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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Pickup Ion Mass Spectrometry for Surface Bounded Exospheres and Composition Mapping of Lunar and Planetary Surfaces

Many of the small to medium sized objects in the solar system can be characterized as having surface bounded exospheres, or atmospheres so tenuous that scale lengths for inter-particle collisions are much larger than the dimensions of the objects. The atmospheres of these objects are the product of their surfaces, both the surface composition and the interactions that occur on them and also their interiors when gases escape from there. Thus by studying surface bounded exospheres it is possible to develop insight into the composition and processes that are taking place on the surface and interiors of these objects. The Moon and Mercury are two examples of planetary bodies with surface bounded exospheres that have been studied through spectroscopic observations of sodium, potassium, and, on the moon, mass spectrometric measurements of lunar gases such as argon and helium.

Keller, J. W.↗
NASA NTRS1973

The annual radiation balance of the earth-atmosphere system during 1969-70 from Nimbus 3 measurements.

Measurements of reflected solar radiation and emitted thermal radiation taken with a radiometer on the meteorological satellite Nimbus 3 during 10 semi-monthly periods (April-15 August, 3-17 October, 1969; 21 January-3 February, 1970) provided for the first time high-resolution data on the earth's annual global radiation budget. Results on the planetary albedo, the amount of absorbed solar radiation, the infrared radiation loss to space, and the radiation balance of the earth-atmosphere system are discussed at various scales: global, hemispherical, and zonal averages; as well as global and polar maps with a spatial resolution of about synoptic scale.

Raschke, E.↗
DOE OSTI2025

Multiscale astrobiology with the Vera C. Rubin Observatory Legacy Survey of Space and Time

The Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) presents an unprecedented opportunity to advance the search for astrobiologically relevant data across diverse astronomical environments. Through its extensive imaging capabilities, LSST will enhance our inventory of Solar System objects and assess their potential astrobiological conditions. Beyond the Solar System, LSST will survey billions of stars, contributing to the detection of exoplanets, characterizing planetary atmospheres at a zeroth-order level, identifying transient phenomena, and exploring conditions within habitable zones. In this paper, we highlight LSST’s unique contribution to astrobiology, complementing other missions and expanding the search for life beyond Earth in the coming decades.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1986

Climatic consequences of very high CO2 levels in Earth's early atmosphere

Earth has approximately 60 bars of carbon dioxide tied up in carbonate rocks, or roughly 2/3 the amount of CO2 of the atmosphere of Venus. Two different lines of evidence, one based on thermodynamics and the other on geochemical cycles, indicate that a substantial fraction of thes CO2 may have resided in the atmosphere during the first few hundred million years of the Earth's history. A natural question which arises is whether this much CO2 would have resulted in a runaway greenhouse effect. One dimensional radiative/convective model calculations presented showed that the surface temperature of a hypothetical primitive atmosphere containing 20 bars of CO2 was less than 100 C; thus no runaway greenhouse effect would have occurred. The climatic stability of the early atmosphere is a consequence of three factors: reduced solar luminosity at that time, an increase in planetary albedo caused by Rayleigh scattering by CO2, and the stabilizing effects of a moist convection. The latter two factors are sufficient to prevent a CO2 induced runaway greenhouse effect on the present Earth as well, for CO2 levels up to 100 bars. Further studies are being undertaken to determine whether a runaway greenhouse effect could have occurred during the latter stages of the accretion process and, if so, whether it would have collapsed one the influx of material slowed down.

Katsing, J. F.↗
NASA NTRS1988

Origin of the solar system

The current status of the classical model of solar-system formation is surveyed, reviewing the results of recent observational and theoretical investigations. Topics addressed include interstellar clouds, the collapse of interstellar gas, the primitive solar nebula, the formation of the sun, planetesimal accumulation, planetary accumulation, major planetary collisions, the development of planetary atmospheres, and comets. The relative merits of conflicting theories on many key problems are indicated, with reference to more detailed reviews in the literature.

Cameron, A. G. W.↗
NASA NTRS1988

Topical Conference on the Origin of the Earth

The abstracts are presented on the topic of the origin of the Earth. The subject of planetary evolution from inner solar system plantesimals through the formation and composition of the Earth's atmosphere and the physical structure of the Earth and the Moon is explored in great variety.

