Frontiers mission class. This MSL class rover would traverse on four 1.5 m diameter inflatable wheels during its 3 years mission duration and would use as much design and flight heritage as possible to reduce mission cost. Direct to Earth communication would remove the need for a relay orbiter. Details on the strawman instrument payload, and rover subsystems are given for this science driven mission concept. In addition, power system trades between Advanced RTG, TPV, and Advanced Stirling and Brayton Radioisotope Power Systems (RPS) are outlined. While many possible approaches exist for Titan in-situ exploration, the Titan rover concept presented here could provide a scientifically interesting and programmatically affordable solution.

High definition systems in Japan

NASA Technical Reports Server (NTRS)

Elkus, Richard J., Jr.; Cohen, Robert B.; Dayton, Birney D.; Messerschmitt, David G.; Schreiber, William F.; Tannas, Lawrence E., Jr.; Shelton, Duane

1991-01-01

The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems.

77 FR 59690 - Titan Resources International, Corp.; Order of Suspension of Trading

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-28

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Titan Resources International, Corp.; Order of... a lack of current and accurate information concerning the securities of Titan Resources International, Corp. (``Titan''). Titan is a Wyoming corporation purportedly based in Ontario, Canada. Questions...

Titan's seasonal weather patterns, associated surface modification, and geological implications

NASA Astrophysics Data System (ADS)

Turtle, E. P.; Perry, J. E.; Barnes, J. W.; McEwen, A. S.; Barbara, J. M.; Del Genio, A. D.; Hayes, A. G.; West, R. A.; Lorenz, R. D.; Schaller, E. L.; Lunine, J. I.; Ray, T. L.; Lopes, R. M. C.; Stofan, E. R.

2013-09-01

Model predictions [e.g., 1-3] and observations [e.g., 4,5] illustrate changes in Titan's weather patterns related to the seasons (Fig. 1). In two cases, surface changes were documented following large cloud outbursts (Figs. 2, 3): the first in Arrakis Planitia at high southern latitudes in Fall 2004, during Titan's late southern summer [6]; and the second at lows southern latitudes in Concordia and Hetpet Regiones, Yalaing Terra (Fig. 3), and Adiri, in Fall 2010, just over a year after Titan's northern vernal equinox [4, 7, 8]. Not only do these storms demonstrate Titan's atmospheric conditions and processes, they also have important implications for Titan's surface process, its methane cycle, and its geologic history.

Energetic neutral atom emissions from Titan interaction with Saturn's magnetosphere.

PubMed

Mitchell, D G; Brandt, P C; Roelof, E C; Dandouras, J; Krimigis, S M; Mauk, B H

2005-05-13

The Cassini Magnetospheric Imaging Instrument (MIMI) observed the interaction of Saturn's largest moon, Titan, with Saturn's magnetosphere during two close flybys of Titan on 26 October and 13 December 2004. The MIMI Ion and Neutral Camera (INCA) continuously imaged the energetic neutral atoms (ENAs) generated by charge exchange reactions between the energetic, singly ionized trapped magnetospheric ions and the outer atmosphere, or exosphere, of Titan. The images reveal a halo of variable ENA emission about Titan's nearly collisionless outer atmosphere that fades at larger distances as the exospheric density decays exponentially. The altitude of the emissions varies, and they are not symmetrical about the moon, reflecting the complexity of the interactions between Titan's upper atmosphere and Saturn's space environment.

The vertical profile of winds on Titan.

PubMed

Bird, M K; Allison, M; Asmar, S W; Atkinson, D H; Avruch, I M; Dutta-Roy, R; Dzierma, Y; Edenhofer, P; Folkner, W M; Gurvits, L I; Johnston, D V; Plettemeier, D; Pogrebenko, S V; Preston, R A; Tyler, G L

2005-12-08

One of Titan's most intriguing attributes is its copious but featureless atmosphere. The Voyager 1 fly-by and occultation in 1980 provided the first radial survey of Titan's atmospheric pressure and temperature and evidence for the presence of strong zonal winds. It was realized that the motion of an atmospheric probe could be used to study the winds, which led to the inclusion of the Doppler Wind Experiment on the Huygens probe. Here we report a high resolution vertical profile of Titan's winds, with an estimated accuracy of better than 1 m s(-1). The zonal winds were prograde during most of the atmospheric descent, providing in situ confirmation of superrotation on Titan. A layer with surprisingly slow wind, where the velocity decreased to near zero, was detected at altitudes between 60 and 100 km. Generally weak winds (approximately 1 m s(-1)) were seen in the lowest 5 km of descent.

Low-Latitude Ethane Rain on Titan

NASA Technical Reports Server (NTRS)

Dalba, Paul A.; Buratti, Bonnie J.; Brown, R. H.; Barnes, J. W.; Baines, K. H.; Sotin, C.; Clark, R. N.; Lawrence, K. J.; Nicholson, P. D.

2012-01-01

Cassini ISS observed multiple widespread changes in surface brightness in Titan's equatorial regions over the past three years. These brightness variations are attributed to rainfall from cloud systems that appear to form seasonally. Determining the composition of this rainfall is an important step in understanding the "methanological" cycle on Titan. I use data from Cassini VIMS to complete a spectroscopic investigation of multiple rain-wetted areas. I compute "before-and-after" spectral ratios of any areas that show either deposition or evaporation of rain. By comparing these spectral ratios to a model of liquid ethane, I find that the rain is most likely composed of liquid ethane. The spectrum of liquid ethane contains multiple absorption features that fall within the 2-micron and 5-micron spectral windows in Titan's atmosphere. I show that these features are visible in the spectra taken of Titan's surface and that they are characteristically different than those in the spectrum of liquid methane. Furthermore, just as ISS saw the surface brightness reverting to its original state after a period of time, I show that VIMS observations of later flybys show the surface composition in different stages of returning to its initial form.

The Titan Haze Simulation Experiment: Latest Laboratory Results and Dedicated Plasma Chemistry Model

NASA Astrophysics Data System (ADS)

Sciamma-O'Brien, Ella; Raymond, Alexander; Mazur, Eric; Salama, Farid

2018-06-01

Here, we present the latest results on the gas and solid phase analyses in the Titan Haze Simulation (THS) experiment. The THS experiment, developed at NASA Ames’ COSmIC facility is a unique experimental platform that allows us to simulate Titan’s complex atmospheric chemistry at Titan-like temperature (200 K) by cooling down N2-CH4-based mixtures in a supersonic expansion before inducing the chemistry by plasma.Gas phase: The residence time of the jet-accelerated gas in the active plasma region is less than 4 µs, which results in a truncated chemistry enabling us to control how far in the chain of reactions the chemistry is processing. By adding heavier molecules in the initial gas mixture, it is then possible to study the first and intermediate steps of Titan’s atmospheric chemistry as well as specific chemical pathways, as demonstrated by mass spectrometry and comparison to Cassini CAPS data [1]. A new model was recently developed to simulate the plasma chemistry in the THS. Calculated mass spectra produced by this model are in good agreement with the experimental THS mass spectra, confirming that the short residence time in the plasma cavity limits the growth of larger species [2].Solid phase: Scanning electron microscopy and infrared spectroscopy have been used to investigate the effect of the initial gas mixture on the morphology of the THS Titan aerosol analogs as well as on the level and nature of the nitrogen incorporation into these aerosols. A comparison to Cassini VIMS observational data has shown that the THS aerosols produced in simpler mixtures, i.e., that contain more nitrogen and where the N-incorporation is in isocyanide-type molecules instead of nitriles, are more representative of Titan’s aerosols [3]. In addition, a new optical constant facility has been developed at NASA Ames that allows us to determine the complex refractive indices of THS Titan aerosol analogs from NIR to FIR (0.76-222 cm-1). The facility and preliminary results

Numerical modelling of sedimentary structures in rivers on Titan and Earth

NASA Astrophysics Data System (ADS)

Misiura, Katarzyna; Czechowski, Leszek

2016-04-01

On Titan surface we can expect a few different geomorphological forms, e.g. fluvial valley and river channels. In our research we use numerical model of the river to determine the limits of different fluvial parameters that play important roles in evolution of the rivers on Titan and on Earth. We have found that transport of sediments as suspended load is the main way of transport for Titan. We also determined the range of the river's parameters for which braided river is developed rather than meandering river. 2. Introduction Titan is a very special body in the Solar System. It is the only moon that has dense atmosphere and flowing liquid on its surface. The Cassini-Huygens mission has found on Titan meandering rivers, and indicated processes of erosion, transport of solid material and its sedimentation. This work is aimed to investigate the similarity and differences between these processes on Titan and the Earth. 3. Numerical model The dynamical analysis of the considered rivers is performed using the package CCHE modified for the specific conditions on Titan. The package is based on the Navier-Stokes equations for depth-integrated two dimensional, turbulent flow and three dimensional convection-diffusion equation of sediment transport. For more information about equations see [1]. 4. Parameters of the model We considered our model for a few different parameters of liquid and material transported by a river. For Titan we consider liquid corresponding to a Titan's rain (75% methane, 25% nitrogen), for Earth, of course, the water. Material transported in rivers on Titan is water ice, for Earth - quartz. Other parameters of our model are: inflow discharge, outflow level, grain size of sediments etc. For every calculation performed for Titan's river similar calculations are performed for terrestrial ones. 5. Results and Conclusions The results of our simulation show the differences in behaviour of the flow and of sedimentation on Titan and on the Earth. Our

Methane on Titan: Photochemical-Meteorological-Hydrogeochemical Cycle

NASA Astrophysics Data System (ADS)

Atreya, S. K.; Niemann, H. B.; Owen, T. C.; Adams, E. Y.; Demick, J. E.; GCMS Team

2005-08-01

Photochemically driven destruction of methane in Titan's stratosphere leads to irreversible conversion to heavier hydrocarbons (1). The latter would largely condense out of the atmosphere (2). In the absence of recycling, Titan's methane would thus be destroyed in 10-100 million years (1). However, methane is key to the maintenance of Titan's nitrogen atmosphere. Without warming provided by CH4-generated hydrocarbon hazes in the stratosphere and pressure induced opacity in the infrared, particularly by H2-N2 and CH4-N2 collisions in the troposphere, the atmosphere would gradually diminish to tens of millibar pressure (3). Thus, the source-sink cycle of methane is crucial to the evolutionary history of Titan and its atmosphere. The GCMS measurements show that a ``methalogical" cycle with surface evaporation, cloud formation, followed by precipitation (rain) of methane exists. However, this ``closed" cycle does not recycle methane lost to heavy hydrocarbons. A source is required. Unlike the deep, hot, H2-rich interiors of the giant planets, Titan's interior is ill suited for thermochemical conversion of hydrocarbons back to methane. Instead we propose that serpentinization is an effective process for producing methane in Titan's interior (4). Hydration of ultramafic silicates, followed by reaction between the released H2 gas and CO2 or carbon grains can produce large quantities of CH4 at relatively mild (40-90oC) temperatures. Such thermal conditions are believed to exist below the purported water-ammonia ocean (5). Storage of methane produced via serpentinization can occur in form of clathrates. Evidence of outgassing from Titan's interior is provided by GCMS (6) and VIMS (7) data. (1) Wilson, Atreya, JGR 109, E06002, doi:10.1029/2003JE002181, 2004. (2) Wilson, Atreya, PSS 51, 1017, 2003. (3) Lorenz etal. Science 275, 642, 1997. (4) Owen etal. Phys. Uspekhi, in press. (5) Grasset, Pargamin, PSS 53, 371, 2005. (6) Niemann etal., Submitted to Nature, 2005. (7) Sotin

Photometric properties of Titan's surface from Cassini VIMS: Relevance to titan's hemispherical albedo dichotomy and surface stability

USGS Publications Warehouse

Nelson, R.M.; Brown, R.H.; Hapke, B.W.; Smythe, W.D.; Kamp, L.; Boryta, M.D.; Leader, F.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Combes, M.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe

2006-01-01

The Visual and Infrared Mapping Spectrometer (VIMS) instrument on the Cassini Saturn Orbiter returned spectral imaging data as the spacecraft undertook six close encounters with Titan beginning 7 July, 2004. Three of these flybys each produced overlapping coverage of two distinct regions of Titan's surface. Twenty-four points were selected on approximately opposite hemispheres to serve as photometric controls. Six points were selected in each of four reflectance classes. On one hemisphere each control point was observed at three distinct phase angles. From the derived phase coefficients, preliminary normal reflectances were derived for each reflectance class. The normal reflectance of Titan's surface units at 2.0178 ??m ranged from 0.079 to 0.185 for the most absorbing to the most reflective units assuming no contribution from absorbing haze. When a modest haze contribution of ??=0.1 is considered these numbers increase to 0.089-0.215. We find that the lowest three reflectance classes have comparable normal reflectance on either hemisphere. However, for the highest brightness class the normal reflectance is higher on the hemisphere encompassing longitude 14-65?? compared to the same high brightness class for the hemisphere encompassing 122-156?? longitude. We conclude that an albedo dichotomy observed in continental sized units on Titan is due not only to one unit having more areal coverage of reflective material than the other but the material on the brighter unit is intrinsically more reflective than the most reflective material on the other unit. This suggests that surface renewal processes are more widespread on Titan's more reflective units than on its less reflective units. We note that one of our photometric control points has increased in reflectance by 12% relative to the surrounding terrain from July of 2004 to April and May of 2005. Possible causes of this effect include atmospheric processes such as ground fog or orographic clouds; the suggestion of

Introducing the Japan Unified HIgh-Resolution Relocated Catalog for Earthquakes (JUICE) Project

NASA Astrophysics Data System (ADS)

Yano, T. E.; Takeda, T.; Shiomi, K.

2013-12-01

To understand the tectonic processes, seismogenic zones, and active fault evaluations, the precise location of earthquake hypocenters is necessary. Routinely determined hypocenters typically have uncertainties that can make seismically active areas appear more diffuse. These uncertainties influence the interpretation of what are active faults. Objective of this Japan Unified HIgh-resolution Relocated Catalog for Earthquakes (JUICE) project is to create a high-resolution earthquake relocated catalog for all of Japan. To initiate the project, we relocate hypocenters around Kanto-Tokai region. The network geometry, available phases, arrival-time reading accuracy, and knowledge of crustal structure control the accuracy of absolute hypocenter locations (Pavlis, 1986; Gomberg et al., 1990). We take advantage of having an excellent network operated by NIED Hi-net team. We use the high-quality data from this network for events from 2001 to the present. To initiate the JUICE project, we utilize more than 5,500,000 and 5,300,000 P and S phase arrival-time readings (catalog data) and waveforms for about 120,000 events between M0 and M6.5 from 2001 through 2012 in the Kanto and Tokai region. To reduce uncertainties, we apply the double-difference algorithm (hypoDD) by Waldhauser and Ellsworth (2000) to the data. To obtain the travel time differences for the pairs of earthquakes, we cross correlate the seismograms at the stations, which produces another data set -- cross-correlation data. In addition to the catalog phase data, we add 800,000 and 1,000,000 of P and S phase cross-correlations that are used to relocate hypocenters. We use Hi-net routine velocity structure (Ukawa et al., 1984) to estimate theoretical differential travel times. The newly relocated hypocenters show tighter clusters and lineaments compared to the routinely generated hypocenters. Figure 1 (a) shows the hypocenters in the Shizuoka region before relocation and (b) shows the hypocenters after relocation

Energy Budgets of the Giant Planets and Titan

NASA Technical Reports Server (NTRS)

Liming, Li; Smith, Mark A.; Conrath, Barney J.; Conrath, Peter J.; Simon-Miller, Amy A.; Baines, Kevin H.; West, Robert A.; Achterberg, Richard K.; Orton, Glenn S.; Santiago, Perez-Hoyos;

Canadian-US Demonstration Project Towards an International ...

