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Jun 9, 2011
06/11
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Namkung, M.; Wincheski, B.; Fulton, J. P.; Todhunter, R. G
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An extensive study of magnetoacoustic emission (MAE) properties has been performed over the past several years. As a result, the dependence of the spectral characteristics of MAE on certain microstructural variations and uniaxially applied stress in a particular type of low carbon steel are now well known. The embrittlement-causing concentration of certain atomic species, e. g., tin, sulphur, phosphorous etc., at the grain boundaries of this steel creates strong potential barriers resisting the...
Topics: SOLAR ELECTRIC PROPULSION, GRAVITATIONAL EFFECTS, GAS GIANT PLANETS, GRAVITATION, TRAJECTORIES,...
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389
May 29, 2011
05/11
by
Miller, Phil; Coleman, Jason; Gemoets, Darren; Hughes, Kevi
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This paper describes Web-Altairis, an Internet-enabled ground system software package funded by the Advanced Automation and Architectures Branch (Code 588) of NASA's Goddard Space Flight Center. Web-Altairis supports the trend towards ''lights out'' ground systems, where the control center is unattended and problems are resolved by remote operators. This client/server software runs on most popular platforms and provides for remote data visualization using the rich functionality of the VisAGE...
Topics: INTERFEROMETERS, TELESCOPES, ASTRONOMICAL INTERFEROMETRY, EXTRASOLAR PLANETS, COSMIC DUST,...
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May 30, 2011
05/11
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Caimi, Raoul E.; Margashayam, Ravi N.; Nayfeh, Jamal F
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Rocket-induced vibration and ignition overpressure response environments are predicted in the low-frequency (5 to 200 hertz) range. The predictions are necessary to evaluate their impact on critical components, structures, and facilities in the immediate vicinity of the rocket launch pad.
Topics: ASTROPHYSICS, PLANETARY EVOLUTION, PROTOPLANETARY DISKS, PROTOSTARS, GAS GIANT PLANETS, CIRCULAR...
As we move into an era when GPI and SPHERE are (hopefully) discovering and characterizing new young giant planets, it is worthwhile to step back and review our science goals for young giant planets. Of course for individual planets we ideally would hope to measure mass, radius, atmospheric composition, temperature, and cloud properties, but how do these characteristics fit into our broader understanding of planetary system origin and evolution theories? In my presentation I will review both the...
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, PLANETARY SYSTEMS, PLANETARY EVOLUTION,...
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Sep 20, 2010
09/10
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Dill, Robert P.; Brown, N.; Curtis, R. L.; Herrmann, C. R.; Trampus, A
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The results of a reliability prediction study of the propulsion systems for the MSFC Saturn 5 Vehicle are presented. The TEMPO method of combining the failure mode of each component of the subsystems being analyzed was used throughout the study. Since most of the configurations of the subsystems examined are presently in the development phase, this prediction is based upon the current available data and should be considered a preliminary estimate only.
Topics: GAS GIANT PLANETS, LAUNCHING, PIONEER 10 SPACE PROBE, SPACECRAFT DESIGN, SPACECRAFT PERFORMANCE,...
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332
Jun 12, 2011
06/11
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Ip, Felipe; Sherwood, R; Dohm, J. M.; Baker, V. R.; Castano, B.; Chien, S.; Cichy, B.; Davies, A. G.; Doggett, T.; Greeley, R.
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NASA's New Millennium Program (NMP) Autonomous Sciencecraft Experiment (ASE) [1-3] has been successfully demonstrated in Earth-orbit. NASA has identified the development of an autonomously operating spacecraft as a necessity for an expanded program of missions exploring the Solar System. The versatile ASE spacecraft command and control, image formation, and science processing software was uploaded to the Earth Observer 1 (EO-1) spacecraft in early 2004 and has been undergoing onboard testing...
Topics: GAS GIANT PLANETS, NEBULAE, PROTOPLANETARY DISKS, WATER VAPOR, PLANETARY EVOLUTION, WATER, A STARS,...
Outline a step-by-step Development Plan of the key barriers and their solutions to enable human exploration of the outer solar system. Secondary: Perform a case study which supports and emphasizes the key elements of the Development Plan.
Topics: NASA Technical Reports Server (NTRS), SPACE EXPLORATION, GAS GIANT PLANETS, SOLAR SYSTEM, TITAN,...
