A5056310193- Planetary Science and Exploration
- Astro and Planetary Science
- Aeolian processes and effects
- Geology and Paleoclimatology Research
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Marine and environmental studies
- Biocrusts and Microbial Ecology
- Landslides and related hazards
- Maritime and Coastal Archaeology
- Methane Hydrates and Related Phenomena
- Image Processing and 3D Reconstruction
- Scientific Research and Discoveries
- Gamma-ray bursts and supernovae
- Remote Sensing and LiDAR Applications
- Geological formations and processes
- Paleontology and Stratigraphy of Fossils
- Hydrology and Sediment Transport Processes
- Atmospheric and Environmental Gas Dynamics
- 3D Surveying and Cultural Heritage
- Hydrocarbon exploration and reservoir analysis
- Ancient Mediterranean Archaeology and History
- Spaceflight effects on biology
- Spacecraft Design and Technology
- Space exploration and regulation
Planetary Science Institute
2014-2024
Population Services International
2021
University of Arizona
2013-2020
Lunar and Planetary Institute
2019
University of Tennessee at Knoxville
2008-2014
Laboratory for Atmospheric and Space Physics
2006-2008
University of Colorado Boulder
2006-2008
[1] Columbus crater in the Terra Sirenum region of Martian southern highlands contains light-toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate detail morphology, thermophysical properties, mineralogy, stratigraphy these deposits; explore their regional context; interpret crater's aqueous history. Hydrated mineral-bearing occupy discrete ring around walls are also exposed beneath younger materials, possibly lava flows,...
[1] Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of atmosphere, soils, and rocks. This paper provides an overview key discoveries between sols 511 2300, complementing earlier papers covering results from initial phases mission. Key new include (1) atmospheric argon measurements that demonstrate importance transport to winter carbon dioxide polar ice caps; (2) showing aeolian ripples were generated by easterly winds during...
A subset of the sinuous ridges (SRs) in Aeolis/Zephyria Plana (AZP) region Mars has been previously hypothesized to be inverted fluvial features, although precise induration and erosion mechanisms were not specified. Morphological observations thermal inertia data presented here support this hypothesis. variety can cause inversion, identification specific events that lead SR formation provide insights into sedimentological, geochemical, climatic processes region. Reconnaissance two...
Abstract Carbonates are key minerals for understanding ancient Martian environments because they indicators of potentially habitable, neutral‐to‐alkaline water and may be an important reservoir paleoatmospheric CO 2 . Previous remote sensing studies have identified mostly Mg‐rich carbonates, both in dust a Late Noachian rock unit circumferential to the Isidis basin. Here we report evidence older Fe‐ and/or Ca‐rich carbonates exposed from subsurface by impact craters troughs. These found...
[1] Although aeolian landforms are pervasive on Mars, evidence for contemporary activity has been limited. The next major campaign the Mars Exploration Rover “Opportunity” is investigation of ∼20 km diameter Endeavor crater, ∼6 to southeast rover's position as December 2010. We present from orbital imagery that eight bed forms (∼14,000 m2) in crater have active within past decade (2001–2009), at a spatial scale should be directly observable by Opportunity rim. Two dunes appear show...
Abstract One of the major Mars discoveries recent years is existence recurring slope lineae (RSL), which suggests that liquid water occurs on or near surface today. These dark and narrow features emerge from steep, rocky exposures incrementally grow, fade, reform a seasonal basis are detected in images High Resolution Imaging Science Experiment camera. RSL known to occur at scattered midlatitude equatorial sites with little spatial connection one another. exception low‐albedo slopes Melas...
Abstract Repeat, high-resolution imaging of dunes within the Martian north polar erg have shown that these dune slopes are very active, with alcoves forming along brink each Mars year. In some areas, a few hundred cubic metres downslope sand movement been observed, sometimes moving ‘backwards’. Based on morphological and activity-timing similarities features to southern gullies, identifying processes is likely relevance for understanding general evolution/modification gullies. To determine...
Wind has been an enduring geologic agent throughout the history of Mars, but it is often unclear where and why sediment mobile in current epoch. We investigated whether eolian bed-form (dune ripple) transport rates are depressed or enhanced some areas by local regional boundary conditions (e.g., topography, sand supply/availability). Bed-form heights, migration rates, fluxes all span two to three orders magnitude across we found that with highest concentrated regions: Syrtis Major,...
Aeolian megaripples, with 5- to 50-m spacing, are abundant on the surface of Mars. These features were repeatedly targeted by high-resolution orbital images, but they have never been observed move. Thus, aeolian megaripples (especially bright-toned ones often referred as Transverse Ridges-TARs) interpreted relict a past climate. In this report, we show evidence for migration spaced 1 35 m (5 average) in two equatorial areas Mars indicating that and small TARs can be active today. The moving...
Abstract Aeolian processes have likely been the predominant geomorphic agent for most of Mars' history and potential to produce relatively young exposure ages geologic units. Thus, identifying local evidence aeolian erosion is highly relevant selection landing sites future missions, such as Mars 2020 Rover mission that aims explore astrobiologically ancient environments. Here we investigate wind‐driven activity at eight candidate‐landing constrain these locations. To demonstrate our methods,...
Many discoveries of active surface processes on Mars have been made due to the availability repeat high-resolution images from High Resolution Imaging Science Experiment (HiRISE) onboard Reconnaissance Orbiter. HiRISE stereo are used make digital terrain models (DTMs) and orthorectified (orthoimages). DTMs orthoimage time series crucial for advancing study such as recurring slope lineae, dune migration, gully activity, polar processes. We describe process making DTMs, series, DTM mosaics,...
Abstract Change detection analyses of aeolian bedforms (dunes and ripples), using multitemporal images acquired by the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE), can reveal migration on Mars. Here we investigated bedform mobility (evidence wind‐driven or activity), from analysis HiRISE temporal image pairs, dune field modification (i.e., apparent presence/lack changes degradation due to nonaeolian processes) through use a stability index SI (1–6; higher...
Abstract Recurring slope lineae (RSL) are dark linear markings on Mars that regrow annually and likely originate from the flow of either liquid water or granular material. Following great dust storm (or planet‐encircling event, PEDE) year (MY) 34, Reconnaissance Orbiter/High Resolution Imaging Science Experiment has seen many more candidate RSL than in typical years. They have been imaged at 285 unique locations August 2018 (when atmosphere was clearing as PEDE decayed) to 2019, about half...
The Mars Reconnaissance Orbiter has been orbiting since 2006 and acquired >80,000 HiRISE images with sub-meter resolution, contributing to over 2000 peer-reviewed publications, provided the data needed enable safe surface landings in key locations by several rovers or landers. This paper describes changes science planning, processing, analysis tools initial Primary Science Phase 2006–2008. These affect used requested community how they should interpret data. There have a variety of...
Abstract Mars has an extensive yet poorly understood cryosphere. Nevertheless, both direct and indirect evidence indicates buried ice across the midlatitudes, including locations where it is presently unstable. While much progress been made in exploring processes responsible for deposition preservation during recent climatic fluctuations, a global assessment of multiple reservoirs remains elusive. Motivated by science need to find suitable human landing sites, Subsurface Water Ice Mapping...
Greater than 15,000 km 2 of the layered deposits within Valles Marineris are associated with water‐altered minerals, yet their origin and history alteration remain a mystery. There numerous competing hypotheses for formation interior including aeolian, lacustrine, volcanic. Recent orbiter spectroscopic data have indicated that water has played role in geological history. Thermal Emission Spectrometer (TES) measurements revealed significant crystalline hematite‐bearing Marineris, typically...