EPA Pesticide Factsheets

Bellingham Bay will provide the test case for an international nitrogen (N) management system for North America. Spanning a portion of the western interface of the U.S. and Canada, the region supports intensive agriculture, freshwater and estuarine fisheries, diverse wildlife, cities and towns, and to the east, North Cascades National Park that is protected by the US Wilderness Acts. Using abundant data and model activities from a well-established scientific community, our project seeks to create knowledge, build regional capacity, and forge collaborations toward creation of regional N management solutions that protect or restore ecosystems and human health affected by excess reactive N while maintaining a vibrant agricultural community. As an outgrowth of the International Nitrogen Initiative's North American Nitrogen Committee, US and Canadian scientists will collaborate on a demonstration project centered on Bellingham Bay on the US-Canada border. This location presents a good opportunity for this international collaborative effort because of abundant scientific data and numerous connections to engaged scientists and stakeholders. There are other well-studied areas in the US but this presents an opportunity to develop new international collaboration in an area with nitrogen-sensitive terrestrial, groundwater, rivers and coastal systems. There is a tremendous opportunity to collaborate on nitrogen management methods across the U.S. and Canada, as well as with

Cryovolcanism on Titan

NASA Astrophysics Data System (ADS)

Mitri, G.; Showman, A. P.; Lunine, J. I.; Lopes, R. M.

2008-12-01

Remote sensing observations yield evidence for cryovolcanism on Titan, and evolutionary models support (but do not require) the presence of an ammonia-water subsurface ocean. The impetus for invoking ammonia as a constituent in an internal ocean and cryovolcanic magma comes from two factors. First, ammonia-water liquid has a lower freezing temperature than pure liquid water, enabling cryovolcanism under the low- temperature conditions prevalent in the outer Solar System. Second, pure water is negatively buoyant with respect to pure water ice, which discourages eruption from the subsurface ocean to the surface. In contrast, the addition of ammonia to the water decreases its density, hence lessening this problem of negative buoyancy. A marginally positive buoyant ammonia-water mixture might allow effusive eruptions from a subsurface ocean. If the subsurface ocean were positively buoyant, all the ammonia would have been erupted very early in Titan's history. Contrary to this scenario, Cassini-Huygens has so far observed neither a global abundance nor a complete dearth of cryovolcanic features. Further, an ancient cryovolcanic epoch cannot explain the relative youth of Titan's surface. Crucial to invoking ammonia-water resurfacing as the source of the apparently recent geological activity is not how to make ammonia-water volcanism work (because the near neutral buoyancy of the ammonia-water mixture encourages an explanation), but rather how to prevent eruption from occurring so easily that cryovolcanic activity is over early on. Although cryovolcanism by ammonia-water has been proposed as a resurfacing process on Titan, few models have specifically dealt with the problem of how to transport ammonia-water liquid onto the surface. We proposed a model of cryovolcanism that involve cracking at the base of the ice shell and formation of ammonia-water pockets in the ice. While the ammonia-water pockets cannot easily become neutral buoyant and promote effusive eruptions

Titan's missing ethane: From the atmosphere to the subsurface

NASA Astrophysics Data System (ADS)

Gilliam, Ashley E.; Lerman, Abraham

2016-09-01

The second most abundant component of the present-day Titan atmosphere, methane (CH4), is known to undergo photolytic conversion to ethane (C2H6) that accumulates as a liquid on Titan's surface. Condensation temperature of ethane is higher than that of methane, so that ethane "rain" may be expected to occur before the liquefaction of methane. At present, the partial pressure of ethane in the atmosphere is 1E-5 bar, much lower than 1E-1 bar of CH4. Estimated 8.46E17 kg or 1.37E6 km3 of C2H6 have been produced on Titan since accretion. The Titan surface reservoirs of ethane are lakes and craters, of estimated volume of 50,000 km3 and 61,000 km3, respectively. As these are smaller than the total volume of liquid ethane produced in the course of Titan's history, the excess may be stored in the subsurface of the crust, made primarily of water ice. The minimum porosity of the crust needed to accommodate all the liquid ethane would be only 0.9% of the uppermost 2 km of the crust. The occurrence of CH4 and liquid C2H6 on Titan has led to much speculation on the possibility of life on that satellite. The aggregation of organic molecules in a "primordial soup or bullion" depends in part on the viscosity of the medium, diffusivity of organic molecules in it, and rates of polymerization reactions. The temperatures on Titan, much lower than on primordial Earth, are less favorable to the "Second Coming of life" on Titan.

A Single Deformed Bow Shock for Titan-Saturn System

NASA Astrophysics Data System (ADS)

Sulaiman, A. H.; Omidi, N.; Kurth, W. S.; Madanian, H.; Cravens, T.; Sergis, N.; Dougherty, M. K.; Edberg, N. J. T.

2017-12-01

During periods of high solar wind pressure, Saturn's bow shock is pushed inside Titan's orbit exposing the moon and its ionosphere to the supersonic solar wind. The Cassini spacecraft's T96 encounter with Titan occurred during such a period and is the subject of this presentation. The observations during this encounter show evidence for the presence of outbound and inbound shock crossings associated with Saturn and Titan. They also reveal the presence of two foreshocks: one between the outbound Kronian and inbound Titan bow shocks (foreshock-1) and the other between the outbound Titan and inbound Kronian bow shocks (foreshock-2). Using electromagnetic hybrid (kinetic ions, fluid electrons) simulations and Cassini observations we show that the origin of foreshock-1 is tied to the formation of a single deformed bow shock for the Titan-Saturn system. We also report for the first time, the observations of spontaneous hot flow anomalies (SHFAs) in foreshock-1 making Saturn the fourth planet this phenomenon has been observed and indicating its universal nature. The results of hybrid simulations also show the generation of oblique fast magnetosonic waves upstream of the outbound Titan bow shock in agreement with the observations of large amplitude magnetosonic pulsations in foreshock-2. The formation of a single deformed bow shock results in unique foreshock-bow shock or foreshock-foreshock geometries. For example, the presence of Saturn's foreshock upstream of Titan's quasi-perpendicular bow shock result in ion acceleration through a combination of shock drift and Fermi processes. We also discuss the implications of a single deformed bow shock for Saturn's magnetopause and magnetosphere.

DISCOVERY OF FOG AT THE SOUTH POLE OF TITAN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, M. E.; Smith, A. L.; Chen, C.

2009-11-20

While Saturn's moon Titan appears to support an active methane hydrological cycle, no direct evidence for surface-atmosphere exchange has yet appeared. The indirect evidence, while compelling, could be misleading. It is possible, for example, that the identified lake features could be filled with ethane, an involatile long-term residue of atmospheric photolysis; the apparent stream and channel features could be ancient remnants of a previous climate; and the tropospheric methane clouds, while frequent, could cause no rain to reach the surface. We report here the detection of fog at the south pole of Titan during late summer using observations from themore » VIMS instrument on board the Cassini spacecraft. While terrestrial fog can form from a variety of causes, most of these processes are inoperable on Titan. Fog on Titan can only be caused by evaporation of nearly pure liquid methane; the detection of fog provides the first direct link between surface and atmospheric methane. Based on the detections presented here, liquid methane appears widespread at the south pole of Titan in late southern summer, and the hydrological cycle on Titan is currently active.« less

Equatorial Titan Clouds

NASA Image and Video Library

2011-03-17

NASA Cassini spacecraft chronicles the change of seasons as it captures clouds concentrated near the equator of Saturn largest moon, Titan. Methane clouds in the troposphere, the lowest part of the atmosphere, appear white here.

Northern Summer on Titan

NASA Image and Video Library

2017-06-14

NASA's Cassini spacecraft sees bright methane clouds drifting in the summer skies of Saturn's moon Titan, along with dark hydrocarbon lakes and seas clustered around the north pole. Compared to earlier in Cassini's mission, most of the surface in the moon's northern high latitudes is now illuminated by the sun. The image was taken with the Cassini spacecraft narrow-angle camera on June 9, 2017, using a spectral filter that preferentially admits wavelengths of near-infrared light centered at 938 nanometers. Cassini obtained the view at a distance of about 315,000 miles (507,000 kilometers) from Titan. https://photojournal.jpl.nasa.gov/catalog/PIA21615

Expansion of Titan atmosphere

NASA Astrophysics Data System (ADS)

Salem, S.; Moslem, W. M.; Radi, A.

2017-05-01

Self-similar plasma expansion approach is used to solve a plasma model based on the losing phenomenon of Titan atmospheric composition. To this purpose, a set of hydrodynamic fluid equations describing a plasma consisting of two positive ions with different masses and isothermal electrons is used. With the aid of self-similar transformation, numerical solution of the fluid equations has been performed to examine the density, velocity, and potential profiles. The effects of different plasma parameters, i.e., density and temperature ratios, are studied on the expanding plasma profiles. The present investigation could be useful to recognize the ionized particles escaping from Titan atmosphere.

Titan brighter at twilight than in daylight

NASA Astrophysics Data System (ADS)

García Muñoz, A.; Lavvas, P.; West, R. A.

2017-04-01

Investigating the overall brightness of planets (and moons) provides insights into their envelopes and energy budgets 1-4 . Phase curves (a representation of the overall brightness versus the Sun-object-observer phase angle) for Titan have been published over a limited range of phase angles and spectral passbands 5,6 . Such information has been key to the study of the stratification, microphysics and aggregate nature of Titan's atmospheric haze 7,8 and has complemented the spatially resolved observations showing that the haze scatters efficiently in the forward direction 7,9 . Here, we present Cassini Imaging Science Subsystem whole-disk brightness measurements of Titan from ultraviolet to near-infrared wavelengths. The observations show that Titan's twilight (loosely defined as the view at phase angles ≳150°) outshines its daylight at various wavelengths. From the match between measurements and models, we show that at even larger phase angles, the back-illuminated moon will appear much brighter than when fully illuminated. This behaviour is unique in our Solar System to Titan and is caused by its extended atmosphere and the efficient forward scattering of sunlight by its atmospheric haze. We infer a solar energy deposition rate (for a solar constant of 14.9 W m-2) of (2.84 ± 0.11) × 1014 W, consistent to within one to two standard deviations with Titan's time-varying thermal emission from 2007 to 2013 10,11 . We propose that a forward scattering signature may also occur at large phase angles in the brightness of exoplanets with extended hazy atmospheres and that this signature has a valuable diagnostic potential for atmospheric characterization.

Neptune and Titan Observed with Keck Telescope Adaptive Optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Max, C.E.; Macintosh, B.A.; Gibbard, S.

2000-05-05

The authors report on observations taken during engineering science validation time using the new adaptive optics system at the 10-m Keck II Telescope. They observe Neptune and Titan at near-infrared wavelengths. These objects are ideal for adaptive optics imaging because they are bright and small, yet have many diffraction-limited resolution elements across their disks. In addition Neptune and Titan have prominent physical features, some of which change markedly with time. They have observed infrared-bright storms on Neptune, and very low-albedo surface regions on Titan, Saturn's largest moon, Spatial resolution on Neptune and Titan was 0.05-0.06 and 0.04-0.05 arc sec, respectively.

The identification of liquid ethane in Titan's Ontario Lacus

USGS Publications Warehouse

Brown, R.H.; Soderblom, L.A.; Soderblom, J.M.; Clark, R.N.; Jaumann, R.; Barnes, J.W.; Sotin, Christophe; Buratti, B.; Baines, K.H.; Nicholson, P.D.

2008-01-01

Titan was once thought to have global oceans of light hydrocarbons on its surface, but after 40 close flybys of Titan by the Cassini spacecraft, it has become clear that no such oceans exist. There are, however, features similar to terrestrial lakes and seas, and widespread evidence for fluvial erosion, presumably driven by precipitation of liquid methane from Titan's dense, nitrogen-dominated atmosphere. Here we report infrared spectroscopic data, obtained by the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft, that strongly indicate that ethane, probably in liquid solution with methane, nitrogen and other low-molecular-mass hydrocarbons, is contained within Titan's Ontario Lacus.

The greenhouse and antigreenhouse effects on Titan

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

1991-01-01

The parallels between the atmospheric thermal structure of the Saturnian satellite Titan and the hypothesized terrestrial greenhouse effect can serve as bases for the evaluation of competing greenhouse theories. Attention is presently drawn to the similarity between the roles of H2 and CH4 on Titan and CO2 and H2O on earth. Titan also has an antigreenhouse effect due to a high-altitude haze layer which absorbs at solar wavelengths, while remaining transparent in the thermal IR; if this haze layer were removed, the antigreenhouse effect would be greatly reduced, exacerbating the greenhouse effect and raising surface temperature by over 20 K.

Constraints on Titan rotation from Cassini radar

NASA Astrophysics Data System (ADS)

Bills, B. G.; Stiles, B. W.; Kirk, R. L.

2014-12-01

We give an update on efforts to model the rotation of Titan, subject to constraints from Cassini radar observations. The data we are currently using includes 670 tie-points, each of which is a pair of inertial positions of a single surface point, relative to the center of mass of Titan, and the corresponding pair of observation times. The positional accuracy is of order 1 km, in each Cartesian component. A reasonably good fit to the observations is obtained with a simple model which has a fixed spin pole and a rotation rate which is a sum of a constant value and a single sinusoidal oscillation. A better fit is obtained if we insist that Titan should behave as a synchronous rotator, in the dynamical sense of keeping its axis of least inertia oriented toward Saturn. At the level of accuracy required to fit the Cassini radar data, synchronous rotation is notably different than having a uniform rate of rotation. In this case, we need to model time variations in the orbital mean longitude, which is the longitude of periapse, plus the mean anomaly. That angle varies on a wide range of times scales, including Titan's periapse precession period (703 years), Saturn's heliocentric orbital period (29.47 years), perturbations from relatively large satellites Iapetus (79.3 days), and a 4:3 mean motion resonant interaction with Hyperion (640 and 6850 days), and a linear increase at Titan's mean orbital period (15.9455 day). Our rotation model for Titan has 4 free parameters. Two of them specify the orientation of the fixed spin pole, and the other two are the effective free libration period and viscous damping time. Our dynamical model includes a damped forced longitudinal libration, in which gravitational torques attempt to align the axis of least inertia with the instantaneous direction to Saturn. For a rigid tri-axial body, with Titan's moments of inertia, the free oscillation period for longitudinal librations would be 850 days. For a decoupled elastic shell, the effective

Titan gravity investigation with the Oceanus mission

NASA Astrophysics Data System (ADS)

Tortora, Paolo; Zannoni, Marco; Nimmo, Francis; Mazarico, Erwan; Iess, Luciano; Sotin, Christophe; Hayes, Alexander; Malaska, Michael

2017-04-01

Oceanus is a proposed mission for NASA's New Frontiers 4 Announcement of Opportunity to study Saturn's largest moon Titan. One of the main goals of Oceanus is to examine crustal properties and determine the potential interaction of organics with the subsurface ocean, with implications for potential habitability of Titan. To this end, Oceanus could potentially characterize the thickness of the external icy shell and determine the extent of convection in the shell. The product (average ice rigidity) x (ice shell thickness) can be retrieved from the Love numbers k2 and h2, which describe Titan's gravity and shape response to Saturn's tidal field during its orbital motion around the planet, using a combined analysis of gravity and topography but also measuring Titan's physical librations from gravity data and the on-board camera surface landmarks. The gravity science experiment is crucial to accomplish the mission goals, because precise orbit determination of the spacecraft provides a direct measure of Titan's static gravitational field, the real and imaginary parts of the Love number k2, and its rotational state (obliquity and amplitude of physical librations in longitude). Moreover, a precise spacecraft orbit reconstruction throughout the entire mission is necessary to process radar altimetry data and accurately measure Titan's h2 through crossover analysis. We present the expected accuracy in the estimation of the scientific parameters of interest, obtained through numerical simulations of the orbit determination of the Oceanus spacecraft during its 2-year mission around Titan. The main observable quantities used in the analysis are two-way Doppler data obtained from the frequency shift of a highly stable microwave carrier between the spacecraft and the stations of NASA's Deep Space Network. White Gaussian noise was added to the simulated data, with a realistic standard deviation obtained from an accurate noise budget derived from the experience with Cassini Ka

Raising the Titanic.