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Jun 12, 2011
06/11
by
Colson, R. O.; Malum, K. M
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Understanding variations in activity with composition is an essential step in improving prediction of partition coefficients during magma evolution. Variations in activity with composition are complex and do not generally exhibit ideal behavior relative to a traditional melt-component set. Although deviations from component ideality can be modeled numerically by simply fitting to compositional variables (such as in a regular or subregular solution model), such models have not been particularly...
Topics: INTERPLANETARY DUST, ROCKS, HIGH TEMPERATURE, PLANETARY EVOLUTION, TRACE ELEMENTS, CHONDRITES,...
The research supported by this grant has focused on isotopic ratios in comets and in the atmosphere of Titan, and the determinations of surface compositions of outer solar system bodies.
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, ISOTOPES, TITAN, COMETS, SPECTROSCOPY,...
The Principal Investigator's responsibilities on this grant fell into two categories according to his participation. In the nomenclature work of the International Astronomical Union (IAU). Owen is chair of the Task Group for the Outer Solar System. He is also a member of the IAU's Working Group on Planetary and Satellite Nomenclature (WGPSN) which is composed of the chairs of the several Task Groups plus the presidents of two IAU Commissions and several outside consultants. The WGPSN is...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMY, ASTROPHYSICS, GAS GIANT PLANETS, SOLAR SYSTEM,...
Have you ever wondered about the science goals of various deep space missions? Or why scientists want such seemingly complicated spacecraft and operations scenarios? With a focus on outer planets) this talk will cover the scientific goals and results of several recent and future missions) how scientists approach a requirements flow down) and how the disparate needs of mission engineers and scientists can come together for mission success. It will also touch on several up and coming technologies...
Topics: NASA Technical Reports Server (NTRS), DEEP SPACE, AEROSPACE SCIENCES, GAS GIANT PLANETS, SPACE...
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386
Jun 12, 2011
06/11
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Lawson, Anthony L.; Parthasarathy, Ramkumar N
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It has been observed in previous experimental studies that round helium jets injected into air display a repetitive structure for a long distance, somewhat similar to the buoyancy-induced flickering observed in diffusion flames. In order to investigate the influence of gravity on the near-injector development of the flow, a linear temporal stability analysis of a round helium jet injected into air was performed. The flow was assumed to be isothermal and locally parallel; viscous and diffusive...
Topics: ELECTRIC PROPULSION, NUCLEAR ELECTRIC PROPULSION, CHEMICAL PROPULSION, SOLAR GENERATORS, NUCLEAR...
The goal of the project was to identify a statistically significant sample of large (200 km-sized) Kuiper Belt Objects (KBOs), by covering 10 sq. degrees of the sky to a red limiting magnitude m(sub R) = 23. This work differs from, but builds on, previous surveys of the outer solar system in that it will cover a large area to a limiting magnitude that is deep enough to guarantee positive results. The proposed work should provide us with a significant number of 200 km-size KBOs (approx. 20 are...
Topics: NASA Technical Reports Server (NTRS), STATISTICAL DISTRIBUTIONS, COMETS, KUIPER BELT, SURVEYS,...
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May 31, 2011
05/11
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Wercinski, Paul; Munk, Michelle; Powell, Richard; Hall, Jeff; Graves, Claud
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The purpose of this white paper is to identify aerocapture technology and system level development needs to enable NASA future mission planning to support Outer Planet Exploration. Aerocapture is a flight maneuver that takes place at very high speeds within a planet's atmosphere that provides a change in velocity using aerodynamic forces (in contrast to propulsive thrust) for orbit insertion. Aerocapture is very much a system level technology where individual disciplines such as system analysis...
Topics: SOLAR CELLS, SPACE MISSIONS, SPACE EXPLORATION, EARTH ORBITS, MISSION PLANNING, THIN FILMS, HIGH...
Surveys by ground based telescopes, HST, and Spitzer have revealed that brown dwarfs of most spectral classes exhibit variability. The spectral and temporal signatures of the variability are complex and apparently defy simplistic classification which complicates efforts to model the changes. Important questions include understanding if clearings are forming in an otherwise uniform cloud deck or if thermal perturbations, perhaps associated with breaking gravity waves, are responsible. If clouds...
Topics: NASA Technical Reports Server (NTRS), BROWN DWARF STARS, VARIABILITY, STELLAR ATMOSPHERES,...
This is a presentation about the Keck Interferometer which is being constructed on top of Mauna Kea, Hawaii. This includes using the world's largest telescopes for optical and near-infrared astronomy, the twin 10 meter Keck telescopes. The two Keck telescopes, in conjunction with four proposed outrigger telescopes, will be used as an interferometer to conduct observations as part of NASA's Origins Program. These observations will address a variety of topics, including the origin and evolution...