Source record↗
NASA NTRS1991

U.S. National Report to International Union of Geodesy and Geophysics 1987-1990; Proceedings of the IUGG General Assembly, 20th, Vienna, Austria, Aug. 11-24, 1991

An authoritative record of contributions of geophysical research in the U.S. during 1987-1990 is reported. Major areas of research include atmospheric sciences, geodesy, hydrology, planetology, geomagnetism, paleomagnetism, volcanology, geochemistry, petrology, oceanography, seismology, tectonophysics, and solar-planetary relations.

Shea, Margaret A.↗
NASA NTRS2008

Messenger Observations of Mercury's Bow Shock and Magnetopause

The MESSENGER spacecraft made the first of three flybys of Mercury on January 14.2008 (1). New observations of solar wind interaction with Mercury were made with MESSENGER'S Magnetometer (MAG) (2.3) and Energetic Particle and Plasma Spectrometer (EPPS) - composed of the Energetic Particle Spectrometer (EPS) and Fast Imaging Plasma Spectrometer (FIPS) (3,4). These MESSENGER observations show that Mercury's magnetosphere has a large-scale structure that is distinctly Earth-like, but it is immersed in a comet-like cloud of planetary ions [5]. Fig. 1 provides a schematic view of the coupled solar wind - magnetosphere - neutral atmosphere - solid planet system at Mercury.

Slavin J. A.↗
NASA NTRS1993

Evolution of the Martian atmosphere

Evolution of Mars' noble gases through two stages of hydrodynamic escape early in planetary history has been proposed previously by the author. In the first evolutionary stage of this earlier model, beginning at a solar age of approximately 50 m.y., fractionating escape of a H2-rich primordial atmosphere containing CO2, N2, and the noble gases in roughly the proportions found in primitive carbonaceous (CI) chondrites is driven by intense extreme-ultraviolet (EUV) leads to a long (approximately 80 m.y.) period of quiescence, followed by an abrupt degassing of remnant H2, CO2, and N2 from the mantle and of solar-composition noble gases lighter than Xe from the planet's volatile-rich accretional core. Degassed H refuels hydrodynamic loss in a waning but still potent solar EUV flux. Atmospheric Xe, Kr, and Ar remaining at the end of this second escape stage, approximately 4.2 G.y. ago, have evolved to their present-day abundances and compositions. Residual Ne continues to be modified by accretion of solar wind gases throughout the later history of the planet. This model does not address a number of processes that now appear germane to Martian atmospheric history. One, gas loss and fractionation by sputtering, has recently been shown to be relevant. Another, atmospheric erosion, appears increasingly important. In the absence then of a plausible mechanism, the model did not consider the possibility of isotopic evolution of noble gases heavier than Ne after the termination of hydrodynamic escape. Subsequent non-thermal loss of N was assumed, in an unspecified way, to account for the elevation of N from the model value of approximately 250 percent at the end of the second escape stage to approximately 620 percent today. Only qualitative attention was paid to the eroding effects of impact on abundances of all atmophilic species prior to the end of heavy bombardment approximately 3.8 G.y. ago. No attempt was made to include precipitation and recycling of carbonates in tracking the pressure and isotopic history of CO2.

Pepin, R. O.↗
NASA NTRS1986

multiplex gas chromatography: A novel analytical technique for future planetary studies

Determination of molecular species comprised of the biogenic elements in the atmospheres of planets and moons of the solar system is one the foremost requirements of the exobiologist studying chemical evolution and the origin of life. Multiplex chromatography is a technique where many samples are pseudo-randomly introduced to the chromatograph without regard to elution of preceding components. The resulting data are then reduced using mathematical techniques such as cross correlation or Fourier Transforms. To demonstrate the utility of this technique for future solar system exploration, chemical modulators were developed. Several advantages were realized from this technique in combination with these modulators: improvement in detection limits of several orders of magnitude, improvement in the analysis of complex mixtures by selectively modulating some of the components present in the sample, increase in the number of analyses that can be conducted in a given period of time, and reduction in the amount of expendables needed to run an analysis. In order to apply this technique in a real application, methane in ambient air was monitored continuously over a period of one week. By using ambient air as its own carrier all expendables beyond power were eliminated.