ERIC Educational Resources Information Center

Baker, Romona

1990-01-01

Described is an activity in which groups of students investigate engineering principles by writing a feasibility study to raise the luxury liner, Titanic. The problem statement and directions, and suggestions for problem solutions are included. (CW)

Evidence of Temporal Variation of Titan Atmospheric Density in 2005-2013

NASA Technical Reports Server (NTRS)

Lee, Allan Y.; Lim, Ryan S.

2013-01-01

One major science objective of the Cassini mission is an investigation of Titan's atmosphere constituent abundances. Titan's atmospheric density is of interest not only to planetary scientists but also to mission design and mission control engineers. Knowledge of the dependency of Titan's atmospheric density with altitude is important because any unexpectedly high atmospheric density has the potential to tumble the spacecraft during a flyby. During low-altitude Titan flyby, thrusters are fired to counter the torque imparted on the spacecraft due to the Titan atmosphere. The denser the Titan's atmosphere is, the higher are the duty cycles of the thruster firings. Therefore thruster firing telemetry data could be used to estimate the atmospheric torque imparted on the spacecraft. Since the atmospheric torque imparted on the spacecraft is related to the Titan's atmospheric density, atmospheric densities are estimated accordingly. In 2005-2013, forty-three low-altitude Titan flybys were executed. The closest approach altitudes of these Titan flybys ranged from 878 to 1,074.8 km. Our density results are also compared with those reported by other investigation teams: Voyager-1 (in November 1980) and the Huygens Atmospheric Structure Instrument, HASI (in January 2005). From our results, we observe a temporal variation of the Titan atmospheric density in 2005-2013. The observed temporal variation is significant and it isn't due to the estimation uncertainty (5.8%, 1 sigma) of the density estimation methodology. Factors that contributed to this temporal variation have been conjectured but are largely unknown. The observed temporal variation will require synergetic analysis with measurements made by other Cassini science instruments and future years of laboratory and modeling efforts to solve. The estimated atmospheric density results are given in this paper help scientists to better understand and model the density structure of the Titan atmosphere.

Polyploid Titan Cells Produce Haploid and Aneuploid Progeny To Promote Stress Adaptation

PubMed Central

Gerstein, Aleeza C.; Fu, Man Shun; Mukaremera, Liliane; Li, Zhongming; Ormerod, Kate L.; Fraser, James A.; Berman, Judith

2015-01-01

ABSTRACT Cryptococcus neoformans is a major life-threatening fungal pathogen. In response to the stress of the host environment, C. neoformans produces large polyploid titan cells. Titan cell production enhances the virulence of C. neoformans, yet whether the polyploid aspect of titan cells is specifically influential remains unknown. We show that titan cells were more likely to survive and produce offspring under multiple stress conditions than typical cells and that even their normally sized daughters maintained an advantage over typical cells in continued exposure to stress. Although polyploid titan cells generated haploid daughter cell progeny upon in vitro replication under nutrient-replete conditions, titan cells treated with the antifungal drug fluconazole produced fluconazole-resistant diploid and aneuploid daughter cells. Interestingly, a single titan mother cell was capable of generating multiple types of aneuploid daughter cells. The increased survival and genomic diversity of titan cell progeny promote rapid adaptation to new or high-stress conditions. PMID:26463162

Titan's surface at 2.2-cm wavelength imaged by the Cassini RADAR radiometer: Calibration and first results

USGS Publications Warehouse

Janssen, M.A.; Lorenz, R.D.; West, R.; Paganelli, F.; Lopes, R.M.; Kirk, R.L.; Elachi, C.; Wall, S.D.; Johnson, W.T.K.; Anderson, Y.; Boehmer, R.A.; Callahan, P.; Gim, Y.; Hamilton, G.A.; Kelleher, K.D.; Roth, L.; Stiles, B.; Le, Gall A.

2009-01-01

The first comprehensive calibration and mapping of the thermal microwave emission from Titan's surface is reported based on radiometric data obtained at 2.2-cm wavelength by the passive radiometer included in the Cassini Radar instrument. The data reported were accumulated from 69 separate observational segments in Titan passes from Ta (October 2004) through T30 (May 2007) and include emission from 94% of Titan's surface. They are diverse in the key observing parameters of emission angle, polarization, and spatial resolution, and their reduction into calibrated global mosaic maps involved several steps. Analysis of the polarimetry obtained at low to moderate resolution (50+ km) enabled integration of the radiometry into a single mosaic of the equivalent brightness temperature at normal incidence with a relative precision of about 1 K. The Huygens probe measurement of Titan's surface temperature and radiometry obtained on Titan's dune fields allowed us to infer an absolute calibration estimated to be accurate to a level approaching 1 K. The results provide evidence for a surface that is complex and varied on large scales. The radiometry primarily constrains physical properties of the surface, where we see strong evidence for subsurface (volume) scattering as a dominant mechanism that determines the emissivity, with the possibility of a fluffy or graded-density surface layer in many regions. The results are consistent with, but not necessarily definitive of a surface composition resulting from the slow deposition and processing of organic compounds from the atmosphere. ?? 2008 Elsevier Inc.

Titan's atmosphere (clouds and composition): new results

NASA Astrophysics Data System (ADS)

Griffith, C. A.

Titan's atmosphere potentially sports a cycle similar to the hydrologic one on Earth with clouds, rain and seas, but with methane playing the terrestrial role of water. Over the past ten years many independent efforts indicated no strong evidence for cloudiness until some unique spectra were analyzed in 1998 (Griffith et al.). These surprising observations displayed enhanced fluxes of 14-200 % on two nights at precisely the wavelengths (windows) that sense Titan's lower altitude where clouds might reside. The morphology of these enhancements in all 4 windows observed indicate that clouds covered ~6-9 % of Titan's surface and existed at ~15 km altitude. Here I discuss new observations recorded in 1999 aimed to further characterize Titan's clouds. While we find no evidence for a massive cloud system similar to the one observed previously, 1%-4% fluctuations in flux occur daily. These modulations, similar in wavelength and morphology to the more pronounced ones observed earlier, suggest the presence of clouds covering ≤1% of Titan's disk. The variations are too small to have been detected by most prior measurements. Repeated observations, spaced 30 minutes apart, indicate a temporal variability observable in the time scale of a couple of hours. The cloud heights hint that convection might govern their evolution. Their short lives point to the presence of rain.

Differences between evolution of Titan's and Earth's rivers - further conclusions

NASA Astrophysics Data System (ADS)

Misiura, Katarzyna; Czechowski, Leszek

2014-05-01

Titan is the only celestial body, beside the Earth, where liquid is present on the surface. Liquid forms a number of lakes and rivers. In our research we use numerical model of the river to determine differences of evolution of rivers on the Earth and on Titan. We have found that transport of sediments on Titan is more effective than on Earth for the same river geometry and discharge. We have found also the theoretical explanations for this conclusion. 2.Introduction Titan is a very special body in the Solar System. It is the only moon that has dense atmosphere and flowing liquid on its surface. The Cassini-Huygens mission has found on Titan meandering rivers, and indicated processes of erosion, transport of solid material and its sedimentation. This paper is aimed to investigate the similarity and differences between these processes on Titan and the Earth. 3. Basic equations of our model The dynamical analysis of the considered rivers is performed using the package CCHE modified for the specific conditions on Titan. The package is based on the Navier-Stokes equations for depth-integrated two dimensional, turbulent flow and three dimensional convection-diffusion equation of sediment transport. 4. Parameters of the model We considered our model for a few kinds of liquid found on Titan. The liquid that falls as a rain (75% methane, 25% nitrogen) has different properties than the fluid forming lakes (74% ethane, 10% methane, 7% propane, 8.5% butane, 0.5% nitrogen). Other parameters of our model are: inflow discharge, outflow level, grain size of sediments etc. For every calculation performed for Titan's river similar calculations are performed for terrestrial ones. 5. Results and Conclusions The results of our simulation show the differences in behaviour of the flow and of sedimentation on Titan and on the Earth. Our preliminary results indicate that transport of material by Titan's rivers is more efficient than by terrestrial rivers of the same geometry parameters

Titan Two Halves

NASA Image and Video Library

2010-05-13

Two different seasons on Titan in different hemispheres can be seen in this image. The moon northern half appears slightly darker than the southern half in this view taken in visible blue light by NASA Cassini spacecraft.

Polyploid titan cells produce haploid and aneuploid progeny to promote stress adaptation.

PubMed

Gerstein, Aleeza C; Fu, Man Shun; Mukaremera, Liliane; Li, Zhongming; Ormerod, Kate L; Fraser, James A; Berman, Judith; Nielsen, Kirsten

2015-10-13

Cryptococcus neoformans is a major life-threatening fungal pathogen. In response to the stress of the host environment, C. neoformans produces large polyploid titan cells. Titan cell production enhances the virulence of C. neoformans, yet whether the polyploid aspect of titan cells is specifically influential remains unknown. We show that titan cells were more likely to survive and produce offspring under multiple stress conditions than typical cells and that even their normally sized daughters maintained an advantage over typical cells in continued exposure to stress. Although polyploid titan cells generated haploid daughter cell progeny upon in vitro replication under nutrient-replete conditions, titan cells treated with the antifungal drug fluconazole produced fluconazole-resistant diploid and aneuploid daughter cells. Interestingly, a single titan mother cell was capable of generating multiple types of aneuploid daughter cells. The increased survival and genomic diversity of titan cell progeny promote rapid adaptation to new or high-stress conditions. The ability to adapt to stress is a key element for survival of pathogenic microbes in the host and thus plays an important role in pathogenesis. Here we investigated the predominantly haploid human fungal pathogen Cryptococcus neoformans, which is capable of ploidy and cell size increases during infection through production of titan cells. The enlarged polyploid titan cells are then able to rapidly undergo ploidy reduction to generate progeny with reduced ploidy and/or aneuploidy. Under stressful conditions, titan cell progeny have a growth and survival advantage over typical cell progeny. Understanding how titan cells enhance the rate of cryptococcal adaptation under stress conditions may assist in the development of novel drugs aimed at blocking ploidy transitions. Copyright © 2015 Gerstein et al.

The organic aerosols of Titan

NASA Technical Reports Server (NTRS)

Khare, B. N.; Sagan, C.; Thompson, W. R.; Arakawa, E. T.; Suits, F.; Calcott, T. A.; Williams, M. W.; Shrader, S.; Ogino, H.; Willingham, T. O.

1986-01-01

A dark reddish organic solid, called tholin, is synthesized from simulated Titanian atmospheres by irradiation with high energy electrons in a plasma discharge. The visible reflection spectrum of this tholin is found to be similar to that of high altitude aerosols responsible for the albedo and reddish color of Titan. The real (n) and imaginary (k) parts of the complex refractive index of thin films of Titan prepared by continuous dc discharge through a 0.9 N2/0.1 CH4 gas mixture at 0.2 mb is determined from X-ray to microwave frequencies. Values of n (approx. 1.65) and k (approx. 0.004 to 0.08) in the visible are consistent with deductions made by groundbased and spaceborne observations of Titan. Many infrared absorption features are present in k(lambda), including the 4.6 micrometer nitrile band. Molecular analysis of the volatile components of this tholin was performed by sequential and nonsequential pyrolytic gas chromatography/mass spectrometry. More than one hundred organic compounds are released; tentative identifications include saturated and unsaturated aliphatic hydrocarbons, substituted polycylic aromatics, nitriles, amines, pyrroles, pyrazines, pyridines, pyrimidines, and the purine, adenine. In addition,acid hydrolysis produces a racemic mixture of biological and nonbiological amino acids. Many of these molecules are implicated in the origin of life on Earth, suggesting Titan as a contemporary laboratory environment for prebiological organic chemistry on a planetary scale.

Titan Aeromony and Climate Workshop

NASA Astrophysics Data System (ADS)

Bézard, Bruno; Lavvas, Panayotis; Rannou, Pascal; Sotin, Christophe; Strobel, Darrell; West, Robert A.; Yelle, Roger

2016-06-01

The observations of the Cassini spacecraft since 2004 revealed that Titan, the largest moon of Saturn, has an active climate cycle with a cloud cover related to the large scale atmospheric circulation, lakes of methane and hyrdrocarbons with variable depth, a dried fluvial system witnessing a past wetter climate, dunes, and deep changes in the weather and atmospheric structure as Titan went through the North Spring equinox. Moreover, the upper atmosphere is now considered the cradle of complex chemistry leading to aerosol formation, as well as the manifestation place of atmospheric waves. However, as the Cassini mission comes to its end, many fundamental questions remain unresolved... The objective of the workshop is to bring together international experts from different fields of Titan's research in order to have an overview of the current understanding, and to determine the remaining salient scientific issues and the actions that could be implemented to address them. PhD students and post-doc researchers are welcomed to present their studies. This conference aims to be a brainstorming event leaving abundant time for discussion during oral and poster presentations. Main Topics: - Atmospheric seasonal cycles and coupling with dynamics. - Composition and photochemistry of the atmosphere. - Formation and evolution of aerosols and their role in the atmosphere. - Spectroscopy, optical properties, and radiative transfer modeling of the atmosphere. - Surface composition, liquid reservoirs and interaction with atmosphere. - Evolution of the atmosphere. - Titan after Cassini, open questions and the path forward.

