A5063384570- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Space exploration and regulation
- Geology and Paleoclimatology Research
- Space Satellite Systems and Control
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Spaceflight effects on biology
- Isotope Analysis in Ecology
- Methane Hydrates and Related Phenomena
- Spacecraft and Cryogenic Technologies
- Chemical Analysis and Environmental Impact
- Geological and Geochemical Analysis
- Geomagnetism and Paleomagnetism Studies
- Health and Medical Research Impacts
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- Climate Change and Geoengineering
- Spacecraft Design and Technology
- Astrophysics and Star Formation Studies
- Career Development and Diversity
Johns Hopkins University Applied Physics Laboratory
2021-2025
Lunar and Planetary Institute
2018-2023
Universities Space Research Association
2015-2023
Jet Propulsion Laboratory
2021
Purdue University West Lafayette
2021
Johnson Space Center
2021
Western University
2021
Arecibo Observatory
2014-2017
University of Arizona
2016
University of Puerto Rico at Arecibo
2016
Recurring Slope Lineae (RSL) are small scale seasonal flow features identified by Mars Reconnaissance Orbiter that present several interesting characteristics such as an albedo contrast, dependence, and a strong preference for equator‐facing slopes. All of these strongly suggest thermally driven mechanism liquid triggered or dominated flow. Here we investigate the possibility formed melting brines various compositions via combination thermodynamic kinetic numerical models. Results solution...
Abstract The Miniature Radio Frequency instrument (Mini-RF) on the Lunar Reconnaissance Orbiter obtained widespread synthetic aperture radar observations of Moon in S band (12.6 cm), including nearly complete coverage at both lunar poles. currently archived monostatic data have spatial offsets from reference frame, making them more difficult to compare other sets. To address this issue, we developed a new algorithm for spatially controlling Mini-RF S-band set and orthorectifying these onto...
Abstract We report statistically significant detections of nonradial, nongravitational accelerations based on astrometric data in the photometrically inactive objects 1998 KY 26 , 2005 VL 1 2016 NJ 33 2010 65 RH 120 and RF 12 . The magnitudes are greater than those typically induced by Yarkovsky effect, there is no radiation-based, nonradial effect that can be so large. Therefore, we hypothesize driven outgassing calculate implied H 2 O production rates for each object. attempt to reconcile...
Abstract The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) spacecraft mission characterized collected a sample from asteroid (101955) Bennu. After the OSIRIS-REx Sample Return Capsule released to Earth’s surface in 2023 September, diverted into new orbit that encounters (99942) Apophis 2029, enabling second with same unique capabilities: OSIRIS–Apophis (APEX). On 2029 April 13, 340 m diameter will draw within ∼32,000 km of surface,...
Abstract We successfully observed 191 near-Earth asteroids using the Arecibo Observatory’s S-band planetary radar system from 2017 December through 2019 December. present cross sections for 167 asteroids; circular-polarization ratios 112 based on Doppler-echo-power spectra measurements; and albedos, constraints size spin periods, surface-feature shape evaluation 37 selected delay-Doppler images with a range resolution of 75 m or finer. Out 33 an estimated effective diameter at least 200...
Abstract One of the youngest features on Moon is Tycho, an 85 km diameter impact crater with a vast ray system that spans much lunar nearside. As such, it serves as important stratigraphic marker for Moon. Tycho’s longest rays crosses South Pole, where intersects several candidate landing sites NASA’s Artemis III mission, which intends to return new samples. Identification ray-related effects are thus understand provenance collected material. To help contextualize sampling strategies, here...
NASA’s Mini-RF instrument on the Lunar Reconnaissance Orbiter (LRO) is a hybrid-polarized, dual-frequency synthetic aperture radar (SAR) that operates at S- (12.6 cm) and X/C-band (4.2 . initially operated as monostatic system – i.e., antenna transmitter receiver co-located. A anomaly led to transitioning bistatic architecture transmitting from Arecibo Observatory (AO) or Goldstone deep space communications complex DSS-13 receiving LRO spacecraft. These data can be used...
Iapetus, the outermost regular satellite of Saturn, has a drastic albedo dichotomy and an equatorial circumferential ridge that reaches heights 20 km widths 70 km. This moon is thought to have formed concurrently with so would experienced intense bombardment after its formation. The ridge, which been inferred be one most ancient features on Iapetus' surface, could reasonably expected eroded by impacts; however, it retained long continuous sections nearly pristine triangular shape slopes...