Topics: NASA Technical Reports Server (NTRS), INTERFEROMETERS, TELESCOPES, ASTRONOMICAL INTERFEROMETRY,...
The criteria for a habitable world initially was based on Earth and centered around liquid water on the surface, warmed by a Sun-like star. The moons of the outer Solar System, principally Europa and Enceladus, have demonstrated that liquid water can exist below the surface warmed by tidal forces from a giant planet. Titan demonstrates that surface liquids other than water - liquid methane/ethane - may be common on other worlds. Considering the numerous extrasolar planets so far discovered and...
Topics: NASA Technical Reports Server (NTRS), HABITABILITY, EXTRASOLAR PLANETS, EXPLORATION, WATER,...
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May 23, 2011
05/11
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Pulkkinen, T. I.; Mukai, T.; Nakamura, R.; Blake, J. B.; Russell, C. T.; Kawano, H.; Mozer, F.; Slavin, J. A; Baker, D. N.; Turner, N. E.; Singer, H. J.; Frank, L. A.; Sigwarth, J. B.; Scudder, J.; Anderson, R.; Kokubun, S.
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Multispacecraft data from the upstream solar wind, polar cusp, and inner magnetotail are used to show that the polar ionosphere responds within a few minutes to a southward IMF turning, whereas the inner tail signatures are visible within ten min from the southward turning. Comparison of two subsequent substorm onsets, one during southward and the other during northward IMF, demonstrates the dependence of the expansion phase characteristics on the external driving conditions. Both onsets are...
Topics: SURFACE ROUGHNESS EFFECTS, REFRACTIVITY, REMOTE SENSING, GREENHOUSE EFFECT, GAS GIANT PLANETS,...
Presented by Lissauer et al. (2009, Icarus 199, 338) are used to test the model of capture of Jupiter's irregular satellites within proto-Jupiter's distended and thermally-supported envelope. We find such capture highly unlikely, since the envelope shrinks too slowly for a large number of moons to be retained, and many of those that would be retained would orbit closer to the planet than do the observed Jovian irregulars. Our calculations do not address (and therefore do not exclude) the...
Topics: NASA Technical Reports Server (NTRS), SIMULATION, JUPITER (PLANET), JUPITER SATELLITES, GAS GIANT...
The rheologic properties of terrestrial lavas have been related to morphologic features of their flows, such as levees, banked surfaces, multilobate structures, and compressible folds. These features also have been used to determine rheologies and constrain the compositions of extraterrestrial flows. However, with rare exceptions, such features are not resolvable in Voyager images of the satellites of outer planets. Often only flow length and edge thickness of cryovolcanic flows can be measured...
Topics: NASA Technical Reports Server (NTRS), ICY SATELLITES, LAVA, LIQUIDUS, RHEOLOGY, SATELLITE SURFACES,...
This grant report highlights activity in the following areas: (1) Improvement in Precise Radial Velocity (PRV) analysis code; (2) Reanalysis of previous data; (3) Improvements to the AFOE (Advanced Fiber Optic Echelle) spectrograph; (4) Development of PRV capabilities for the Hectochelle; (5) Extra-solar planet studies; (6) Longer-term plans for the AFOE; (7) Completion and publication of the analysis of the transiting gas-giant planet HD 209458b.
Topics: NASA Technical Reports Server (NTRS), EXTRASOLAR PLANETS, GAS GIANT PLANETS, DETECTION,...
Under the support of NASA Origins grant, we studied the formation of gaps in protoplanetary disks due the tidal interaction between a fully grown protoplanet and protostellar disk. The result of this study is published in the Astrophysical Journal, (vol 514, 344-367, 1999) and in several conference proceedings. The main focus of this work is to analyze planet-disk interaction during the final stages of protoplanetary formation.
Topics: NASA Technical Reports Server (NTRS), ASTROPHYSICS, PLANETARY EVOLUTION, PROTOPLANETARY DISKS,...
Flagship mission for spectroscopy of ExoEarths is a long-term priority for space astrophysics (Astro2010). Requires 10(exp 10) contrast at 3 lambda/D separation, ( (is) greater than 10,000 times beyond HST performance) and large telescope (is) greater than 4m aperture. Big step. Mission for spectroscopy of giant planets and imaging of disks requires 10(exp 9) contrast at 3 lambda/D (already demonstrated in lab) and (is) approximately 1.5m telescope. Should be much more affordable, good...