Titan's Topside Ionospheric Composition: Cassini Plasma Spectrometer Ion Mass Spectrometer Measurements

NASA Astrophysics Data System (ADS)

Sittler, Edward; Hartle, Richard; Ali, Ashraf; Cooper, John; Lipatov, Alexander; Simpson, David; Sarantos, Menelaos; Chornay, Dennis; Smith, Todd

2017-01-01

We present ion composition measurements of Titan's topside ionosphere using both T9 and T15 Cassini Plasma Spectrometer (CAPS) Ion Mass Spectrometer (IMS) measurements. The IMS is able to make measurements of Titan's ionosphere due to ionospheric outflows as originally reported for the T9 flyby. This allows one to take advantage of the unique capabilities of the CAPS IMS which measures both the mass-per-charge (M/Q) of the ions and the fragments of the ions produced inside the sensor such as carbon, nitrogen and oxygen fragments. Specific attention will be given to such ions as NH4 +, N +, O +, CH4 +, CxHy +, and HCNH + ions as examples. The CAPS IMS uses a time-of-flight (TOF) technique which accelerates ions up to 14.6 kV, so they can pass through ultra-thin carbon foils. Neutral fragments are used to measure the ion M/Q and positive fragments to measure the atomic components. We preliminarily find, by using IMS measurements of T9 and T15 ionospheric outflows, evidence for methane group ions, nitrogen ions, ammonium ions, water group ions and CnHm + ions with n = 2, 3, and 4 within Titan's topside ionosphere. E.C. Sittler acknowledges support at Goddard Space Flight Center by the CAPS Cassini Project from JPL funds under contract # NAS703001TONMO711123/1405851.

Titan Lifting Entry & Atmospheric Flight (T-LEAF) Science Mission

NASA Astrophysics Data System (ADS)

Lee, G.; Sen, B.; Ross, F.; Sokol, D.

2016-12-01

Northrop Grumman has been developing the Titan Lifting Entry & Atmospheric Flight (T-LEAF) sky rover to roam the lower atmosphere and observe at close quarters the lakes and plains of Saturn's ocean moon, Titan. T-LEAF also supports surface exploration and science by providing precision delivery of in-situ instruments to the surface of Titan. T-LEAF is a highly maneuverable sky rover and its aerodynamic shape (i.e., a flying wing) does not restrict it to following prevailing wind patterns on Titan, but allows mission operators to chart its course. This freedom of mobility allows T-LEAF to follow the shorelines of Titan's methane lakes, for example, or to target very specific surface locations. We will present a straw man concept of T-LEAF, including size, mass, power, on-board science payloads and measurement, and surface science dropsonde deployment CONOPS. We will discuss the various science instruments and their vehicle level impacts, such as meteorological and electric field sensors, acoustic sensors for measuring shallow depths, multi-spectral imagers, high definition cameras and surface science dropsondes. The stability of T-LEAF and its long residence time on Titan will provide for time to perform a large aerial survey of select prime surface targets deployment of dropsondes at selected locations surface measurements that are coordinated with on-board remote measurements communication relay capabilities to orbiter (or Earth). In this context, we will specifically focus upon key factors impacting the design and performance of T-LEAF science: science payload accommodation, constraints and opportunities characteristics of flight, payload deployment and measurement CONOPS in the Titan atmosphere. This presentation will show how these factors provide constraints as well as enable opportunities for novel long duration scientific studies of Titan's surface.

Biologically Enhanced Energy and Carbon Cycling on Titan?

NASA Astrophysics Data System (ADS)

Schulze-Makuch, Dirk; Grinspoon, David H.

2005-08-01

With the Cassini-Huygens Mission in orbit around Saturn, the large moon Titan, with its reducing atmosphere, rich organic chemistry, and heterogeneous surface, moves into the astrobiological spotlight. Environmental conditions on Titan and Earth were similar in many respects 4 billion years ago, the approximate time when life originated on Earth. Life may have originated on Titan during its warmer early history and then developed adaptation strategies to cope with the increasingly cold conditions. If organisms originated and persisted, metabolic strategies could exist that would provide sufficient energy for life to persist, even today. Metabolic reactions might include the catalytic hydrogenation of photochemically produced acetylene, or involve the recombination of radicals created in the atmosphere by ultraviolet radiation. Metabolic activity may even contribute to the apparent youth, smoothness, and high activity of Titan's surface via biothermal energy.

Biologically enhanced energy and carbon cycling on Titan?

PubMed

Schulze-Makuch, Dirk; Grinspoon, David H

2005-08-01

With the Cassini-Huygens Mission in orbit around Saturn, the large moon Titan, with its reducing atmosphere, rich organic chemistry, and heterogeneous surface, moves into the astrobiological spotlight. Environmental conditions on Titan and Earth were similar in many respects 4 billion years ago, the approximate time when life originated on Earth. Life may have originated on Titan during its warmer early history and then developed adaptation strategies to cope with the increasingly cold conditions. If organisms originated and persisted, metabolic strategies could exist that would provide sufficient energy for life to persist, even today. Metabolic reactions might include the catalytic hydrogenation of photochemically produced acetylene, or involve the recombination of radicals created in the atmosphere by ultraviolet radiation. Metabolic activity may even contribute to the apparent youth, smoothness, and high activity of Titan's surface via biothermal energy.

Evidence for a polar ethane cloud on Titan

USGS Publications Warehouse

Griffith, C.A.; Penteado, P.; Rannou, P.; Brown, R.; Boudon, V.; Baines, K.H.; Clark, R.; Drossart, P.; Buratti, B.; Nicholson, P.; McKay, C.P.; Coustenis, A.; Negrao, A.; Jaumann, R.

2006-01-01

Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal the presence of a vast tropospheric cloud on Titan at latitudes 51?? to 68?? north and all longitudes observed (10?? to 190?? west). The derived characteristics indicate that this cloud is composed of ethane and forms as a result of stratospheric subsidence and the particularly cool conditions near the moon's north pole. Preferential condensation of ethane, perhaps as ice, at Titan's poles during the winters may partially explain the lack of liquid ethane oceans on Titan's surface at middle and lower latitudes.

Evidence for a polar ethane cloud on Titan.

PubMed

Griffith, C A; Penteado, P; Rannou, P; Brown, R; Boudon, V; Baines, K H; Clark, R; Drossart, P; Buratti, B; Nicholson, P; McKay, C P; Coustenis, A; Negrao, A; Jaumann, R

2006-09-15

Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal the presence of a vast tropospheric cloud on Titan at latitudes 51 degrees to 68 degrees north and all longitudes observed (10 degrees to 190 degrees west). The derived characteristics indicate that this cloud is composed of ethane and forms as a result of stratospheric subsidence and the particularly cool conditions near the moon's north pole. Preferential condensation of ethane, perhaps as ice, at Titan's poles during the winters may partially explain the lack of liquid ethane oceans on Titan's surface at middle and lower latitudes.

The identification of liquid ethane in Titan's Ontario Lacus

USGS Publications Warehouse

Brown, R.H.; Soderblom, L.A.; Soderblom, J.M.; Clark, R.N.; Jaumann, R.; Barnes, J.W.; Sotin, Christophe; Buratti, B.; Baines, K.H.; Nicholson, P.D.

2008-01-01

Titan was once thought to have global oceans of light hydrocarbons on its surface, but after 40 close flybys of Titan by the Cassini spacecraft, it has become clear that no such oceans exist. There are, however, features similar to terrestrial lakes and seas, and widespread evidence for fluvial erosion, presumably driven by precipitation of liquid methane from Titan's dense, nitrogen-dominated atmosphere. Here we report infrared spectroscopic data, obtained by the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft, that strongly indicate that ethane, probably in liquid solution with methane, nitrogen and other low-molecular-mass hydrocarbons, is contained within Titan's Ontario Lacus. ??2008 Macmillan Publishers Limited. All rights reserved.

Hydrocarbon lakes on Titan

NASA Astrophysics Data System (ADS)

Mitri, Giuseppe; Showman, Adam P.; Lunine, Jonathan I.; Lorenz, Ralph D.

2007-02-01

The Huygens Probe detected dendritic drainage-like features, methane clouds and a high surface relative humidity (∼50% ) on Titan in the vicinity of its landing site [Tomasko, M.G., and 39 colleagues, 2005. Nature 438, 765-778; Niemann, H.B., and 17 colleagues, 2005. Nature 438, 779-784], suggesting sources of methane that replenish this gas against photo- and charged-particle chemical loss on short (10-100) million year timescales [Atreya, S.K., Adams, E.Y., Niemann, H.B., Demick-Montelara, J.E., Owen, T.C., Fulchignoni, M., Ferri, F., Wilson, E.H., 2006. Planet. Space Sci. In press]. On the other hand, Cassini Orbiter remote sensing shows dry and even desert-like landscapes with dunes [Lorenz, R.D., and 39 colleagues, 2006a. Science 312, 724-727], some areas worked by fluvial erosion, but no large-scale bodies of liquid [Elachi, C., and 34 colleagues, 2005. Science 308, 970-974]. Either the atmospheric methane relative humidity is declining in a steady fashion over time, or the sources that maintain the relative humidity are geographically restricted, small, or hidden within the crust itself. In this paper we explore the hypothesis that the present-day methane relative humidity is maintained entirely by lakes that cover a small part of the surface area of Titan. We calculate the required minimum surface area coverage of such lakes, assess the stabilizing influence of ethane, and the implications for moist convection in the atmosphere. We show that, under Titan's surface conditions, methane evaporates rapidly enough that shorelines of any existing lakes could potentially migrate by several hundred m to tens of km per year, rates that could be detected by the Cassini orbiter. We furthermore show that the high relative humidity of methane in Titan's lower atmosphere could be maintained by evaporation from lakes covering only 0.002-0.02 of the whole surface.

The trading company in space development in Japan

NASA Astrophysics Data System (ADS)

Gonda, Toshi N.

Trading companies have a unique status in the Japanese market and a really deep involvement in Japanese trade. They are also involved in space development and the space industry as well. An overview of trading companies activities and, more specifically, a way of involving them more in the space industry are presented. The activities of Nissho Iwai Corporation, one of the Sogo Shosha, are described in detail. Their activities in the space industry have two aspects, one is social and the other is commercial. They have been stimulating space projects in these aspects. There are several international cooperative space projects between Japan and the U.S. These projects are proceeding on a government to government basis. But, it is worthwhile to realize that the Sogo Shosha may create trade flow through increased international space cooperation in the private sector.

Chapman Solar Zenith Angle variations at Titan

NASA Astrophysics Data System (ADS)

Royer, Emilie M.; Ajello, Joseph; Holsclaw, Gregory; West, Robert; Esposito, Larry W.; Bradley, Eric Todd

2016-10-01

Solar XUV photons and magnetospheric particles are the two main sources contributing to the airglow in the Titan's upper atmosphere. We are focusing here on the solar XUV photons and how they influence the airglow intensity. The Cassini-UVIS observations analyzed in this study consist each in a partial scan of Titan, while the center of the detector stays approximately at the same location on Titan's disk. We used observations from 2008 to 2012, which allow for a wide range of Solar Zenith Angle (SZA). Spectra from 800 km to 1200 km of altitude have been corrected from the solar spectrum using TIMED/SEE data. We observe that the airglow intensity varies as a function of the SZA and follows a Chapman curve. Three SZA regions are identified: the sunlit region ranging from 0 to 50 degrees. In this region, the intensity of the airglow increases, while the SZA decreases. Between SZA 50 and 100 degrees, the airglow intensity decreases from it maximum to its minimum. In this transition region the upper atmosphere of Titan changes from being totally sunlit to being in the shadow of the moon. For SZA 100 to 180 degrees, we observe a constant airglow intensity close to zero. The behavior of the airglow is also similar to the behavior of the electron density as a function of the SZA as observed by Ågren at al (2009). Both variables exhibit a decrease intensity with increasing SZA. The goal of this study is to understand such correlation. We demonstrate the importance of the solar XUV photons contribution to the Titan airglow and prove that the strongest contribution to the Titan dayglow occurs by solar fluorescence rather than the particle impact that predominates at night.

TP Atlas: integration and dissemination of advances in Targeted Proteins Research Program (TPRP)-structural biology project phase II in Japan.

PubMed

Iwayanagi, Takao; Miyamoto, Sei; Konno, Takeshi; Mizutani, Hisashi; Hirai, Tomohiro; Shigemoto, Yasumasa; Gojobori, Takashi; Sugawara, Hideaki

2012-09-01

The Targeted Proteins Research Program (TPRP) promoted by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan is the phase II of structural biology project (2007-2011) following the Protein 3000 Project (2002-2006) in Japan. While the phase I Protein 3000 Project put partial emphasis on the construction and maintenance of pipelines for structural analyses, the TPRP is dedicated to revealing the structures and functions of the targeted proteins that have great importance in both basic research and industrial applications. To pursue this objective, 35 Targeted Proteins (TP) Projects selected in the three areas of fundamental biology, medicine and pharmacology, and food and environment are tightly collaborated with 10 Advanced Technology (AT) Projects in the four fields of protein production, structural analyses, chemical library and screening, and information platform. Here, the outlines and achievements of the 35 TP Projects are summarized in the system named TP Atlas. Progress in the diversified areas is described in the modules of Graphical Summary, General Summary, Tabular Summary, and Structure Gallery of the TP Atlas in the standard and unified format. Advances in TP Projects owing to novel technologies stemmed from AT Projects and collaborative research among TP Projects are illustrated as a hallmark of the Program. The TP Atlas can be accessed at http://net.genes.nig.ac.jp/tpatlas/index_e.html .

Titan's inventory of organic surface materials

USGS Publications Warehouse

Lorenz, R.D.; Mitchell, K.L.; Kirk, R.L.; Hayes, A.G.; Aharonson, O.; Zebker, H.A.; Paillou, P.; Radebaugh, J.; Lunine, J.I.; Janssen, M.A.; Wall, S.D.; Lopes, R.M.; Stiles, B.; Ostro, S.; Mitri, Giuseppe; Stofan, E.R.

2008-01-01

Cassini RADAR observations now permit an initial assessment of the inventory of two classes, presumed to be organic, of Titan surface materials: polar lake liquids and equatorial dune sands. Several hundred lakes or seas have been observed, of which dozens are each estimated to contain more hydrocarbon liquid than the entire known oil and gas reserves on Earth. Dark dunes cover some 20% of Titan's surface, and comprise a volume of material several hundred times larger than Earth's coal reserves. Overall, however, the identified surface inventories (>3 ?? 104 km3 of liquid, and >2 ?? 105 km3 of dune sands) are small compared with estimated photochemical production on Titan over the age of the solar system. The sand volume is too large to be accounted for simply by erosion in observed river channels or ejecta from observed impact craters. The lakes are adequate in extent to buffer atmospheric methane against photolysis in the short term, but do not contain enough methane to sustain the atmosphere over geologic time. Unless frequent resupply from the interior buffers this greenhouse gas at exactly the right rate, dramatic climate change on Titan is likely in its past, present and future. Copyright 2008 by the American Geophysical Union.

Chemical evolution on Titan: comparisons to the prebiotic earth.

PubMed

Clarke, D W; Ferris, J P

1997-06-01

Models for the origin of Titan's atmosphere, the processing of the atmosphere and surface and its exobiological role are reviewed. Titan has gained widespread acceptance in the origin of life field as a model for the types of evolutionary processes that could have occurred on prebiotic Earth. Both Titan and Earth possess significant atmospheres (> or = 1 atm) composed mainly of molecular nitrogen with smaller amounts of more reactive species. Both of these atmospheres are processed primarily by solar ultraviolet light with high energy particles interactions contributing to a lesser extent. The products of these reactions condense or are dissolved in other atmospheric species (aerosols/clouds) and fall to the surface. There these products may have been further processed on Titan and the primitive Earth by impacting comets and meteorites. While the low temperatures on Titan (approximately 72-180 K) preclude the presence of permanent liquid water on the surface, it has been suggested that tectonic activity or impacts by meteors and comets could produce liquid water pools on the surface for thousands of years. Hydrolysis and oligomerization reactions in these pools might form chemicals of prebiological significance. Other direct comparisons between the conditions on present day Titan and those proposed for prebiotic Earth are also presented.