Valentin, J. R.↗
NASA NTRS1992

Modeling the Jovian aurora

The Jovian aurora is the most powerful aurora in the solar system, over 100 times more powerful than the Earth's aurora. These magnificent visual displays can provide important information about the planetary magnetosphere which is responsible for the acceleration of energetic particles that produce aurora at any planet. Similarities and differences in planetary auroral emissions are thus a viable means of classifying and studying both comparative atmospheric and magnetospheric processes. For instance, at Earth the solar wind is the primary source of auroral power while at Jupiter it is conjectured that the rotation of the planet is the major source of magnetospheric and auroral power. The purpose of this IR project was to develop a model: (1) for use in interpreting the existing set of multispectral observations of Jupiter's aurora; and (2) to design new experiments based on the findings to improve understanding of the underlying auroral processes.

Waite, J. Hunter, Jr.↗
NASA NTRS2003

Fullerenes and the Nature of Planetary Gases

Over the past several decades, two issues have dominated the discussion of planetary noble gas patterns: 1) the general resemblance of the noble gas abundances in carbonaceous chondrites to those measured in the Earth s atmosphere and; 2) atmospheric inventories of argon and neon that fall off significantly with increasing distance from the Sun. The recognition of the latter has led to the conclusion that the planetary component is not found on planets. In particular, the inability to explain the missing xenon reservoir, once thought to be sequestered in crustal rocks has been extremely troublesome. Some models have focused on various fractionations of solar wind rather than condensation as the process for the evolution of noble gases in the terrestrial planets. However, these models cannot explain the observed gradient of the gases, nor do they account for the similar Ne/Ar ratios and the dissimilar planetary Ar/Kr ratios. More recent studies have focused on hydrodynamic escape to explain the fractionation of gases, like neon, in the atmosphere and the mantle. Escape theory also seems to explain, in part, the isotopically heavy argon on Mars, however, it does not explain the discrepancies observed for the abundances of argon and neon on Venus and the Earth. This has led to the assumption that some combination of solar wind implantation, absorption and escape are needed to explain the nature of planetary noble gases.

Becker, Luann↗
NASA NTRS1980

Structure and meteorology of the middle atmosphere of Venus Infrared remote sensing from the Pioneer orbiter

The results of the Pioneer Venus orbiter radiometric temperature-sounding experiment are presented with examples of each of the primary data products. The measured temperature field is used to model the dynamics of the middle atmosphere from 60 to 140 km, and the thermal and solar fluxes are used to calculate the planetary radiation budget. The data for the diurnal variation of temperature at a given height show fairly small amplitudes up to an altitude of about 95 km, above which the day to night contrast increases rapidly with height. At the equator the dependence of temperature in the stratosphere on solar longitude is dominated by a wave number 2 solar tide with an amplitude of about 10 K. The equator to pole gradients are larger than expected, and the stratosphere is typically 15 to 20 K warmer at the pole than at the equator. The most significant discovery concerning the cloud morphology is a dipole structure consisting of two clearings in the cloud at locations straddling the pole and rotating around it every 2.7 days.

Taylor, F. W.↗
NASA NTRS1993

The Deep Space Network as an instrument for radio science research

Radio science experiments use radio links between spacecraft and sensor instrumentation that is implemented in the Deep Space Network. The deep space communication complexes along with the telecommunications subsystem on board the spacecraft constitute the major elements of the radio science instrumentation. Investigators examine small changes in the phase and/or amplitude of the radio signal propagating from a spacecraft to study the atmospheric and ionospheric structure of planets and satellites, planetary gravitational fields, shapes, masses, planetary rings, ephemerides of planets, solar corona, magnetic fields, cometary comae, and such aspects of the theory of general relativity as gravitational waves and gravitational redshift.

Asmar, S. W.↗
NASA NTRSDate not supplied

Enhancing the Uranus PlanetGRAM with 2D Zonally-Averaged Atmospheric Variabilities

We developed an open-source Python package (tweModel.py1) that generates the 2D zonally-averaged atmospheric structure of Jupiter, Saturn, Uranus, and Neptune to be used as reference bases for NASA’s Planetary Global Reference Atmospheric Model (PlanetGRAM) Suite. The package outputs temperatures, pressures, densities, and zonal winds as functions of altitude and latitude given an input cloud-top zonal wind profile and a zonally averaged temperature map using a discretized form of the geostrophic thermal wind equation (TWE). We present 2D atmospheric structure outputs for Uranus in detail. Our results will be incorporated in the PlanetGRAM Suite to aid in the development of future in-situ missions in the outer solar system including the recently prioritized Uranus Flagship mission.