Topics: NASA Technical Reports Server (NTRS), EXTRASOLAR PLANETS, IMAGING TECHNIQUES, CORONAGRAPHS,...
According to the prevailing core instability model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Models predict that rocky planets should form in orbit about most stars. It is uncertain whether or not gas giant planet formation is common, because...
Topics: NASA Technical Reports Server (NTRS), BROWN DWARF STARS, GAS GIANT PLANETS, PLANETARY EVOLUTION,...
Given our presently inadequate understanding of the turbulent state of the solar and planetary nebulae, we believe the way to make progress in satellite formation is to consider two end member models that avoid over-reliance on specific choices of the turbulence (alpha), which is essentially a free parameter. The first end member model postulates turbulence decay once giant planet accretion ends. If so, Keplerian disks must eventually pass through the quiescent phases, so that the survival of...
Topics: NASA Technical Reports Server (NTRS), SATELLITE ATMOSPHERES, GAS GIANT PLANETS, GAS DENSITY,...
Current knowledge about dynamics and the thermal structure of the outer planets is reviewed with the aim of identifying important measurements which should be made in the post-Voyager era. The existence of jets and cloud bands is the puzzle that underlies all others. The discussion focuses on the particular case of Jupiter because the documentation is the most complete. It is argued that the gross dynamical parameters of the outer planetary atmospheres are the keys to their behaviors, rather...
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, PLANETARY ATMOSPHERES, STRATIFICATION,...
There are about 30 very large impact basins on Mars, > 1000 km in diameter, most of which are revealed by their topographic and/or crustal thickness signatures. Crater retention ages and model absolute ages suggest these all formed in a relatively short time (100-200 million years?), perhaps during a "Late Heavy Bombardment" (LHB) caused by the evolution of the orbits of the giant planets. This so-called "Nice Model" of planetary formation may explain the LHB on the Moon...
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, CRATERS, CRUSTS, STRUCTURAL BASINS,...
We feel that at the present moment the available theoretical models of the Kuiper belt are still in advance of the data, and thus our main task has been to conduct observational work guided by theoretical motivations. Our efforts over the past year can be divided into four categories: A) Wide-field Searches for Kuiper Belt Objects; B) Pencil-beam Searches for Kuiper Belt Objects; C) Wide-field Searches for Moons of the Outer Planets; D) Pencil-beam Searches for Faint Uranian and Neptunian...
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, NATURAL SATELLITES, KUIPER BELT,...
Models of planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may...
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, PLANETARY EVOLUTION, PLANETARY SYSTEMS,...
The aim of this project is to develop a comprehensive global picture of the physical conditions in, and evolutionary timescales of, pre-main sequence accretion disks. The results of this work will help constrain the initial conditions for planet formation. To this end we plan to: (1) Develop much larger samples of 3-10 Myr-old stars to provide better empirical constraints on protoplanetary disk evolution; (2) Study the dusty emission and accretion rates in these systems, with ages closer to the...
Topics: NASA Technical Reports Server (NTRS), ACCRETION DISKS, PLANETARY EVOLUTION, PROTOPLANETARY DISKS,...
The contents include the following: 1) Dynamical Evolution of the Earth-Moon Progenitors. 2) Dynamical Connections between Giant and Terrestrial Planets. 3) Dynamics of the Upsilon Andromedae Planetary System. 4) Dynamics of the Planets Orbiting GJ 876. and 5) Integrators for Planetary Accretion in Binaries.
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, PLANETS, STABILITY, TERRESTRIAL PLANETS,...
This theoretical/observational project constrains structure of outer planet atmospheres and interiors through observational data. The primary observation tool is through observations of occultations of stars by outer solar system objects, which yield information about atmospheric temperatures and dynamics, and planetary dimensions and oblateness. The theoretical work relates the data to interior structures in a variety of ways.
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, PLANETARY ATMOSPHERES, PLANETARY...
The March 1994 Semi-Annual report for Studies of Extra-Solar Oort Clouds and the Kuiper Disk is presented. We are conducting research designed to enhance our understanding of the evolution and detectability of comet clouds and disks. This area holds promise for also improving our understanding of outer solar system formation, the bombardment history of the planets, the transport of volatiles and organics from the outer solar system to the inner planets, and to the ultimate fate of comet clouds...