Titan Kraken Mare

NASA Image and Video Library

2011-11-28

NASA Cassini spacecraft looks toward Saturn largest moon, Titan, and spies the huge Kraken Mare in the moon north. Kraken Mare, a large sea of liquid hydrocarbons, is visible as a dark area near the top of the image.

N2 state population in Titan's atmosphere

NASA Astrophysics Data System (ADS)

Lavvas, P.; Yelle, R. V.; Heays, A. N.; Campbell, L.; Brunger, M. J.; Galand, M.; Vuitton, V.

2015-11-01

We present a detailed model for the vibrational population of all non pre-dissociating excited electronic states of N2, as well as for the ground and ionic states, in Titan's atmosphere. Our model includes the detailed energy deposition calculations presented in the past (Lavvas, P. et al. [2011]. Icarus 213(1), 233-251) as well as the more recent developments in the high resolution N2 photo-absorption cross sections that allow us to calculate photo-excitation rates for different vibrational levels of singlet nitrogen states, and provide information for their pre-dissociation yields. In addition, we consider the effect of collisions and chemical reactions in the population of the different states. Our results demonstrate that above 600 km altitude, collisional processes are efficient only for a small sub-set of the excited states limited to the A and W(ν = 0) triplet states, and to a smaller degree to the a‧ singlet state. In addition, we find that a significant population of vibrationally excited ground state N2 survives in Titan's upper atmosphere. Our calculations demonstrate that this hot N2 population can improve the agreement between models and observations for the emission of the c4‧ state that is significantly affected by resonant scattering. Moreover we discuss the potential implications of the vibrationally excited population on the ionospheric densities.

The seasonal cycle of Titan's detached haze

NASA Astrophysics Data System (ADS)

West, Robert A.; Seignovert, Benoît.; Rannou, Pascal; Dumont, Philip; Turtle, Elizabeth P.; Perry, Jason; Roy, Mou; Ovanessian, Aida

2018-06-01

Titan's `detached' haze, seen in Voyager images in 1980 and 1981 and monitored by the Cassini Imaging Science Subsystem (ISS) during the period 2004-2017, provides a measure of seasonal activity in Titan's mesosphere with observations over almost half of Saturn's seasonal cycle. Here we report on retrieved haze extinction profiles that reveal a depleted layer (having a diminished aerosol content), visually manifested as a gap between the main haze and a thin, detached upper layer. Our measurements show the disappearance of the feature in 2012 and its reappearance in 2016, as well as details after the reappearance. These observations highlight the dynamical nature of the detached haze. The reappearance seems congruent with earlier descriptions by climate models but more complex than previously described. It occurs in two steps, first as haze reappearing at 450 ± 20 km and one year later at 510 ± 20 km. These observations provide additional tight and valuable constraints about the underlying mechanisms, especially for Titan's mesosphere, that control Titan's haze cycle.

Dunes on Titan observed by Cassini Radar

USGS Publications Warehouse

Radebaugh, J.; Lorenz, R.D.; Lunine, J.I.; Wall, S.D.; Boubin, G.; Reffet, E.; Kirk, R.L.; Lopes, R.M.; Stofan, E.R.; Soderblom, L.; Allison, M.; Janssen, M.; Paillou, P.; Callahan, P.; Spencer, C.; ,

2008-01-01

Thousands of longitudinal dunes have recently been discovered by the Titan Radar Mapper on the surface of Titan. These are found mainly within ??30?? of the equator in optically-, near-infrared-, and radar-dark regions, indicating a strong proportion of organics, and cover well over 5% of Titan's surface. Their longitudinal duneform, interactions with topography, and correlation with other aeolian forms indicate a single, dominant wind direction aligned with the dune axis plus lesser, off-axis or seasonally alternating winds. Global compilations of dune orientations reveal the mean wind direction is dominantly eastwards, with regional and local variations where winds are diverted around topographically high features, such as mountain blocks or broad landforms. Global winds may carry sediments from high latitude regions to equatorial regions, where relatively drier conditions prevail, and the particles are reworked into dunes, perhaps on timescales of thousands to tens of thousands of years. On Titan, adequate sediment supply, sufficient wind, and the absence of sediment carriage and trapping by fluids are the dominant factors in the presence of dunes. ?? 2007 Elsevier Inc. All rights reserved.

The seasonal cycle of Titan's detached haze

NASA Astrophysics Data System (ADS)

West, Robert A.; Seignovert, Benoît; Rannou, Pascal; Dumont, Philip; Turtle, Elizabeth P.; Perry, Jason; Roy, Mou; Ovanessian, Aida

2018-04-01

Titan's `detached' haze, seen in Voyager images in 1980 and 1981 and monitored by the Cassini Imaging Science Subsystem (ISS) during the period 2004-2017, provides a measure of seasonal activity in Titan's mesosphere with observations over almost half of Saturn's seasonal cycle. Here we report on retrieved haze extinction profiles that reveal a depleted layer (having a diminished aerosol content), visually manifested as a gap between the main haze and a thin, detached upper layer. Our measurements show the disappearance of the feature in 2012 and its reappearance in 2016, as well as details after the reappearance. These observations highlight the dynamical nature of the detached haze. The reappearance seems congruent with earlier descriptions by climate models but more complex than previously described. It occurs in two steps, first as haze reappearing at 450 ± 20 km and one year later at 510 ± 20 km. These observations provide additional tight and valuable constraints about the underlying mechanisms, especially for Titan's mesosphere, that control Titan's haze cycle.

Mountains on Titan observed by Cassini Radar

USGS Publications Warehouse

Radebaugh, J.; Lorenz, R.D.; Kirk, R.L.; Lunine, J.I.; Stofan, E.R.; Lopes, R.M.C.; Wall, S.D.

2007-01-01

The Cassini Titan Radar mapper has observed elevated blocks and ridge-forming block chains on Saturn's moon Titan demonstrating high topography we term "mountains." Summit flanks measured from the T3 (February 2005) and T8 (October 2005) flybys have a mean maximum slope of 37?? and total elevations up to 1930 m as derived from a shape-from-shading model corrected for the probable effects of image resolution. Mountain peak morphologies and surrounding, diffuse blankets give evidence that erosion has acted upon these features, perhaps in the form of fluvial runoff. Possible formation mechanisms for these mountains include crustal compressional tectonism and upthrusting of blocks, extensional tectonism and formation of horst-and-graben, deposition as blocks of impact ejecta, or dissection and erosion of a preexisting layer of material. All above processes may be at work, given the diversity of geology evident across Titan's surface. Comparisons of mountain and blanket volumes and erosion rate estimates for Titan provide a typical mountain age as young as 20-100 million years. ?? 2007 Elsevier Inc. All rights reserved.

Investigations into the photochemistry of the current and primordial atmosphere of Titan

NASA Astrophysics Data System (ADS)

Wilson, Eric Hezekiah

2002-08-01

A comprehensive steady-state one-dimensional photochemical model of the atmosphere of Titan has been developed. This model has included updated chemistry with a focus on rate coefficients and cross sections measured under conditions most applicable for simulation of Titan's atmosphere. Through this simulation, the physical and chemical processes which affect the altitudinal distribution of constituents in Titan's atmosphere have been explored. The model results, in comparison to previous Titan photochemical models, compares favorably with ground-based and fly-by observations of Titan's atmosphere. As a result, the model has facilitated the analysis of key questions regarding the nature of Titan's present chemistry, involving the production of key molecules and hazes. These questions include the role constituent density profiles may play in constraining methane photolysis quantum yields, the existence and formation mechanisms of benzene in Titan's atmosphere, and the chemical origin of Titan haze. Results show that the determination of CH3C2H and C3H6 abundance profiles will help constrain the CH quantum yield from methane photolysis, which varies significantly among photolytic schemes. Results also show that benzene can be formed in Titan's atmosphere, and the aromatic chemistry that ensues is the likely source of the Titan haze which enshrouds the surface. The origin of Titan's atmosphere has also been studied through a pseudo-time-dependent model which describes the evolution of the likely primordial ammonia inventory during the early stages of the solar system. Assuming an enhanced T-Tauri solar flux, the conversion of ammonia to nitrogen, in the presence of methane and water vapor, is found to be a plausible mechanism to account for the present-day nitrogen inventory. Results from this model are presented in preparation for the retrieval and interpretation of data from the Cassini- Huygens spacecraft, which will arrive at Titan in 2004.

A Saturnian gas ring and the recycling of Titan's atmosphere

NASA Technical Reports Server (NTRS)

Mcdonough, T. R.; Brice, N. M.

1973-01-01

Atoms which escape Titan's atmosphere are unlikely to possess escape velocity from Saturn and can orbit the planet until lost by ionization or collision with Titan. It is predicted that a toroidal ring of between 1 and 1,000 atoms or molecules per cubic centimeter exists around Saturn at a distance of about 10 times the radius of the visible rings. This torus may be detectable from earth orbit and detection or nondetection of it may provide some information about the presence or absence of a Saturnian magnetic field, and the exospheric temperature and atmospheric escape rate of Titan. It is estimated that, if Titan has a large exosphere, 97% or more of the escaping atoms can be recaptured by Titan, thereby decreasing the effective net atmospheric loss rate by up to two orders of magnitude. It is shown that, if Saturn has a magnetic field comparable to Jupiter's the magnetospheric plasma can supply Titan with hydrogen at a rate comparable to the loss rates in some of the models of Trafton (1972) and Sagan (1973).

Titan aerosol and gas experiment for the Huygens Probe

NASA Technical Reports Server (NTRS)

Carle, G. C.; Kojiro, D. R.; Oberbeck, V.; Ohara, B. J.; Pollack, J. B.; Valentin, J. R.; Bar-Nun, A.; Cohen, M. J.; Ferris, J. P.; Greenberg, J. M.

1991-01-01

The Cassini Mission is a joint undertaking of NASA and the European Space Agency (ESA) to explore the Saturnian System with a Saturn Orbiter and a Titan Probe. The launch vehicle and the Saturn Orbiter are the responsibility of NASA while the Huygens Probe (detachable Titan Probe) is the responsibility of ESA. The spacecraft will be launched in 1996 and the Huygens Probe will arrive at Titan in 2003. The Cassini Mission-Huygens Probe provides a unique opportunity to obtain detailed information about the atmosphere and, possibly, the surface of Titan. Titan possesses a substantial nitrogen atmosphere containing methane and many other organic compounds. Aerosols play an important role in the atmospheric processes on Titan. The Huygens Probe offers an opportunity to determine how organic particles are formed and grow which will clarify their role on Earth. A powerful analytical instrument, capable of addressing the above technology and other science questions, was recently proposed for the Huygens Probe. It is comprised of an aerosol and gas sampler and processor, and a gas chromatograph-ion mobility spectrometer. The instrument will be able to measure complex organics that make up the collected aerosols to the approximate 1 ppm level. Gases will be measured to approximately 10 ppb. Because the Titan atmosphere is expected to be quite complex, a gas chromatograph-ion mobility spectrometer is used to provide unequivocal identification of the components of the analytes. Further details of the science question to be investigated and the proposed instrument are described. The expected results and their implications are also addressed.

Landscape Evolution of Titan

NASA Technical Reports Server (NTRS)

Moore, Jeffrey

2012-01-01

Titan may have acquired its massive atmosphere relatively recently in solar system history. The warming sun may have been key to generating Titan's atmosphere over time, starting from a thin atmosphere with condensed surface volatiles like Triton, with increased luminosity releasing methane, and then large amounts of nitrogen (perhaps suddenly), into the atmosphere. This thick atmosphere, initially with much more methane than at present, resulted in global fluvial erosion that has over time retreated towards the poles with the removal of methane from the atmosphere. Basement rock, as manifested by bright, rough, ridges, scarps, crenulated blocks, or aligned massifs, mostly appears within 30 degrees of the equator. This landscape was intensely eroded by fluvial processes as evidenced by numerous valley systems, fan-like depositional features and regularly-spaced ridges (crenulated terrain). Much of this bedrock landscape, however, is mantled by dunes, suggesting that fluvial erosion no longer dominates in equatorial regions. High midlatitude regions on Titan exhibit dissected sedimentary plains at a number of localities, suggesting deposition (perhaps by sediment eroded from equatorial regions) followed by erosion. The polar regions are mainly dominated by deposits of fluvial and lacustrine sediment. Fluvial processes are active in polar areas as evidenced by alkane lakes and occasional cloud cover.

Grain Boundary Engineering of Lithium-Ion-Conducting Lithium Lanthanum Titanate for Lithium-Air Batteries

DTIC Science & Technology

2016-01-01

release; distribution is unlimited. 1 1. Introduction Lithium (Li)- ion batteries are currently one of the leading energy storage device technologies...ARL-TR-7584 ● JAN 2016 US Army Research Laboratory Grain Boundary Engineering of Lithium - Ion - Conducting Lithium Lanthanum...Titanate for Lithium -Air Batteries by Victoria L Blair, Claire V Weiss Brennan, and Joseph M Marsico Approved for public

Titan Radar Mapper observations from Cassini's T3 fly-by

USGS Publications Warehouse

Elachi, C.; Wall, S.; Janssen, M.; Stofan, E.; Lopes, R.; Kirk, R.; Lorenz, R.; Lunine, J.; Paganelli, F.; Soderblom, L.; Wood, C.; Wye, L.; Zebker, H.; Anderson, Y.; Ostro, S.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.; Kelleher, K.; Muhleman, D.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Stiles, B.; Vetrella, S.; West, R.

2006-01-01

Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be longitudinal dunes. Here we describe this great diversity of landforms. We conclude that much of the surface thus far imaged by radar of the haze-shrouded Titan is very young, with persistent geologic activity. ?? 2006 Nature Publishing Group.

