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All sourcesNASA NTRSDOE OSTI
NASA NTRS2008

Phoenix - the First Mars Scout Mission

As the first of the new Mars Scouts missions, the Phoenix project was selected by NASA in August of 2003. Four years later, almost to the day, Phoenix was launched from Cape Canaveral Air Station and successfully injected into an interplanetary trajectory on its way to Mars. This paper will highlight some of the key changes since the 2006 IEEE paper of the same name, as well as activities, challenges and problems encountered on the way to the launch pad. Phoenix Follows the water responding directly to the recently published data from Dr. William Boynton, PI (and Phoenix co-I) of the Mars Odyssey Gamma Ray Spectrometer (GRS). GRS data indicate extremely large quantities of water ice (up to 50% by mass) within the upper 50 cm of the northern polar regolith. Phoenix will land within the north polar region at 68.2 N, 233.4 W identified by GRS to harbor near surface water ice and provide in-situ confirmation of this extraordinary find. Our mission will investigate water in all its phases, and will investigate the history of water as evidenced in the soil characteristics that will be carefully examined by the powerful suite of onboard instrumentation. Access to the critical subsurface region expected to contain this information is made possible by a third generation robotic arm capable of excavating the expected Martian regolith to a depth of 1m. Phoenix has four primary science objectives: 1) Determine the polar climate and weather, interaction with the surface, and composition of the lower atmosphere around 70 N for at least 90 sols focusing on water, ice, dust, noble gases, and CO2. Determine the atmospheric characteristics during descent through the atmosphere. 2) Characterize the geomorphology and active processes shaping the northern plains and the physical properties of the near surface regolith focusing on the role of water. 3) Determine the aqueous mineralogy and chemistry as well as the adsorbed gases and organic content of the regolith. Verify the Odyssey discovery of near-surface ice. 4) Characterize the history of water, ice, and the polar 1 1-4244-1488-1/08/$25.00 2008 IEEE 2 IEEEAC paper#1579, Version 1, Updated 2008:01:09 climate. Determine the past and present biological potential of the surface and subsurface environments.

Mars exploration↗
NASA NTRS1991

Water resources and hydrology of Mars

The surface of Mars has been extensively modified by a large variety of water erosional and depositional processes. Although liquid water is presently unstable on the planet's surface, in its cold, hyperarid climate, there is abundant geomorphological evidence of past fluvial valley development multiple episodes of catastrophic flooding, periglacial landforms, ice-related permafrost, lake deposits, eroded impact craters and possible glacial landforms throughout much of Mars' geological history. The amount of water required to form such features is estimated to be equivalent to a planet-wide layer approximately 50 meters deep. Some of this water undoubtedly was removed from the planet by atmospheric escape processes, but much probably remains in the subsurface of Mars. Jakosky summarized the present partitioning of water on Mars, expressed as an average global depth, as follows: in the polar caps, 30 meters; in the megaregolith, 500 to 1000 meters; structurally bound in clays, 10 meters; and in high latitude regolith, a few meters. However, most of this water is probably in the form of ice, except in anomalous areas of possible near surface liquid water, and in regions where hydrothermal systems are still active. The best locations for prospecting are those areas where water or ice is sufficiently concentrated at shallow enough depths to make it feasible to pump out or mine.

Baker, V. R.↗
NASA NTRS1995

Winter Storm Zones on Mars

Preferred regions of weather activity in Mars' winter middle latitudes-so called 'storm zones' are found in a general circulation model of Mars' atmospheric circulation. During northern winter, these storm zones occur in middle latitudes in the major planitia (low-relief regions) of the western and eastern hemisphere. In contrast, the highlands of the eastern hemisphere are mostly quiescent. Compared to Earth's storm zones where diabatic heating associated with land-sea thermal contrasts is crucial, orography on Mars is fundamental to the regionalization of weather activity. Future spacecraft missions aimed at assessing Mars' climate and its variability need to include such regions in observation strategies.