Topics: NASA Technical Reports Server (NTRS), ACCRETION DISKS, COMETS, OORT CLOUD, PLANETARY EVOLUTION,...
A major effort was directed toward 951 Gaspra in preparation for the Galileo encounter in October 1991. Most of the observational work involved photometry, for purposes of investigating the rotational state and phase function of the asteroid to help plan the encounter, and for purposes of navigating the spacecraft to the object. Work was also done with radiometric data obtained with the IRTF at NASA's request, for which simultaneous visible photometry was acquired with the University of Hawaii...
Topics: NASA Technical Reports Server (NTRS), ASTEROIDS, ASTROMETRY, INFRARED PHOTOMETRY, INFRARED SPECTRA,...
The aim of this project was to develop a comprehensive global picture of the physical conditions in, and evolutionary timescales of, pre-main sequence accretion disks. The results of this work will help constrain the initial conditions for planet formation. To this end we: (1) Developed detailed calculations of disk structure to study physical conditions and investigate the observational effects of grain growth in T Tauri disks; (2) Studied the dusty emission and accretion rates in older disk...
Topics: NASA Technical Reports Server (NTRS), ACCRETION DISKS, EVOLUTION (DEVELOPMENT), PLANETARY...
Missions to the outer planets for spacecraft with a solar-electric propulsion system (SEPS) and that utilize a single Venus gravity assist are investigated. The trajectories maximize the delivered mass to the target planet for a range of flight times. A comparison of the trajectory characteristics (delivered mass, launch energy and onboard propulsive energy) is made for various Venus gravity assist opportunities. Methods to estimate the delivered mass to the outer planets are developed.
Topics: NASA Technical Reports Server (NTRS), SOLAR ELECTRIC PROPULSION, GRAVITATIONAL EFFECTS, GAS GIANT...
This proposal is directed towards the observational exploration of the irregular satellite systems of the planets. Primarily we use large-format CCD cameras on the world's largest telescopes, on Mauna Kea, to discover new irregular satellites and then to monitor their positions in order to ascertain their orbital characteristics. Separate observations are taken to determine the physical properties of the irregular satellites. The big picture science objective is to determine how these...
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, ASTRONOMY, PLANETARY STRUCTURE, CCD...
Our ongoing research program combines extensive deep and wide-field observations using a variety of observational platforms with numerical studies of the dynamics of small bodies in the outer solar system in order to advance the main scientific goals of the community studying the Kuiper belt and the outer solar system. These include: (1) determining the relative populations of the known classes of KBOs as well as other possible classes; ( 2 ) determining the size distributions or luminosity...
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, SOLAR SYSTEM, KUIPER BELT, LUMINOSITY,...
The Moon is believed to have formed from debris produced by a giant impact of a Mars sized body with the Earth (at around 4.51 Ga), forming a primitive body with a thick global layer of melt referred to as the Lunar Magma Ocean (LMO). The crystallization of LMO created internal stratification of the Moon forming main geochemical reservoirs. The surface features on the Moon were shaped by the subsequent collision with several large impactors during a short period of time (3.9-4.0 Ga). This...
Topics: NASA Technical Reports Server (NTRS), MOON, GEOCHEMISTRY, CHRONOLOGY, ASTEROID BELTS, GAS GIANT...
We live in a planetary system with 2 gas giant planets, and as a resu lt of RV, transit, microlensing, and transit timing studies have ide ntified hundreds of giant planet candidates in the past 15 years. Su ch studies have preferentially concentrated on older, low activity So lar analogs, and thus tell us little about .when, where, and how gian t planets form in their disks, or how frequently they form in disks associated with intermediate-mass stars.
Topics: NASA Technical Reports Server (NTRS), GAS GIANT PLANETS, EXTRASOLAR PLANETS, PROTOPLANETARY DISKS,...
The Department of Energy is considering the current Stirling Technology Corporation 55 We Stirling Technology Demonstration Convertor as a baseline option for an advanced radioisotope power source for the Outer Planets/Solar Probe project of Jet Propulsion Laboratory and other missions. However, since the Technology Demonstration Convertor contains organic materials chosen without any special consideration of flight readiness, and without any consideration of the extremely high radiation...
Topics: NASA Technical Reports Server (NTRS), ORGANIC MATERIALS, IONIZING RADIATION, SOLAR PROBES, STIRLING...
Several documents in a collection discuss a proposal to use clusters of appropriately phased, relatively small microwave antennas to obta in high levels of effective isotropically radiated power (EIRP) for transmission of data from spacecraft to Earth during exploration of d istant planets.