Mission Techniques for Exploring Saturn's icy moons Titan and Enceladus

NASA Astrophysics Data System (ADS)

Reh, Kim; Coustenis, Athena; Lunine, Jonathan; Matson, Dennis; Lebreton, Jean-Pierre; Vargas, Andre; Beauchamp, Pat; Spilker, Tom; Strange, Nathan; Elliott, John

2010-05-01

The future exploration of Titan is of high priority for the solar system exploration community as recommended by the 2003 National Research Council (NRC) Decadal Survey [1] and ESA's Cosmic Vision Program themes. Cassini-Huygens discoveries continue to emphasize that Titan is a complex world with very many Earth-like features. Titan has a dense, nitrogen atmosphere, an active climate and meteorological cycles where conditions are such that the working fluid, methane, plays the role that water does on Earth. Titan's surface, with lakes and seas, broad river valleys, sand dunes and mountains was formed by processes like those that have shaped the Earth. Supporting this panoply of Earth-like processes is an ice crust that floats atop what might be a liquid water ocean. Furthermore, Titan is rich in very many different organic compounds—more so than any place in the solar system, except Earth. The Titan Saturn System Mission (TSSM) concept that followed the 2007 TandEM ESA CV proposal [2] and the 2007 Titan Explorer NASA Flagship study [3], was examined [4,5] and prioritized by NASA and ESA in February 2009 as a mission to follow the Europa Jupiter System Mission. The TSSM study, like others before it, again concluded that an orbiter, a montgolfiѐre hot-air balloon and a surface package (e.g. lake lander, Geosaucer (instrumented heat shield), …) are very high priority elements for any future mission to Titan. Such missions could be conceived as Flagship/Cosmic Vision L-Class or as individual smaller missions that could possibly fit within NASA's New Frontiers or ESA's Cosmic Vision M-Class budgets. As a result of a multitude of Titan mission studies, several mission concepts have been developed that potentially fit within various cost classes. Also, a clear blueprint has been laid out for early efforts critical toward reducing the risks inherent in such missions. The purpose of this paper is to provide a brief overview of potential Titan (and Enceladus) mission

The exploration of Titan with an orbiter and a lake probe

NASA Astrophysics Data System (ADS)

Mitri, Giuseppe; Coustenis, Athena; Fanchini, Gilbert; Hayes, Alex G.; Iess, Luciano; Khurana, Krishan; Lebreton, Jean-Pierre; Lopes, Rosaly M.; Lorenz, Ralph D.; Meriggiola, Rachele; Moriconi, Maria Luisa; Orosei, Roberto; Sotin, Christophe; Stofan, Ellen; Tobie, Gabriel; Tokano, Tetsuya; Tosi, Federico

2014-12-01

Fundamental questions involving the origin, evolution, and history of both Titan and the broader Saturnian system can be answered by exploring this satellite from an orbiter and also in situ. We present the science case for an exploration of Titan and one of its lakes from a dedicated orbiter and a lake probe. Observations from an orbit-platform can improve our understanding of Titan's geological processes, surface composition and atmospheric properties. Further, combined measurements of the gravity field, rotational dynamics and electromagnetic field can expand our understanding of the interior and evolution of Titan. An in situ exploration of Titan's lakes provides an unprecedented opportunity to understand the hydrocarbon cycle, investigate a natural laboratory for prebiotic chemistry and habitability potential, and study meteorological and marine processes in an exotic environment. We briefly discuss possible mission scenarios for a future exploration of Titan with an orbiter and a lake probe.

The magnetic geometry of Titan's induced magnetosphere

NASA Astrophysics Data System (ADS)

Bertucci, C.; Achilleos, N.; Dougherty, M. K.

2011-12-01

As a result of the virtual absence of an intrinsic field at Titan, an induced magnetosphere is formed from the direct interaction between its atmosphere and the plasma environment. Observations at unmagnetized objects such as comets, or planets like Venus and Mars, have shown that the orientation of the magnetic field within an induced magnetosphere is, on average, symmetric with respect to the plane generated by the upstream magnetic field and plasma velocity vectors. Analyses of Voyager and early Cassini magnetometer data around Titan confirm this feature. In this work, we study the efficiency of the background magnetic field-based 'draping coordinate system' (DRAP) introduced in Neubauer et al., [2006] to organize Cassini magnetometer (MAG) measurements within the induced magnetosphere of Titan for all the close flybys of the Prime Mission where MAG data is available. We find that, in general, DRAP coordinates are efficient in organizing the orientation of the draped magnetic field according to the pattern expected for an induced magnetosphere, suggesting that the same system could be used to spatially organize plasma measurements. Departures from this picture are likely related to non stationarity in the upstream flow, fossil fields and, induced currents within Titan's ionosphere and, probably, its interior. REFERENCES: Neubauer, F. M., et al. (2006). Titan's near magnetotail from magnetic field and electron plasma observations and modeling: Cassini flybys TA, TB, and T3. Journal of Geophysical Research, 111(A10), 1-15. doi: 10.1029/2006JA011676.

INVESTIGATIVE RESEARCH PROJECTS RELATED TO THE TOHOKU EARTHQUAKE (THE GREAT EAST JAPAN EARTHQUAKE) CONDUCTED IN FUKUSHIMA

PubMed Central

YAMAMOTO, TOSHIYUKI; HASHIMOTO, YASUHIRO; YOSHIDA, MASAYUKI; OHNO, KIKUO; OHTO, HITOSHI; ABE, MASAFUMI

2015-01-01

ABSTRACT Backgrounds: On March 11th 2011, the Tohoku region of Japan was struck by catastrophic disasters. Thousands of people were killed due to a magnitude 9.0 earthquake and its subsequent tsunami. Furthermore, a serious nuclear crisis occurred in Fukushima Prefecture as a result of the disasters, and an emergency evacuation was ordered to people living near the nuclear power plants. There was a lot of anxiety regarding lost families as well as the influences of radioactivity on the health of people and their children. Based on these urgent and uncertain situations, a number of research projects were developed at many institutes both inside and outside Fukushima. Methods: We herein report the investigative research projects related to the Tohoku Earthquake (The Great East Japan Earthquake) conducted after the disasters. The research projects were reviewed by the Institutional Review Board in Fukushima Medical University during the two years following the disasters. The research projects conducted in universities other than Fukushima Medical University were also examined using questionnaire analysis. Results: Among the research projects conducted in Fukushima Medical University (n=424), 7% (n=32) were disaster-related investigative research. The mean duration planned to pursue the projects was 25.5 months. Among these projects, those focusing on the health of Fukushima citizens were most common (n=9), followed by the influence of chronic exposure of radiation on chronic inflammatory disorders (n=6), and the mental health of Fukushima citizens (n=5). They were carefully reviewed for the purpose, suitability, and necessity from ethical as well as scientific viewpoints. The majority of the research projects focused on the effects of the Tohoku Earthquake and/or chronic exposure to low-dose radioactivity on the health of children and pregnant women, as well as on various disorders, such as mental health and chronic inflammatory diseases. On the other hand, among 58

INVESTIGATIVE RESEARCH PROJECTS RELATED TO THE TOHOKU EARTHQUAKE (THE GREAT EAST JAPAN EARTHQUAKE) CONDUCTED IN FUKUSHIMA.

PubMed

Yamamoto, Toshiyuki; Hashimoto, Yasuhiro; Yoshida, Masayuki; Ohno, Kikuo; Ohto, Hitoshi; Abe, Masafumi

2015-01-01

On March 11(th) 2011, the Tohoku region of Japan was struck by catastrophic disasters. Thousands of people were killed due to a magnitude 9.0 earthquake and its subsequent tsunami. Furthermore, a serious nuclear crisis occurred in Fukushima Prefecture as a result of the disasters, and an emergency evacuation was ordered to people living near the nuclear power plants. There was a lot of anxiety regarding lost families as well as the influences of radioactivity on the health of people and their children. Based on these urgent and uncertain situations, a number of research projects were developed at many institutes both inside and outside Fukushima. We herein report the investigative research projects related to the Tohoku Earthquake (The Great East Japan Earthquake) conducted after the disasters. The research projects were reviewed by the Institutional Review Board in Fukushima Medical University during the two years following the disasters. The research projects conducted in universities other than Fukushima Medical University were also examined using questionnaire analysis. Among the research projects conducted in Fukushima Medical University (n=424), 7% (n=32) were disaster-related investigative research. The mean duration planned to pursue the projects was 25.5 months. Among these projects, those focusing on the health of Fukushima citizens were most common (n=9), followed by the influence of chronic exposure of radiation on chronic inflammatory disorders (n=6), and the mental health of Fukushima citizens (n=5). They were carefully reviewed for the purpose, suitability, and necessity from ethical as well as scientific viewpoints. The majority of the research projects focused on the effects of the Tohoku Earthquake and/or chronic exposure to low-dose radioactivity on the health of children and pregnant women, as well as on various disorders, such as mental health and chronic inflammatory diseases. On the other hand, among 58 projects we collected from 22

Titan's Atmosphere and Surface Explored by Future in Situ Balloon Investigations

NASA Astrophysics Data System (ADS)

Coustenis, Athena; OPAG Titan Working Group

2009-09-01

A wide range of high priority scientific questions for Titan remain to be addressed after Cassini-Huygens, some of which cannot be comprehensively addressed by any envisioned extension of Cassini flybys due to its inherent limitations and require both remote and in situ investigation. Whereas a spacecraft in orbit around Titan could allow for a thorough investigation of Titan's upper atmosphere, there are questions that can only be answered by extending the measurements into Titan's lower atmosphere and down to the surface. Key steps toward the synthesis of prebiotic molecules that may have been present on the early Earth as precursors to life might be occurring high in the atmosphere, the products then descending towards the surface where they might replicate. In situ chemical analysis of gases, liquids and solids, both in the atmosphere and on the surface, would enable the identification of chemical species that are present and how far such putative reactions have advanced. The rich inventory of complex organic molecules that are known or suspected to be present in the lower atmosphere and at the surface gives Titan a strong astrobiological potential. Our understanding of the forces that shape Titan's diverse landscape and interior will benefit greatly from detailed investigations at a variety of locations, a demanding requirement anywhere else, but one that is uniquely possible at Titan using a hot-air balloon (montgolfière). Indeed, Titan's thick cold atmosphere and low gravity make the deployment of in situ elements using parachutes (as demonstrated by the Cassini-Huygens probe) and balloons vastly easier than for any other solar system body. A balloon floating across the Titan landscape for long periods of time, with an adapted payload, would offer the mobility required to explore the diversity of Titan in a way that cannot be achieved with any other platform.

Composition of Titan's surface from Cassini VIMS

USGS Publications Warehouse

McCord, T.B.; Hansen, G.B.; Buratti, B.J.; Clark, R.N.; Cruikshank, D.P.; D'Aversa, E.; Griffith, C.A.; Baines, E.K.H.; Brown, R.H.; Dalle, Ore C.M.; Filacchione, G.; Formisano, V.; Hibbitts, C.A.; Jaumann, R.; Lunine, J.I.; Nelson, R.M.; Sotin, Christophe

2006-01-01

Titan's bulk density along with Solar System formation models indicates considerable water as well as silicates as its major constituents. This satellite's dense atmosphere of nitrogen with methane is unique. Deposits or even oceans of organic compounds have been suggested to exist on Titan's solid surface due to UV-induced photochemistry in the atmosphere. Thus, the composition of the surface is a major piece of evidence needed to determine Titan's history. However, studies of the surface are hindered by the thick, absorbing, hazy and in some places cloudy atmosphere. Ground-based telescope investigations of the integral disk of Titan attempted to observe the surface albedo in spectral windows between methane absorptions by calculating and removing the haze effects. Their results were reported to be consistent with water ice on the surface that is contaminated with a small amount of dark material, perhaps organic material like tholin. We analyze here the recent Cassini Mission's visual and infrared mapping spectrometer (VIMS) observations that resolve regions on Titan. VIMS is able to see surface features and shows that there are spectral and therefore likely compositional units. By several methods, spectral albedo estimates within methane absorption windows between 0.75 and 5 ??m were obtained for different surface units using VIMS image cubes from the Cassini-Huygens Titan Ta encounter. Of the spots studied, there appears to be two compositional classes present that are associated with the lower albedo and the higher albedo materials, with some variety among the brighter regions. These were compared with spectra of several different candidate materials. Our results show that the spectrum of water ice contaminated with a darker material matches the reflectance of the lower albedo Titan regions if the spectral slope from 2.71 to 2.79 ??m in the poorly understood 2.8-??m methane window is ignored. The spectra for brighter regions are not matched by the spectrum of

Aerothermodynamic environment for a Titan probe with deployable decelerator

NASA Technical Reports Server (NTRS)

Green, M. J.; Swenson, B. L.; Balakrishnan, A.

1985-01-01

It is pointed out that further exploration of Titan, Saturn's largest moon, is of current interest to the scientific community, particularly from the standpoint of the organic chemical evolution of its atmosphere. For a suitable study of this Saturnian satellite, a mission involving a Titan atmospheric entry probe is to be conducted. The probe is to employ a deployable decelerator with the aim to allow scientific measurements in the haze layer. The present investigation is concerned with an assessment of the aerothermodynamic environment for the considered probe during its hypervelocity, low-Reynolds-number entry. Attention is given to the employed computational method, the Titan probe configuration, the Titan probe trajectory, the viscous-layer regime of the aerothermodynamic environment, and the incipient merged-layer regime.

Detailed exploration of Titan with a Montgolfiere aerobot

NASA Astrophysics Data System (ADS)

Spilker, T.; Tipex Team

The International Cassini/Huygens (CH) mission has verified the expectation that Saturn's moon Titan offers many opportunities for studying high-priority planetary and astrobiology science objectives. CH results to date show that this world, though entirely alien in its frigid environment, presents an Earth-like and diverse appearance due to the relative balance of competing forces such as geology/tectonics, meteorology, aeronomy, and cosmic impacts. But with the limitations of a single Huygens probe, and a finite number of Cassini flybys limited in proximity and remote sensing resolution by Titan's thick atmosphere and hazes, there is much science to be done there after the CH mission has ended. Detailed exploration of Titan's surface and lower atmosphere, especially for astrobiological objectives, is best addressed by in situ investigations. The atmosphere and its hazes severely restrict orbital remote sensing: Titan cannot be mapped from orbit in the same manner as Mars, at (essentially) arbitrarily high resolution, and limited infrared (IR) windows allow only gross compositional interpretations. After CH indeed there will be further orbital investigations to be carried out, notably completion of the global mapping by Synthetic Aperture Radar and IR mapping spectrometry begun by CH, at the best resolutions practical from orbit. But to fully understand Titan as an evolving, planetary-scale body and an abode of preserved protobiological chemistry will require a platform that has access to, and mobility at, the surface and the lowest few kilometers of the atmosphere. The TiPEx study team weighed the options for Titan in situ exploration, and finds that a mission based on a Montgolfiere (a type of hot-air balloon) aerobot is the best candidate for post-CH exploration. Ground-based platforms of the type used to date on Mars are far too limited in range to sample the diversity of Titan, and do not adequately investigate the lower atmosphere. Titan's cold, dense

Surface-Atmosphere Connections on Titan: A New Window into Terrestrial Hydroclimate

NASA Astrophysics Data System (ADS)

Faulk, Sean

This dissertation investigates the coupling between the large-scale atmospheric circulation and surface processes on Titan, with a particular focus on methane precipitation and its influence on surface geomorphology and hydrology. As the only body in the Solar System with an active hydrologic cycle other than Earth, Titan presents a valuable laboratory for studying principles of hydroclimate on terrestrial planets. Idealized general circulation models (GCMs) are used here to test hypotheses regarding Titan's surface-atmosphere connections. First, an Earth-like GCM simulated over a range of rotation rates is used to evaluate the effect of rotation rate on seasonal monsoon behavior. Slower rotation rates result in poleward migration of summer rain, indicating a large-scale atmospheric control on Titan's observed dichotomy of dry low latitudes and moist high latitudes. Second, a Titan GCM benchmarked against observations is used to analyze the magnitudes and frequencies of extreme methane rainstorms as simulated by the model. Regional patterns in these extreme events correlate well with observed geomorphic features, with the most extreme rainstorms occurring in mid-latitude regions associated with high alluvial fan concentrations. Finally, a planetary surface hydrology scheme is developed and incorporated into a Titan GCM to evaluate the roles of surface flow, subsurface flow, infiltration, and groundmethane evaporation in Titan's climate. The model reproduces Titan's observed surface liquid and cloud distributions, and reaches an equilibrium state with limited interhemispheric transport where atmospheric transport is approximately balanced by subsurface transport. The equilibrium state suggests that Titan's current hemispheric surface liquid asymmetry, favoring methane accumulation in the north, is stable in the modern climate.