Hollingsworth, J. L.↗
NASA NTRS1985

Comparative climatology - Mars and earth

Spacecraft missions to Mars during the 1960's and 1970's gave a remarkably detailed picture of the meteorological and climatological conditions that characterize its atmosphere. During the relatively brief history of close-up exploration of Mars, much of the ambiguity associated with the early telescopic observations has been resolved, and a new image of the red planet has emerged. Accurate measurements taken both from orbit and the surface reveal a cool, thin atmosphere that condenses, transports water, and generates clouds and dust storms, and that has a global-scale wind system not unlike the one known on earth. This paper highlights the current view of the Martian climate system and what controls it. For perspective, comparisons with earth's climate system are included where appropriate.

Haberle, R. M.↗
NASA NTRS1998

An Intercomparison of the Dynamical Cores of Global Atmospheric Circulation Models for Mars

This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. The focus of this JRI has been to evaluate the dynamical "cores" of two global atmospheric circulation models for Mars that are in operation at the NASA Ames Research Center. The two global circulation models in use are fundamentally different: one uses spherical harmonics in its horizontal representation of field variables; the other uses finite differences on a uniform longitude-latitude grid. Several simulations have been conducted to assess how the dynamical processors of each of these circulation models perform using identical "simple physics" parameterizations. A variety of climate statistics (e.g., time-mean flows and eddy fields) have been compared for realistic solstitial mean basic states. Results of this research have demonstrated that the two Mars circulation models with completely different spatial representations and discretizations produce rather similar circulation statistics for first-order meteorological fields, suggestive of a tendency for convergence of numerical solutions. Second and higher-order fields can, however, vary significantly between the two models.

Hollingsworth, Jeffery L.↗
NASA NTRS1998

An Intercomparison of the Dynamical Cores of Global Atmospheric Circulation Models for Mars

This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. The focus of this JRI has been to evaluate the dynamical 'cores' of two global atmospheric circulation models for Mars that are in operation at the NASA Ames Research Center. The two global circulation models in use are fundamentally different: one uses spherical harmonics in its horizontal representation of field variables; the other uses finite differences on a uniform longitude-latitude grid. Several simulations have been conducted to assess how the dynamical processors of each of these circulation models perform using identical 'simple physics' parameterizations. A variety of climate statistics (e.g., time-mean flows and eddy fields) have been compared for realistic solstitial mean basic states. Results of this research have demonstrated that the two Mars circulation models with completely different spatial representations and discretizations produce rather similar circulation statistics for first-order meteorological fields, suggestive of a tendency for convergence of numerical solutions. Second and higher-order fields can, however, vary significantly between the two models.

Hollingsworth, Jeffery L.↗
NASA NTRS1998

An Intercomparison of the Dynamical Cores of Global Atmospheric Circulation Models for Mars

This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Cen- ter and San Jose State University, Department of Meteorology. The focus of this JRI has been to evaluate the dynamical "cores" of two global atmospheric circulation models for Mars that are in operation at the NASA Ames Research Center. ne two global circulation models in use are fundamentally different: one uses spherical harmonics in its horizontal representation of field variables; the other uses finite differences on a uniform longitude-latitude grid. Several simulations have been conducted to assess how the dynamical processors of each of these circulation models perform using identical "simple physics" parameterizations. A variety of climate statistics (e.g., time-mean flows and eddy fields) have been compared for realistic solstitial mean basic states. Results of this research have demonstrated that the two Mars circulation models with completely different spatial representations and discretizations produce rather similar circulation statistics for first-order meteorological fields, suggestive of a tendency for convergence of numerical solutions. Second and higher-order fields can, however, vary significantly between the two models.