Topics: NASA Technical Reports Server (NTRS), SPACECRAFT ANTENNAS, TRANSMISSION EFFICIENCY, ANTENNA DESIGN,...
The race to the Moon dominated manned space Fight during the 1960's. and culminated in Project Apollo. which placed 12 humans on the Moon Unbeknownst to the public at that time, several U.S. Government agencies sponsored a project that could have conceivably, placed 150 people on the Moon and eventually sent crewed expeditions to Mars and the outer Planets. These feats could have possibly been accomplished during, the same period of time as Apollo. and for approximately the same cost. The...
Topics: NASA Technical Reports Server (NTRS), NUCLEAR PROPULSION, MOON, EXPEDITIONS, SOLAR SYSTEM,...
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Sep 20, 2010
09/10
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NON
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This report details the rules and regulations for obtaining a British airworthiness certificate. Aircraft loading and construction are especially important.
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Topics: AIRGLOW, PARTICLE ENERGY, THERMOSPHERE, ULTRAVIOLET EMISSION, ULTRAVIOLET SPECTROMETERS,...
Atmospheric mass loss from Hot Jupiters can be large due to the close proximity of these planets to their host star and the strong radiation the planetary atmosphere receives. On Earth, a major contribution to the acceleration of atmospheric ions comes from the vertical separation of ions and electrons, and the generation of the ambipolar electric field. This process, known as the "polar wind," is responsible for the transport of ionospheric constituents to Earth's magnetosphere,...
Topics: NASA Technical Reports Server (NTRS), PLANETARY ATMOSPHERES, GAS GIANT PLANETS, EXTRASOLAR PLANETS,...
The James Webb Space Telescope (JWST) will be a nearly ideal machine for acquiring the transmission and emission spectra of transiting exoplanets over its large wavelength range 0.7 - 28 microns. The NIRSpec, NIRCam, nTFI, and MIRI instruments will have spectroscopic capabilities that span spectral resolutions from 20 - 3000 and can cover up to 2 - 3 octaves in wavelength simultaneously. This will allow observing multiple molecular features at once, facilitating the separation of atmospheric...
Topics: NASA Technical Reports Server (NTRS), ECLIPSES, EXTRASOLAR PLANETS, JAMES WEBB SPACE TELESCOPE,...
The composition of material condensed in the outer solar system is very dependent on the state of carbon and oxygen in the solar or circumplanetary nebula, since oxygen is the dominant solid-forming element in a solar composition gas (in the form of silicates and water ice), and carbon is about half as abundant. Past discussions of solid material formed in these regions have focused on differences expected between material formed near giant planets where carbon is generally expected to be in...
Topics: NASA Technical Reports Server (NTRS), SOLAR NEBULA, SATURN SATELLITES, CARBON, OXYGEN, SILICATES,...
Despite more than a decade of coronagraphic imaging of debris disk candidate stars, only 16 have been imaged in scattered light. Since imaged disks provide our best insight into processes which sculpt disks, and can provide signposts of the presence of giant planets at distances which would elude radial velocity and transit surveys, we need to understand under what conditions we detect the disks in scattered light, how these disks differ from the majority of debris disks, and how to increase...
Topics: NASA Technical Reports Server (NTRS), CORONAGRAPHS, HUBBLE SPACE TELESCOPE, IMAGING TECHNIQUES,...
The purpose of the project is to perform laboratory measurements of reaction rate coefficients at low temperature. The reactions and temperatures of interest are those that are important in the chemistry of the hydrocarbon rich atmospheres of the outer planets and their satellites. In this stage of the study we are investigating reactions of ethynyl radicals, C2H, with acetylene (C2H2), methane (CH4), and hydrogen (H2). In the previous status report from 24 Jan. 1992, we reported on the...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, COEFFICIENTS, GAS GIANT PLANETS, LOW...
We present L' band (3.8 Micron) MMT/Clio high-contrast imaging data for the nearby star GJ 758, which was recently reported by Thalmann et al. (2009) to have one - possibly two - faint comoving companions (GJ 7588 and "C", respectively). GJ 758B is detected in two distinct datasets. Additionally, we report a \textit{possible} detection of the object identified by Thalmann et al as "GJ 758C" in our more sensitive dataset, though it is likely a residual speckle. However, if it...
Topics: NASA Technical Reports Server (NTRS), BROWN DWARF STARS, EXTRASOLAR PLANETS, GAS GIANT PLANETS,...