Titan Airship Surveyor

NASA Technical Reports Server (NTRS)

Kerzhanovich, V.; Yavrouian, A.; Cutts, J.; Colozza, A.; Fairbrother, D.

2001-01-01

Saturn's moon Titan is considered to be one of the prime candidates for studying prebiotic materials - the substances that precede the formation of life but have disappeared from the Earth as a result of the evolution of life. A unique combination of a dense, predominantly nitrogen, atmosphere (more than four times that of the Earth), low gravity (six times less than on the Earth) and small temperature variations makes Titan the almost ideal planet for studies with lighter-than-air aerial platforms (aerobots). Moreover, since methane clouds and photochemical haze obscure the surface, low-altitude aerial platforms are the only practical means that can provide global mapping of the Titan surface at visible and infrared wavelengths. One major challenge in Titan exploration is the extremely cold atmosphere (approx. 90 K). However, current material technology the capability to operate aerobots at these very low temperatures. A second challenge is the remoteness from the Sun (10 AU) that makes the nuclear (radioisotopic) energy the only practical source of power. A third challenge is remoteness from the Earth (approx. 10 AU, two-way light-time approx. 160 min) which imposes restrictions on data rates and makes impractical any meaningful real-time control. A small-size airship (approx. 25 cu m) can carry a payload approximately 100 kg. A Stirling engine coupled to a radioisotope heat source would be the prime choice for producing both mechanical and electrical power for sensing, control, and communications. The cold atmospheric temperature makes Stirling machines especially effective. With the radioisotope power source the airship may fly with speed approximately 5 m/s for a year or more providing an excellent platform for in situ atmosphere measurements and a high-resolution remote sensing with unlimited access on a global scale. In a station-keeping mode the airship can be used for in situ studies on the surface by winching down an instrument package. Floating above the

Koreans in Japan: Their Influence on Korean-Japanese Relations.

DTIC Science & Technology

1979-09-01

1963. 31. The Republic of Korea National Red Cross, The Dispersed Families in Korea, Seoul, 1977. 32. Sato , Shoki, Koreans in Japan - The...1975. 34. Sumiya, Mikio , Kankoku no Keizai (The Korean Economy), Iwanami Shoten, Tokyo, Japan, 1974. 35. U.S. Government Printing Office, U.S. Army Area

C3 Hydrocarbon Abundance in Titan's Atmosphere with Cassini Infrared Spectra

NASA Astrophysics Data System (ADS)

Lombardo, Nicholas; Nixon, Conor; Achterberg, Richard; Jolly, Antoine; Sung, Keeyoon; Irwin, Patrick; Flasar, F. M.

2018-01-01

Titan, the largest moon of the Saturn system, has an astrobiologically important atmosphere. The anoxic nature and high N2 abundance make it a strong analog to the early Earth. The secondary species, CH4, is easily photodissociated, and reactions between its dissociated products give rise to highly complex hydrocarbons and nitriles. The Voyager flyby and 14 year Cassini campaign allowed for the intense study of several of these molecules, enabling scientists to increase our understanding of the chemical pathways present above Titan. In this work, we report abundance profiles of four major C3 gasses expected to occur in Titan’s atmosphere, derived from Cassini/Composite Infrared Spectrometer (CIRS) data, allowing us to fill the gaps in the photochemical zoo that is Titan’s atmosphere.Using the NEMESIS iterative radiative transfer module, we retrieved vertical abundance profiles for propane (C3H8) and propyne (CHCCH3) both initially detected by the Voyager IRIS instrument. Using newly available line data, we were also able to determine the first vertical abundance profiles for propene (C3H6), initially detected in 2013. We present profiles for several latitudes and times and compare to photochemical model predictions and previous observations. We also discuss our ongoing search for allene (CH2CCH2), an isomer of propyne, which has yet to be definitively detected. The abundances we determined will help to further our understanding of the chemical pathways that occur in Titan's atmosphere.

Cassini's Final Titan Radar Swath

NASA Image and Video Library

2017-08-11

During its final targeted flyby of Titan on April 22, 2017, Cassini's radar mapper got the mission's last close look at the moon's surface. On this 127th targeted pass by Titan (unintuitively named "T-126"), the radar was used to take two images of the surface, shown at left and right. Both images are about 200 miles (300 kilometers) in width, from top to bottom. Objects appear bright when they are tilted toward the spacecraft or have rough surfaces; smooth areas appear dark. At left are the same bright, hilly terrains and darker plains that Cassini imaged during its first radar pass of Titan, in 2004. Scientists do not see obvious evidence of changes in this terrain over the 13 years since the original observation. At right, the radar looked once more for Titan's mysterious "magic island" (PIA20021) in a portion of one of the large hydrocarbon seas, Ligeia Mare. No "island" feature was observed during this pass. Scientists continue to work on what the transient feature might have been, with waves and bubbles being two possibilities. In between the two parts of its imaging observation, the radar instrument switched to altimetry mode, in order to make a first-ever (and last-ever) measurement of the depths of some of the lakes that dot the north polar region. For the measurements, the spacecraft pointed its antenna straight down at the surface and the radar measured the time delay between echoes from the lakes' surface and bottom. A graph is available at https://photojournal.jpl.nasa.gov/catalog/PIA21626

Progressive Climate Change on Titan: Implications for Habitability

NASA Technical Reports Server (NTRS)

Moore, J. M.; A. D. Howard

2014-01-01

Titan's landscape is profoundly shaped by its atmosphere and comparable in magnitude perhaps with only the Earth and Mars amongst the worlds of the Solar System. Like the Earth, climate dictates the intensity and relative roles of fluvial and aeolian activity from place to place and over geologic time. Thus Titan's landscape is the record of climate change. We have investigated three broad classes of Titan climate evolution hypotheses (Steady State, Progressive, and Cyclic), regulated by the role, sources, and availability of methane. We favor the Progressive hypotheses, which we will outline here, then discuss their implication for habitability.

Engineering-Level Model Atmospheres for Titan and Neptune

NASA Technical Reports Server (NTRS)

Justus, C. G.; Duvall, Aleta; Johnson, D. L.

2003-01-01

Engineering-level atmospheric models for Titan and Neptune have been developed for use in NASA s systems analysis studies of aerocapture applications in missions to the outer planets. Analogous to highly successful Global Reference Atmospheric Models for Earth (GRAM, Justus et al., 2000) and Mars (Mars-GRAM, Justus and Johnson, 2001, Justus et al., 2002) the new models are called Titan-GRAM and Neptune-GRAM. Like GRAM and Mars-GRAM, an important feature of Titan-GRAM and Neptune-GRAM is their ability to simulate quasi-random perturbations for Monte- Carlo analyses in developing guidance, navigation and control algorithms, and for thermal systems design.

Decontamination of 2-chloroethyl ethylsulfide using titanate nanoscrolls

NASA Astrophysics Data System (ADS)

Kleinhammes, Alfred; Wagner, George W.; Kulkarni, Harsha; Jia, Yuanyuan; Zhang, Qi; Qin, Lu-Chang; Wu, Yue

2005-08-01

Titanate nanoscrolls, a recently discovered variant of TiO 2 nanocrystals, are tested as reactive sorbent for chemical warfare agent (CWA) decontamination. The large surface area of the uncapped tubules provides the desired rapid absorption of the contaminant while water molecules, intrinsic constituents of titanate nanoscrolls, provide the necessary chemistry for hydrolytic reaction. In this study the decomposition of 2-chloroethyl ethylsulfide (CEES), a simulant for the CWA mustard, was monitored using 13C NMR. The NMR spectra reveal reaction products as expected from the hydrolysis of CEES. This demonstrates that titanate nanoscrolls could potentially be employed as a decontaminant for CWAs.

Crater Topography on Titan: Implications for Landscape Evolution

NASA Technical Reports Server (NTRS)

Neish, Catherine D.; Kirk, R.L.; Lorenz, R. D.; Bray, V. J.; Schenk, P.; Stiles, B. W.; Turtle, E.; Mitchell, K.; Hayes, A.

2013-01-01

We present a comprehensive review of available crater topography measurements for Saturn's moon Titan. In general, the depths of Titan's craters are within the range of depths observed for similarly sized fresh craters on Ganymede, but several hundreds of meters shallower than Ganymede's average depth vs. diameter trend. Depth-to-diameter ratios are between 0.0012 +/- 0.0003 (for the largest crater studied, Menrva, D approximately 425 km) and 0.017 +/- 0.004 (for the smallest crater studied, Ksa, D approximately 39 km). When we evaluate the Anderson-Darling goodness-of-fit parameter, we find that there is less than a 10% probability that Titan's craters have a current depth distribution that is consistent with the depth distribution of fresh craters on Ganymede. There is, however, a much higher probability that the relative depths are uniformly distributed between 0 (fresh) and 1 (completely infilled). This distribution is consistent with an infilling process that is relatively constant with time, such as aeolian deposition. Assuming that Ganymede represents a close 'airless' analogue to Titan, the difference in depths represents the first quantitative measure of the amount of modification that has shaped Titan's surface, the only body in the outer Solar System with extensive surface-atmosphere exchange.

Titan Ion Composition at Magnetosphere-Ionosphere Transition Region

NASA Technical Reports Server (NTRS)

Sittler, Edward C.; Hartle, R. E.; Shappirio, M.; Simpson, D. J.; COoper, J. F.; Burger, M. H.; Johnson, R. E.; Bertucci, C.; Luhman, J. G.; Ledvina, S. A.;

Design of a Long Endurance Titan VTOL Vehicle

NASA Technical Reports Server (NTRS)

Prakash, Ravi; Braun, Robert D.; Colby, Luke S.; Francis, Scott R.; Guenduez, Mustafa E.; Flaherty, Kevin W.; Lafleur, Jarret M.; Wright, Henry S.

2006-01-01

Saturn s moon Titan promises insight into many key scientific questions, many of which can be investigated only by in situ exploration of the surface and atmosphere of the moon. This research presents a vertical takeoff and landing (VTOL) vehicle designed to conduct a scientific investigation of Titan s atmosphere, clouds, haze, surface, and any possible oceans. In this investigation, multiple options for vertical takeoff and horizontal mobility were considered. A helicopter was baselined because of its many advantages over other types of vehicles, namely access to hazardous terrain and the ability to perform low speed aerial surveys. Using a nuclear power source and the atmosphere of Titan, a turbo expander cycle produces the 1.9 kW required by the vehicle for flight and operations, allowing it to sustain a long range, long duration mission that could traverse the majority of Titan. Such a power source could increase the lifespan and quality of science for planetary aerial flight to an extent that the limiting factor for the mission life is not available power but the life of the mechanical parts. Therefore, the mission could potentially last for years. This design is the first to investigate the implications of this potentially revolutionary technology on a Titan aerial vehicle.

Radiation damage and nanocrystal formation in uranium-niobium titanates

NASA Astrophysics Data System (ADS)

Lian, J.; Wang, S. X.; Wang, L. M.; Ewing, R. C.

2001-07-01

Two uranium-niobium titanates, U 2.25Nb 1.90Ti 0.32O 9.8 and Nb 2.75U 1.20Ti 0.36O 10, formed during the synthesis of brannnerite (UTi 2O 6), a minor phase in titanate-based ceramics investigated for plutonium immobilization. These uranium titanates were subjected to 800 keV Kr 2+ irradiation from 30 to 973 K. The critical amorphization dose of the U-rich and Nb-rich titanates at room temperature were 4.72×10 17 and 5×10 17 ions/ m2, respectively. At elevated temperature, the critical amorphization dose increases due to dynamic thermal annealing. The critical amorphization temperature for both Nb-rich and U-rich titanates is ˜933 K under a 800 keV Kr 2+ irradiation. Above the critical amorphization temperature, nanocrystals with an average size of ˜15 nm were observed. The formation of nanocrystals is due to epitaxial recrystallization. At higher temperatures, an ion irradiation-induced nucleation-growth mechanism also contributes to the formation of nanocrystals.

The Titan Haze Simulation Experiment: Latest Laboratory Results and Dedicated Plasma Chemistry Model

NASA Astrophysics Data System (ADS)

Sciamma-O'Brien, Ella; Raymond, Alexander; Mazur, Eric; Salama, Farid

2017-06-01

In Titan’s atmosphere, a complex organic chemistry occurs between its main constituents, N2 and CH4, and leads to the production of larger molecules and solid aerosols.Here, we present the latest results on the gas and solid phase analyses in the Titan Haze Simulation (THS) experiment, developed on the NASA Ames COSmIC simulation chamber. The THS is a unique experimental platform that allows us to simulate Titan’s atmospheric chemistry at Titan-like temperature (200K) by cooling down N2-CH4-based mixtures in a supersonic expansion before inducing the chemistry by plasma. Because of the accelerated gas flow in the expansion, the residence time of the gas in the active plasma region is less than 3 µs. This results in a truncated chemistry that enables us to monitor the first and intermediate steps of the chemistry as well as specific chemical pathways when adding, in the initial gas mixture, heavier molecules that have been detected as trace elements on Titan[1].We discuss the results of recent Mid-infrared (MIR) spectroscopy[2] and X-ray Absorption Near Edge Structure spectroscopy studies of THS Titan tholins produced in different gas mixtures (with and without acetylene and benzene). Both studies have shown the presence of nitrogen chemistry, and differences in the level and nature of the nitrogen incorporation depending on the initial gas mixture. A comparison of THS MIR spectra to VIMS data has shown that the THS aerosols produced in simpler mixtures, i.e., that contain more nitrogen and where the N-incorporation is in isocyanide-type molecules instead of nitriles, are more representative of Titan’s aerosols.In addition, a new model has been developed to simulate the plasma chemistry in the THS. Electron impact and chemical kinetics equations for more than 120 species are followed. The calculated mass spectra are in good agreement with the experimental THS mass spectra[1], confirming that the short residence time in the plasma cavity limits the growth of

The Titan Haze Simulation Experiment: Latest Laboratory Results and Dedicated Plasma Chemistry Model

NASA Astrophysics Data System (ADS)

Sciamma-O'Brien, Ella; Raymond, Alexander; Mazur, Eric; Salama, Farid

2017-10-01

Here, we present the latest results on the gas- and solid phase analyses in the Titan Haze Simulation (THS) experiment, developed at the NASA Ames COSmIC simulation chamber. The THS is a unique experimental platform that allows us to simulate Titan’s complex atmospheric chemistry at Titan-like temperature (200 K) by cooling down N2-CH4-based mixtures in a supersonic expansion before inducing the chemistry by plasma. Because of the accelerated gas flow in the expansion, the residence time of the gas in the active plasma region is less than 3 µs. This results in a truncated chemistry that enables us to control how far in the chain of chemical reactions chemistry processes[1], by adding, in the initial gas mixture, heavier molecules that have been detected as trace elements on Titan.We discuss the results of recent Mid-infrared (MIR) spectroscopy[2] and X-ray Absorption Near Edge Structure spectroscopy studies of THS Titan tholins produced in different gas mixtures (with and without acetylene and benzene). Both studies have shown the presence of nitrogen chemistry, and differences in the level and nature of the nitrogen incorporation depending on the initial gas mixture. A comparison of THS MIR spectra to VIMS data has shown that the THS aerosols produced in simpler mixtures, i.e., that contain more nitrogen and where the N-incorporation is in isocyanide-type molecules instead of nitriles, are more representative of Titan’s aerosols.In addition, a new model has been developed to simulate the plasma chemistry in the THS. Electron impact and chemical kinetics equations for more than 120 species are followed. The calculated mass spectra[3] are in good agreement with the experimental THS mass spectra[1], confirming that the short residence time in the plasma cavity limits the growth of larger species and results in a truncated chemistry, a main feature of the THS.References:[1] Sciamma-O'Brien E. et al., Icarus, 243, 325 (2014)[2] Sciamma-O'Brien E. et al., Icarus

Huygens Titan Probe Trajectory Reconstruction Using Traditional Methods and the Program to Optimize Simulated Trajectories II

NASA Technical Reports Server (NTRS)

Striepe, Scott A.; Blanchard, Robert C.; Kirsch, Michael F.; Fowler, Wallace T.