Uranus↗
NASA NTRS2001

Laboratory for Extraterrestrial Physics

The NASA Goddard Space Flight Center (GSFC) Laboratory for Extraterrestrial Physics (LEP) performs experimental and theoretical research on the heliosphere, the interstellar medium, and the magnetospheres and upper atmospheres of the planets, including Earth. LEP space scientists investigate the structure and dynamics of the magnetospheres of the planets including Earth. Their research programs encompass the magnetic fields intrinsic to many planetary bodies as well as their charged-particle environments and plasma-wave emissions. The LEP also conducts research into the nature of planetary ionospheres and their coupling to both the upper atmospheres and their magnetospheres. Finally, the LEP carries out a broad-based research program in heliospheric physics covering the origins of the solar wind, its propagation outward through the solar system all the way to its termination where it encounters the local interstellar medium. Special emphasis is placed on the study of solar coronal mass ejections (CME's), shock waves, and the structure and properties of the fast and slow solar wind. LEP planetary scientists study the chemistry and physics of planetary stratospheres and tropospheres and of solar system bodies including meteorites, asteroids, comets, and planets. The LEP conducts a focused program in astronomy, particularly in the infrared and in short as well as very long radio wavelengths. We also perform an extensive program of laboratory research, including spectroscopy and physical chemistry related to astronomical objects. The Laboratory proposes, develops, fabricates, and integrates experiments on Earth-orbiting, planetary, and heliospheric spacecraft to measure the characteristics of planetary atmospheres and magnetic fields, and electromagnetic fields and plasmas in space. We design and develop spectrometric instrumentation for continuum and spectral line observations in the x-ray, gamma-ray, infrared, and radio regimes; these are flown on spacecraft to study the interplanetary medium, asteroids, comets, and planets. Suborbital sounding rockets and groundbased observing platforms form an integral part of these research activities. This report covers the period from approximately October 1999 through September 2000.

Vondrak, Richard R.↗
NASA NTRS1965

Research reports, July 1, 1964 - June 30, 1965

Compilation of research reports in astronomy, geophysics, nucleosynthesis, stellar structure and evolution, solar system origin, and atmospheric dynamics and turbulence

STELLAR EVOLUTION↗
NASA NTRS2002

The Solar Connections Observatory for Planetary Environments

The NASA Sun-Earth Connection theme roadmap calls for comparative study of how the planets, comets, and local interstellar medium (LISM) interact with the Sun and respond to solar variability. Through such a study we advance our understanding of basic physical plasma and gas dynamic processes, thus increasing our predictive capabilities for the terrestrial, planetary, and interplanetary environments where future remote and human exploration will occur. Because the other planets have lacked study initiatives comparable to the terrestrial ITM, LWS, and EOS programs, our understanding of the upper atmospheres and near space environments on these worlds is far less detailed than our knowledge of the Earth. To close this gap we propose a mission to study {\it all) of the solar interacting bodies in our planetary system out to the heliopause with a single remote sensing space observatory, the Solar Connections Observatory for Planetary Environments (SCOPE). SCOPE consists of a binocular EUV/FUV telescope operating from a remote, driftaway orbit that provides sub-arcsecond imaging and broadband medium resolution spectro-imaging over the 55-290 nm bandpass, and high (R>10$^{5}$ resolution H Ly-$\alpha$ emission line profile measurements of small scale planetary and wide field diffuse solar system structures. A key to the SCOPE approach is to include Earth as a primary science target. From its remote vantage point SCOPE will be able to observe auroral emission to and beyond the rotational pole. The other planets and comets will be monitored in long duration campaigns centered when possible on solar opposition when interleaved terrestrial-planet observations can be used to directly compare the response of both worlds to the same solar wind stream and UV radiation field. Using a combination of observations and MHD models, SCOPE will isolate the different controlling parameters in each planet system and gain insight into the underlying physical processes that define the solar connection.

Oliversen, Ronald J.↗