Hollingsworth, Jeffery L.↗
NASA NTRS2022

Assessing Bare-Ice Albedo Simulated By MAR Over the Greenland Ice Sheet (2000–2021) and Implications for Meltwater Production Estimates

Surface mass loss from the Greenland ice sheet (GrIS) has accelerated over the past decades, mainly due to enhanced surface melting and liquid water runoff in response to atmospheric warming. A large portion of runoff from the GrIS originates from exposure of the darker bare ice in the ablation zone when the overlying snow melts, where surface albedo plays a critical role in modulating the energy available for melting. In this regard, it is imperative to understand the processes governing albedo variability to accurately project future mass loss from the GrIS. Bare-ice albedo is spatially and temporally variable and contingent on non-linear feedbacks and the presence of light-absorbing constituents. An assessment of models aiming at simulating albedo variability and associated impacts on meltwater production is crucial for improving our understanding of the processes governing these feedbacks and, in turn, surface mass loss from Greenland. Here, we report the results of a comparison of the bare-ice extent and albedo simulated by the regional climate model Modèle Atmosphérique Régional (MAR) with satellite imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) for the GrIS below 70∘ N. Our findings suggest that MAR overestimates bare-ice albedo by 22.8 % on average in this area during the 2000–2021 period with respect to the estimates obtained from MODIS. Using an energy balance model to parameterize meltwater production, we find this bare-ice albedo bias can lead to an underestimation of total meltwater production from the bare-ice zone below 70∘ N of 42.8 % during the summers of 2000–2021.

albedo↗
NASA NTRS2001

Dry Mars: Parched Rocks and Fallen Dust

While "following the water" to find life on Mars, it is easy to overlook evidence that Mars is harshly dry, and to neglect ideas that do not invoke water. Direct evidence for a dry Mars comes from the ALH 84001 meteorite, which has seen little or no liquid water during its last 3.9 billion years on Mars. Its aridity is difficult to reconcile with a Mars of abundant near-surface surface water or with episodes of warm wet climate. Alternative scenarios are also possible, even likely, for the martian gullies and debris flows that have been cited as evidence of liquid water. It is reasonable that the gullies flows are the remnants of massive dust avalanches, comparable to large climax snow avalanches seen on Earth. Mars' surface is now desiccated, and at least part of it has been equally desiccated for the past 3.9 billion years. With this background, and the wealth of atmospheric, imaging, and chemical data available from Mars, one must be very cautious in evaluating claims for liquid water recently at or near Mars' surface. Additional information is contained in the original extended abstract.

Treiman, Allan H.↗
NASA NTRS1988

Zeolites on Mars: Possible environmental indicators in soils and sediments

Weathering products should serve as indicators of weathering environments and may provide the best evidence of the nature of climate change on Mars. No direct mineralogical measurements of Martian regolith were performed by the Viking missions, but the biology and X-ray fluorescence experiments provided some information on the physiochemical properties of Martian regolith. Most post-Viking studies of candidate weathering products have emphasized phyllosilicates and Fe-oxides; zeolites are potentially important, but overlooked, candidate Martian minerals. Zeolites would be important on Mars for three different reasons. First, they are major sinks of atmospheric gases and, per unit mass, are stronger and more efficient sorbents than are phyllosilicates. Secondly, they can be virtually unique sorbents and shelters for organic compounds and possible catalysts for organic-based reactions. Finally, their exchangeable ions are good indicators of the chemical properties of solutions with which they have communicated. Accordingly, the search for information on past compositions of the Martian atmosphere and hydrosphere should find zeolites to be rich repositories.

Ming, D. W.↗
NASA NTRS2012

Miniature Tunable Laser Spectrometers for Quantifying Atmospheric Trace Gases, Water Resources, Earth Back-Contamination, and In Situ Resource Utilization

The Tunable Laser Spectrometers (TLS) technique has seen wide applicability in gas measurement and analysis for atmospheric analysis, industrial, commercial and health monitoring and space applications. In Earth science using balloons and aircraft over 2 decades, several groups (JPL, NASA Langley & Ames, NOAA, Harvard U., etc) have demonstrated the technique for ozone hole studies, lab kinetics measurements, cloud physics and transport, climate change in the ice record. The recent availability of high-power (mW) room temperature lasers (TDL, IC, QC) has enabled miniaturized, high-sensitivity spectrometers for industry and space (1) Mars, Titan, Venus, Saturn, Moon (2) Commercial isotope ratio spectrometers are replacing bulkier, complex isotope ratio mass spectrometers.

