A5011716349- Astro and Planetary Science
- Planetary Science and Exploration
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Isotope Analysis in Ecology
- Space Exploration and Technology
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Spacecraft and Cryogenic Technologies
- Nuclear Physics and Applications
- Atmospheric Ozone and Climate
- Geology and Paleoclimatology Research
- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Gamma-ray bursts and supernovae
- Methane Hydrates and Related Phenomena
- High-pressure geophysics and materials
- Scientific Research and Discoveries
- Space Satellite Systems and Control
- Earthquake Detection and Analysis
- Astronomical Observations and Instrumentation
- Laser-induced spectroscopy and plasma
- Astrophysical Phenomena and Observations
- Analytical Chemistry and Chromatography
University of Alabama
2024-2025
Southwest Research Institute
2015-2024
The University of Texas at San Antonio
2011-2022
Centre National de la Recherche Scientifique
2011-2021
Imperial College London
2021
Swedish Institute of Space Physics
2021
Université Toulouse III - Paul Sabatier
2021
Space Micro (United States)
2009-2019
Laboratoire de Planétologie et Géosciences
2018
Nantes Université
2018
The Cassini spacecraft passed within 168.2 kilometers of the surface above southern hemisphere at 19:55:22 universal time coordinated on 14 July 2005 during its closest approach to Enceladus. Before and after this time, a substantial atmospheric plume coma were observed, detectable in Ion Neutral Mass Spectrometer (INMS) data set out distance over 4000 from INMS indicate that are dominated by water, with significant amounts carbon dioxide, an unidentified species mass-to-charge ratio 28...
Titan's lower atmosphere has long been known to harbor organic aerosols (tholins) presumed have formed from simple molecules, such as methane and nitrogen (CH4 N2). Up now, it assumed that tholins were at altitudes of several hundred kilometers by processes yet unobserved. Using measurements a combination mass/charge energy/charge spectrometers on the Cassini spacecraft, we obtained evidence for tholin formation high (approximately 1000 kilometers) in atmosphere. The observed chemical mix...
Saturn's moon Enceladus has an ice-covered ocean; a plume of material erupts from cracks in the ice. The contains chemical signatures water-rock interaction between ocean and rocky core. We used Ion Neutral Mass Spectrometer onboard Cassini spacecraft to detect molecular hydrogen plume. By using instrument's open-source mode, background processes production instrument were minimized quantified, enabling identification statistically significant signal native Enceladus. find that most...
A series of recent measurements the outflow ionization from ionosphere have further heightened our awareness strength ionospheric source magnetospheric plasmas. In this paper contribution polar wind and cleft ion fountain at energies less than 10 eV has been added to previously measured sources; total then used calculate resulting density in different internal regions earth's magnetosphere: plasmasphere, plasma trough, sheet, magnetotail lobes. Using estimated volumes for these an residence...
The Cassini Ion Neutral Mass Spectrometer (INMS) has obtained the first in situ composition measurements of neutral densities molecular nitrogen, methane, hydrogen, argon, and a host stable carbon-nitrile compounds Titan's upper atmosphere. INMS mass spectrometry also provided evidence for atmospheric waves atmosphere direct isotopes carbon, which reveal interesting clues about evolution bulk thermal structure moon's do not appear to have changed considerably since Voyager 1 flyby.
Titan's ionosphere contains a rich positive ion population including organic molecules. Here, using CAPS electron spectrometer data from sixteen Titan encounters, we reveal the existence of negative ions. These ions, with densities up to ∼100 cm −3 , are in mass groups 10–30, 30–50, 50–80, 80–110, 110–200 and 200+ amu/charge. During one low encounter, ions per charge as high 10,000 amu/q seen. Due their unexpectedly at ∼950 km altitude, these must play key role chemistry they may be...
On 27 August 2016, the Juno spacecraft acquired science observations of Jupiter, passing less than 5000 kilometers above equatorial cloud tops. Images Jupiter's poles show a chaotic scene, unlike Saturn's poles. Microwave sounding reveals weather features at pressures deeper 100 bars, dominated by an ammonia-rich, narrow low-latitude plume resembling deeper, wider version Earth's Hadley cell. Near-infrared mapping relative humidity within prominent downwelling regions. Juno's measured...
Comets contain the best-preserved material from beginning of our planetary system. Their nuclei and comae composition reveal clues about physical chemical conditions during early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion Neutral Analysis) onboard Rosetta spacecraft has measured coma comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many rotation periods a wide range latitudes. These measurements...
Molecular nitrogen (N2) is thought to have been the most abundant form of in protosolar nebula. It main N-bearing molecule atmospheres Pluto and Triton probably reservoir from which giant planets formed. Yet comets, often considered primitive bodies solar system, N2 has not detected. Here we report direct situ measurement Jupiter family comet 67P/Churyumov-Gerasimenko, made by Rosetta Orbiter Spectrometer for Ion Neutral Analysis mass spectrometer aboard spacecraft. A N2/CO ratio (5.70 ±...
The origin of cometary matter and the potential contribution comets to inner-planet atmospheres are long-standing problems. During a series dedicated low-altitude orbits, Rosetta Orbiter Spectrometer for Ion Neutral Analysis (ROSINA) on spacecraft analyzed isotopes xenon in coma comet 67P/Churyumov-Gerasimenko. isotopic composition shows deficits heavy matches that primordial atmospheric component. present-day Earth atmosphere contains 22 ± 5% xenon, addition chondritic (or solar) xenon.
ABSTRACT Comets are considered to be some of the most pristine and unprocessed Solar system objects accessible in situ exploration. Investigating their molecular elemental composition takes us on a journey back early period our possibly even further. In this work, we deduce bulk abundances major volatile species comet 67P/Churyumov-Gerasimenko, target European Space Agency’s (ESA) Rosetta mission. The basis measurements obtained with ROSINA instrument suite board orbiter during suitable high...
Abstract Enceladus’s long-lived plume of ice grains and water vapor makes accessing oceanic material readily achievable from orbit (around Saturn or Enceladus) the moon’s surface. In preparation for National Academies Sciences, Engineering Medicine 2023–2032 Planetary Science Astrobiology Decadal Survey, we investigated four architectures capable collecting analyzing and/or on surface to address most pressing questions at Enceladus: Is subsurface ocean inhabited? Why, why not? Trades...
Abstract The MAss Spectrometer for Planetary EXploration (MASPEX) is a high-mass-resolution, high-sensitivity, multi-bounce time-of-flight mass spectrometer (MBTOF) capable of measuring minor species with abundances sub-parts-per-million in Europa’s sputter-produced and radiolytically modified exosphere its oceanic plumes. goal the MASPEX-Europa investigation to determine, through in-situ measurement plume composition, whether conditions habitability exist or have existed on Europa. As...
Abstract Juno's highly eccentric polar orbit takes it to perijove distances of 1.06 on each orbit. For the first perijove, this occurred just north jovigraphic equator, but has precessed by about a degree per over mission. Minimum altitudes vary from 3,200–8,000 km through The Waves instrument observes number plasma wave modes in and near non‐auroral ionosphere that provide information local electron density, including oscillations occur at frequency whistler‐mode hiss which an upper limit...
The theta aurora is a remarkable configuration of auroral and polar cap luminosities for which generally sun‐aligned transpolar arc extends contiguously from the dayside to nightside sectors oval. Four individual occurrences over earth's northern hemisphere are examined in detail with global imaging instrumentation on board high‐altitude, polar‐orbiting spacecraft DE 1. Simultaneous measurements fields plasmas this high‐altitude its low‐altitude, companion, 2, order establish an overview...