2007-01-01

On January 14, 2005, ESA's Huygens probe separated from NASA's Cassini spacecraft, entered the Titan atmosphere and landed on its surface. As part of NASA Engineering Safety Center Independent Technical Assessment of the Huygens entry, descent, and landing, and an agreement with ESA, NASA provided results of all EDL analyses and associated findings to the Huygens project team prior to probe entry. In return, NASA was provided the flight data from the probe so that trajectory reconstruction could be done and simulation models assessed. Trajectory reconstruction of the Huygens entry probe at Titan was accomplished using two independent approaches: a traditional method and a POST2-based method. Results from both approaches are discussed in this paper.

Heavy Ion Formation in Titan's Ionosphere: Magnetospheric Introduction of Free Oxygen and a Source of Titan's Aerosols?

NASA Technical Reports Server (NTRS)

Sittler, E. C., Jr.; Ali, A.; Cooper, J. F.; Hartle, R. E.; Johnson, R. E.; Coates, A. J.; Young, D. T.

2009-01-01

Discovery by Cassini's plasma instrument of heavy positive and negative ions within Titan's upper atmosphere and ionosphere has advanced our understanding of ion neutral chemistry within Titan's upper atmosphere, primarily composed of molecular nitrogen, with approx.2.5% methane. The external energy flux transforms Titan's upper atmosphere and ionosphere into a medium rich in complex hydrocarbons, nitriles and haze particles extending from the surface to 1200 km altitudes. The energy sources are solar UV, solar X-rays, Saturn's magnetospheric ions and electrons, solar wind and shocked magnetosheath ions and electrons, galactic cosmic rays (CCR) and the ablation of incident meteoritic dust from Enceladus' E-ring and interplanetary medium. Here it is proposed that the heavy atmospheric ions detected in situ by Cassini for heights >950 km, are the likely seed particles for aerosols detected by the Huygens probe for altitudes <100km. These seed particles may be in the form of polycyclic aromatic hydrocarbons (PAH) containing both carbon and hydrogen atoms CnHx. There could also be hollow shells of carbon atoms, such as C60, called fullerenes which contain no hydrogen. The fullerenes may compose a significant fraction of the seed particles with PAHs contributing the rest. As shown by Cassini, the upper atmosphere is bombarded by magnetospheric plasma composed of protons, H(2+) and water group ions. The latter provide keV oxygen, hydroxyl and water ions to Titan's upper atmosphere and can become trapped within the fullerene molecules and ions. Pickup keV N(2+), N(+) and CH(4+) can also be implanted inside of fullerenes. Attachment of oxygen ions to PAH molecules is uncertain, but following thermalization O(+) can interact with abundant CH4 contributing to the CO and CO2 observed in Titan's atmosphere. If an exogenic keV O(+) ion is implanted into the haze particles, it could become free oxygen within those aerosols that eventually fall onto Titan's surface. The process

Titan's Stratospheric Condensibles at High Northern Latitudes During Northern Winter

NASA Technical Reports Server (NTRS)

Anderson, Carrie; Samuelson, R.; Achterberg, R.

2012-01-01

The Infrared Interferometer Spectrometer (IRIS) instrument on board Voyager 1 caught the first glimpse of an unidentified particulate feature in Titan's stratosphere that spectrally peaks at 221 per centimeter. Until recently, this feature that we have termed 'the haystack,' has been seen persistently at high northern latitudes with the Composite Infrared Spectrometer (CIRS) instrument onboard Cassini, The strength of the haystack emission feature diminishes rapidly with season, becoming drastically reduced at high northern latitudes, as Titan transitions from northern winter into spring, In contrast to IRIS whose shortest wavenumber was 200 per centimeter, CIRS extends down to 10 per centimeter, thus revealing an entirely unexplored spectral region in which nitrile ices have numerous broad lattice vibration features, Unlike the haystack, which is only found at high northern latitudes during northern winter/early northern spring, this geometrically thin nitrile cloud pervades Titan's lower stratosphere, spectrally peaking at 160 per centimeter, and is almost global in extent spanning latitudes 85 N to 600 S, The inference of nitrile ices are consistent with the highly restricted altitude ranges over which these features are observed, and appear to be dominated by a mixture of HCN and HC3N, The narrow range in altitude over which the nitrile ices extend is unlike the haystack, whose vertical distribution is significantly broader, spanning roughly 70 kilometers in altitude in Titan's lower stratosphere, The nitrile clouds that CIRS observes are located in a dynamically stable region of Titan's atmosphere, whereas CH4 clouds, which ordinarily form in the troposphere, form in a more dynamically unstable region, where convective cloud systems tend to occur. In the unusual situation where Titan's tropopause cools significantly from the HASI 70.5K temperature minimum, CH4 should condense in Titan's lower stratosphere, just like the aforementioned nitrile clouds, although

Poster 17: Methane storms as a driver of Titan's dune orientation.

NASA Astrophysics Data System (ADS)

Charnay, Benjamin; Barth, Erika; Rafkin, Scot; Narteau, Clement; Lebonnois, Sebastien; Rodriguez, Sebastien; Courech Du Pont, Sylvain; Lucas, Antoine

2016-06-01

Titan's equatorial regions are covered by eastward oriented linear dunes [1,2]. This direction is opposite to mean surface winds simulated by Global Climate Models (GCMs) at these latitudes, oriented westward as trade winds on Earth. We propose that Titan's dune orientation is actually determined by equinoctial tropical methane storms producing a coupling with superrotation and dune formation [3]. Using meso-scale simulations of convective methane clouds [4] with a GCM wind profile featuring the superrotation [5,6], we show that Titan's storms should produce fast eastward gust fronts above the surface. Such gusts dominate the aeolian transport. Using GCM wind calculations and analogies with terrestrial dune fields [7], we show that Titan's dune propagation occurs eastward under these conditions. Finally, this scenario combining global circulation winds and methane storms can explain other major features of Titan's dunes as the divergence from the equator or the dune size and spacing. It also implies an equatorial origin of Titan's dune sand and a possible occurence of dust storms.

Variations in Rotation Rate and Polar Motion of a Non-hydrostatic Titan

NASA Astrophysics Data System (ADS)

Van Hoolst, T.; Coyette, A.; Baland, R. M.

2017-12-01

Observations of the rotation of large synchronously rotating satellites such as Titan can help to probe their interior. Previous studies (Van Hoolst et al. 2013, Richard et al. 2014, Coyette et al. 2016) mostly assume that Titan is in hydrostatic equilibrium, although several measurements indicate that it deviates from such a state. Here we investigate the effect of non-hydrostatic equilibrium and of flow in the subsurface ocean on the rotation of Titan. We consider (1) the periodic changes in Titan's rotation rate with a period equal to Titan's orbital period (diurnal librations) as a result of the gravitational torque exerted by Saturn, (2) the periodic changes in Titan's rotation rate with a main period equal to half the orbital period of Saturn (seasonal librations) and due to the dynamic variations in the atmosphere of Titan and (3) the periodic changes of the axis of rotation with respect to the figure axis of Titan (polar motion) with a main period equal to the orbital period of Saturn and due to the dynamic variations in the atmosphere of Titan. The non-hydrostatic mass distribution significantly influences the amplitude of the diurnal and seasonal librations. It is less important for polar motion, which is sensitive to flow in the subsurface ocean. The smaller than synchronous rotation rate measured by Cassini (Meriggiola 2016) can be explained by the atmospheric forcing.

Titan's 5 micrometers spectral window: carbon monoxide and the albedo of the surface

NASA Technical Reports Server (NTRS)

Noll, K. S.; Geballe, T. R.; Knacke, R. F.; Pendleton, Y. J.

1996-01-01

We have measured the spectrum of Titan near 5 micrometers and have found it to be dominated by absorption from the carbon monoxide 1-0 vibration-rotation band. The position of the band edge allows us to constrain the abundance of CO in the atmosphere and/or the location of the reflecting layer in the atmosphere. In the most likely case, 5 micrometers radiation is reflected from the surface and the mole fraction of CO in the atmosphere is qCO=10(+10/-5) ppm, significantly lower than previous estimates for tropospheric CO. The albedo of the reflecting layer is approximately 0.07(+0.02/-0.01) in the 5 micrometers continuum outside the CO band. The 5 micrometers albedo is consistent with a surface of mixed ice and silicates similar to the icy Galilean satellites. Organic solids formed in simulated Titan conditions can also produce similar albedos at 5 micrometers.

Japanese-U.S. Economic Relations. Japan Digest.

ERIC Educational Resources Information Center

Ellington, Lucien

World War II was the last time when overall U.S.-Japan relations, and the economic relationship in particular, were as bad as appears to be the case in the 1990s. The United States and Japan are, respectively, the two largest economies in the world. The Japanese have the second leading market for U.S. products trailing only Canada. Japan buys more…

Between heaven and Earth: the exploration of Titan.

PubMed

Owen, Tobias C; Niemann, Hasso; Atreya, Sushil; Zolotov, Mikhail Y

2006-01-01

The atmosphere of Titan represents a bridge between the early solar nebula and atmospheres like ours. The low abundances of primordial noble gases in Titan's atmosphere relative to N2 suggest that the icy planetesimals that formed the satellite must have originated at temperatures higher than 75-100 K. Under these conditions, N2 would also be very poorly trapped and thus Titan's nitrogen, like ours, must have arrived as nitrogen compounds, of which ammonia was likely the major component. This temperature constraint also argues against the trapping of methane. Production of this gas on the satellite after formation appears reasonable based on terrestrial examples of serpentinization, disproportionation and reduction of carbon. These processes require rocks, water, suitable catalysts and the variety of primordial carbon compounds that were plausibly trapped in Titan's ices. Application of this same general scenario to Ganymede, Callisto, KBOs and conditions on the very early Earth seems promising.

RADAR Reveals Titan Topography

NASA Technical Reports Server (NTRS)

Kirk, R. L.; Callahan, P.; Seu, R.; Lorenz, R. D.; Paganelli, F.; Lopes, R.; Elachi, C.

2005-01-01

The Cassini Titan RADAR Mapper is a K(sub u)-band (13.78 GHz, lambda = 2.17 cm) linear polarized RADAR instrument capable of operating in synthetic aperture (SAR), scatterometer, altimeter and radiometer modes. During the first targeted flyby of Titan on 26 October, 2004 (referred to as Ta) observations were made in all modes. Evidence for topographic relief based on the Ta altimetry and SAR data are presented here. Additional SAR and altimetry observations are planned for the T3 encounter on 15 February, 2005, but have not been carried out at this writing. Results from the T3 encounter relevant to topography will be included in our presentation. Data obtained in the Ta encounter include a SAR image swath

TandEM: Titan and Enceladus mission

USGS Publications Warehouse

Coustenis, A.; Atreya, S.K.; Balint, T.; Brown, R.H.; Dougherty, M.K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R.A.; Griffith, C.A.; Gurvits, L.I.; Jaumann, R.; Langevin, Y.; Leese, M.R.; Lunine, J.I.; McKay, C.P.; Moussas, X.; Muller-Wodarg, I.; Neubauer, F.; Owen, T.C.; Raulin, F.; Sittler, E.C.; Sohl, F.; Sotin, Christophe; Tobie, G.; Tokano, T.; Turtle, E.P.; Wahlund, J.-E.; Waite, J.H.; Baines, K.H.; Blamont, J.; Coates, A.J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R.D.; Morse, A.; Porco, C.C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J.C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D.H.; Benilan, Y.; Bertucci, C.; Bezard, B.; Bjoraker, G.L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M.T.; Chassefiere, E.; Coll, P.; Combes, M.; Cooper, J.F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I.A.; de Angelis, E.; De Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F.M.; Fortes, A.D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Kuppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le, Mouelic S.; Lebonnois, S.; Ledvina, S.; Li, Ji; Livengood, T.A.; Lopes, R.M.; Lopez-Moreno, J. -J.; Luz, D.; Mahaffy, P.R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Salvan, C.M.; Milillo, A.; Mitchell, D.G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, Catherine D.; Nixon, C.A.; Mvondo, D.N.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F.T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Bermejo, M.R.; Sarris, E.T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L.J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D.F.; Szego, K.; Szopa,

2009-01-01

TandEM was proposed as an L-class (large) mission in response to ESA’s Cosmic Vision 2015–2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini–Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini–Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfière) and possibly several landing probes to be delivered through the atmosphere.

TandEM: Titan and Enceladus mission

NASA Astrophysics Data System (ADS)

Coustenis, A.; Atreya, S. K.; Balint, T.; Brown, R. H.; Dougherty, M. K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R. A.; Griffith, C. A.; Gurvits, L. I.; Jaumann, R.; Langevin, Y.; Leese, M. R.; Lunine, J. I.; McKay, C. P.; Moussas, X.; Müller-Wodarg, I.; Neubauer, F.; Owen, T. C.; Raulin, F.; Sittler, E. C.; Sohl, F.; Sotin, C.; Tobie, G.; Tokano, T.; Turtle, E. P.; Wahlund, J.-E.; Waite, J. H.; Baines, K. H.; Blamont, J.; Coates, A. J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R. D.; Morse, A.; Porco, C. C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J. C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D. H.; Bénilan, Y.; Bertucci, C.; Bézard, B.; Bjoraker, G. L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M. T.; Chassefière, E.; Coll, P.; Combes, M.; Cooper, J. F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I. A.; de Angelis, E.; de Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F. M.; Fortes, A. D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Küppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le Mouélic, S.; Lebonnois, S.; Ledvina, S.; Li, J.; Livengood, T. A.; Lopes, R. M.; Lopez-Moreno, J.-J.; Luz, D.; Mahaffy, P. R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Menor Salvan, C.; Milillo, A.; Mitchell, D. G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, C. D.; Nixon, C. A.; Nna Mvondo, D.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F. T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Ruiz Bermejo, M.; Sarris, E. T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L. J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D. F.; Szego, K.; Szopa, C.; Thissen, R.; Tomasko, M. G.; Toublanc, D.; Vali, H.; Vardavas, I.; Vuitton, V.; West, R. A.; Yelle, R.; Young, E. F.

2009-03-01

TandEM was proposed as an L-class (large) mission in response to ESA’s Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfière) and possibly several landing probes to be delivered through the atmosphere.

Above Titan South

NASA Image and Video Library

2012-09-17

Titan south polar vortex seems to float above the moon south pole in this Cassini spacecraft view. The vortex, which is a mass of gas swirling around the south pole high in the moon atmosphere, can be seen in the lower right of this view.

Organic matter in the Titan lakes, and comparison with primitive Earth

NASA Astrophysics Data System (ADS)