Tunable laser spectrometers (TLS)↗
NASA NTRS1996

Planetary atmosphere evolution: do other habitable planets exist and can we detect them?

The goal of this conference is to consider whether it is possible within the next few decades to detect Earth-like planets around other stars using telescopes or interferometers on the ground or in space. Implicit in the term "Earth-like" is the idea that such planets might be habitable by Earth-like organisms, or that they might actually be inhabited. Here, I shall address two questions from the standpoint of planetary atmosphere evolution. First, what are the chances that habitable planets exist around other stars? And, second, if inhabited planets exist, what would be the best way to detect them?.

NASA Discipline Exobiology↗
NASA NTRS1992

Overview for the reanalysis of Mariner 9 UV spectrometer data for ozone, cloud, and dust abundances, and their interaction over climate timescales

Mariner 9 UV spectrometer data were reinverted for the ozone abundance, cloud abundance, dust abundance, and polar-cap albedo. The original reduction of the spectra ignored the presence of atmospheric dust and clouds, even though their abundance is substantial and can mask appreciable amounts of ozone if not accounted for (Lindner, 1988). The Mariner 9 ozone data has been used as a benchmark in all theoretical models of atmospheric composition, escape, and photochemistry. A second objective is to examine the data for the interrelationship of the ozone cycle, dust cycle, and cloud cycle, on an annual, inter-annual, and climatic basis, testing predictions by Lindner (1988). This also has implications for many terrestrial ozone studies, such as the ozone hole, acid rain, and ozone-smog. A third objective is to evaluate the efficacy of the reflectance spectroscopy technique at retrieving the ozone abundance on Mars. This would be useful for planning ozone observations on future Mars missions or the terrestrial troposphere.

Lindner, Bernhard Lee↗
NASA NTRS1993

Early Mars: The inextricable link between internal and external influences on valley network formation

The conditions under which the valley networks on the ancient cratered terrain on Mars formed are still highly debated within the scientific community. While liquid water was almost certainly involved, the exact mechanism of formation is uncertain. The networks most resemble terrestrial sapping channels, although some systems exhibit a runoff-dominated morphology. The major question in the formation of these networks is what, if anything, do they imply about early Martian climate? There are typically two major theories advanced to explain the presence of these networks. The first is that higher internal regolith temperatures, associated with a much higher heat flow 3.8 b.y. ago, would cause ground water to be closer to the surface than at present. Just how close to the surface ground water would have to exist in order to form these valley networks has recently been questioned. The second major theory is that early Mars had a much thicker atmosphere than at present, and an enhanced atmospheric greenhouse may have increased surface temperatures to near the freezing point of water. While recent calculations indicate that CO2 alone could not have produced the needed warming, the presence of other greenhouse gases may have contributed to surface warming.

Postawko, S. E.↗
NASA NTRS1998

Mars Volatiles and Climate Surveyor (MVACS) Integrated Payload for the Mars Polar Lander Mission

The Mars Volatiles and Climate Surveyor (MVACS) integrated payload for the Mars Polar Lander will be launched in January 1999, with a scheduled landing on Mars' south-polar layered deposits in December 1999. Over the course of its 90-day nominal mission during the martian southern spring and summer seasons, it will make in situ measurements that will provide new insights into the behavior and distribution of martian volatiles, MVACS consists of four major instrument systems: a surface stereo imager (SSI), which will acquire multispectral stereo images of the surface and atmosphere; a 2-m robotic arm (RA), which will dig a O.5-m deep trench and acquire surface and subsurface samples that will be imaged by a focusable robotic arm camera (RAC), which will take close-up images of surface and subsurface samples at a spatial resolution of 21 micron; a meteorology package (MET), which will make the first measurements of surface pressure, temperature, and winds in Mars' southern hemisphere and employ a tunable diode laser (TDL) spectrometer to measure the water-vapor concentration and isotopic composition of CO2 in the martian atmosphere; and a thermal and evolved gas analyzer (TEGA), which will use differential scanning calorimetry and TDL-evolved gas analysis to determine the concentrations of ices, adsorbed volatiles, and volatile-bearing minerals in surface and subsurface soil samples. The unique in situ measurements made by MVACS at its high-latitude landing site will define a number of important aspects of the physical, isotopic, and chemical nature of the martian near-surface and subsurface environment that will be valuable in better understanding Mars meteorites and returned samples, as well as in the search for martian resources that could be utilized by humans.