The Mars Science Laboratory (MSL) Rover Environmental Monitoring Station (REMS) has now made continuous in situ meteorological measurements for several Martian years at Gale crater, Mars. Of importance the search liquid formation are REMS' of ground temperature and in-air relative humidity, which is with respect to ice. Such data can constrain surface subsurface stability brines. Here we use updated calibrations REMS consistent humidity comparisons (i.e., versus ice) investigate potential...
There exists a positive correlation between orbital eccentricity and the average stellar flux that planets receive from their parent star. Often, though, it is assumed equilibrium temperature would correspondingly increase with eccentricity. Here we test this assumption by calculating comparing analytic solutions for both spatial temporal averages of distance, flux, temperature. Our show planet, constant albedo, slowly decreases until converging to value 90% circular orbit. This might be...
We combine experimentally verified constraints on brine thermodynamics along with a global circulation model to develop new extensive framework of stability the surface and subsurface Mars. Our work considers all major phase changes (i.e., evaporation, freezing, boiling) is consistent, regardless composition, so it applicable any relevant find that equatorial regions typically have temperatures too high for stable brines, while latitudes are susceptible permanent freezing. In subsurface,...
Abstract Ground-based planetary radar observations first revealed deposits of potentially nearly pure water ice in some permanently shadowed regions (PSRs) on Mercury’s poles. Later, the MESSENGER spacecraft confirmed icy nature deposits, as well their location within PSRs. Considering geologic context provided by MESSENGER, we further characterized north polar pairing data with new Arecibo S -band observations. Here show that PSRs have a gradational pattern properties is likely associated...
Eurotium halophilicum is psychrotolerant, halophilic, and one of the most-extreme xerophiles in Earth’s biosphere. We already know that this ascomycete grows close to 0 °C, at high NaCl, and—under some conditions—down 0.651 water-activity. However, there a paucity information about how it achieves extreme stress tolerance given dynamic water regimes surface habitats on which commonly occurs. Here, against backdrop global climate change, we investigated biophysical interactions E. with its...
Abstract The Lunar CRater Observations and Sensing Satellite (LCROSS) impacted a Centaur rocket stage into permanently shadowed region (PSR) in Cabeus crater, excavating water ice other volatiles. We used the Miniature Radio Frequency (Mini‐RF) instrument on Reconnaissance Orbiter ShadowCam Korean Pathfinder to detect probable 22‐m diameter crater that resulted from LCROSS impact. formed superposed upon dense small population along ray larger pre‐existing crater. From its geologic context,...
Abstract Various active and passive orbital measurements have provided evidence for surficial water ice within some lunar permanently shadowed regions (PSRs), especially from near-infrared observations by the M 3 instrument. However, radar identification of has so far remained ambiguous. Here, we examine radar-inferred dielectric properties PSRs illuminated craters to investigate potential ice. We show that permittivity proposed ice-bearing is lower a different distribution than crater...
Abstract We identified a ∼31 km diameter caldera with well‐developed ring fault and dike structure at the Gardner shield volcano. Using Chandrayaan‐1 Moon Mineralogy Mapper (M 3 ) Lunar Reconnaissance Orbiter (LRO) Diviner data, we investigated 15 effusive flow units an explosive unit. Spectral analysis revealed compositional similarities between eruptions, indicating single sourced magmatic eruption. Detailed hyperspectral multispectral analyses (visible, near‐infrared, thermal infrared,...
Late accretion of a "veneer" compositionally diverse planetesimals may introduce chemical heterogeneity in the mantles terrestrial planets. The size late veneer objects is an important control on angular momenta, eccentricities, and inclinations planets, but current estimates range from meter-scale bodies to with diameters thousands kilometers. We use three-dimensional global Monte Carlo model impact cratering, excavation, ejecta blanket formation show that evidence mantle can be preserved...
Abstract The water uptake and release by perchlorate salts have been well studied since the first in situ identification of such Martian soil Phoenix mission 2008. However, there few studies on effect insoluble regolith minerals interaction with vapor. In this work, we investigate impact a Mars‐relevant mineral, montmorillonite, Mars analog, Mojave Simulant (MMS), deliquescence (transition from dry crystalline to aqueous via vapor absorption), ice formation, efflorescence loss water) pure...