Paige, D. A.↗
NASA NTRSDate not supplied

Martian B Storm Evolution: Modeling Dust Activity over the Receding South Polar CO 2 Ice Cap at Southern Hemisphere Summer Solstice

Observations of annually recurring, elevated (25 km) atmospheric warming and associated dust concentrations over the south polar cap near Southern Hemisphere (SH) summer solstice are the defining features of the regional dust storm known as the B storm [1]. Our observational analysis of MCS and TES temperature and dust retrievals include all Mars Years (MY) lacking a global dust storm (GDS) between MY 26 and MY 33 (Figure 1). The data indicate the B storm is initiated around perihelion (L s =252°) in the southern midlatitudes and reaches maximum height and intensity over the south pole near SH summer solstice at L s ~267°. At peak intensity, mid-level atmospheric temperatures are elevated by as much as 30 K and mid-level atmospheric dust mixing ratios are more than triple pre-B storm levels (1.5-2 ppm to 7-8 ppm). Cap edge lifting may contribute significantly to initial dust mobilization in the B storm since surface wind stress along the receding cap edge is likely strengthened by the combined effects of the sea breeze circulation and katabatic winds at this time of year [2, 3, 4]. We are investigating dust lifting and lofting near the south pole of Mars during SH summer using the NASA Ames Mars Global Climate Model (MGCM). The NASA Ames MGCM is a finite-volume numerical model with a cubed sphere grid ideal for modeling processes at high latitudes. Initial simulations at low resolution (4x4 degrees) capture some elevated dust and associated warming at the south pole around L s =265°, but the model fails to capture the intensity of the B storm. We will examine and present the model-predicted surface stress and vertical velocities near the receding seasonal CO 2 cap edge and at the south pole during solstice. Finally, we will present higher resolution simulations to better capture small-scale dynamics and features at the pole.

Courtney M. L. Batterson↗
NASA NTRS1986

Approximate methods for finding CO2 15-micron band transmission in planetary atmospheres

Physical band models that use simplifying assumptions about the structure of the CO2 15-micron band are described and compared with the accurate line-by-line model of Fels and Schwarzkopf (1981). The methods have application to the models of the atmospheres of Venus, earth, and Mars. The narrow-band methods include a general random model and techniques employing the Malkmus (1967) line-strength distribution, and the accuracy of these models at low pressure is found to be sensitive to the line-strength distribution and the line shape. When combined with a simple Voigt parameterization, the more efficient approximate methods represented by an exponential wideband model are found to be almost as accurate as the expensive narrow-band models. Empirical logarithmic wideband models used in climate-modeling studies are found to be very efficient, but of limited range of validity.

Crisp, David↗
DOE OSTI2024

Fe-rich X-ray amorphous material records past climate and persistence of water on Mars

X-ray amorphous material comprises 15-73 wt.% of sedimentary rocks and eolian sediments in Gale crater. This material is variably siliceous and iron rich but aluminum poor. The presence of volatiles is consistent with the existence of incipient weathering products. To better understand the implications of this material for past aqueous conditions on Mars, here we investigate X-ray amorphous material formation and longevity within terrestrial iron rich soils with varying ages and environmental conditions using bulk and selective dissolution methods, X-ray diffraction, and transmission electron microscopy. Results indicate that in situ aqueous alteration is required to concentrate iron into clay-size fraction material. Cooler climates promote the formation and persistence of X-ray amorphous material whereas warmer climates promote the formation of crystalline secondary phases. Iron rich X-ray amorphous material formation and persistence on Mars are therefore consistent with past cool and relatively wet environments followed by long-term cold and dry conditions.

54 ENVIRONMENTAL SCIENCES↗