A5027883175- Astro and Planetary Science
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Geology and Paleoclimatology Research
- Geomagnetism and Paleomagnetism Studies
- Methane Hydrates and Related Phenomena
- Geological and Geochemical Analysis
- earthquake and tectonic studies
- Space Exploration and Technology
- High-pressure geophysics and materials
- Stellar, planetary, and galactic studies
- Marine and environmental studies
- Geophysics and Gravity Measurements
- Particle accelerators and beam dynamics
- Spacecraft Design and Technology
- Space Satellite Systems and Control
- Isotope Analysis in Ecology
- Astrophysics and Star Formation Studies
- Space exploration and regulation
- Space Science and Extraterrestrial Life
- Astronomy and Astrophysical Research
- Archaeology and ancient environmental studies
- High-Velocity Impact and Material Behavior
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
Jet Propulsion Laboratory
2016-2025
California Institute of Technology
2006-2024
Laboratory for Atmospheric and Space Physics
2002-2007
University of Colorado Boulder
2001-2007
NASA Astrobiology Institute
2005
Washington University in St. Louis
2005
Brown University
1996-2003
John Brown University
1997-2002
University of Colorado System
2001
Arizona State University
1993-2000
It has been proposed that Jupiter's satellite Europa currently possesses a global subsurface ocean of liquid water. Galileo gravity data verify the is differentiated into an outer H 2 O layer about 100 km thick but cannot determine current physical state this (liquid or solid). Here we summarize geological evidence regarding extant ocean, concentrating on imaging data. We describe and assess nine pertinent lines evidence: impact morphologies, lenticulae, cryovolcanic features, pull‐apart...
Abstract Many outer solar system bodies are thought to harbor liquid water oceans beneath their ice shells. This article first reviews how such detected. We then discuss they maintained, when formed, and what the oceans' likely characteristics are. focus in particular on Europa, Ganymede, Callisto, Titan, Enceladus, for which there is direct evidence of subsurface oceans. also consider candidate ocean worlds as Pluto Triton.
Abstract The ocean in Jupiter's moon Europa may have redox balance similar to Earth's. On Earth, low‐temperature hydration of crustal olivine produces substantial hydrogen, comparable any potential flux from volcanic activity. Here we compare hydrogen and oxygen production rates the Earth system with fluxes Europa's ocean. Even without hydrothermal activity, water‐rock alteration causes 10 times smaller than become reducing for a brief epoch, example, after thermal‐orbital resonance ∼2 Gyr...
Jupiter's satellite Europa almost certainly hides a global saltwater ocean beneath its icy surface. Chemistry at the ice surface and ocean-rock interface might provide building blocks for life, NASA's Clipper mission will assess Europa's habitability.
Abstract The goal of NASA’s Europa Clipper mission is to assess the habitability Jupiter’s moon Europa. After entering Jupiter orbit in 2030, flight system will collect science data while flying past 49 times at typical closest approach distances 25–100 km. mission’s objectives are investigate Europa’s interior (ice shell and ocean), composition, geology; also search for characterize any current activity including possible plumes. be accomplished with a payload consisting remote sensing...
The ice‐covered world Europa—one of the four large Galilean satellites Jupiter—may be best place in solar system to look for currently existing life beyond Earth.
The prospect of a future soft landing on the surface Europa is enticing, as it would create science opportunities that could not be achieved through flyby or orbital remote sensing, with direct relevance to Europa's potential habitability. Here, we summarize lander concept, developed by our NASA-commissioned Science Definition Team. concept concentrates observations can best in situ examination from its surface. We discuss suggested objectives and investigations for mission, along model...
Abstract Geological investigations planned for the Europa Clipper mission will examine formation, evolution, and expression of geomorphic structures found on surface. Understanding geologic features, their any recent activity are key inputs in constraining Europa’s potential habitability. In addition to providing information about moon’s habitability, study is compelling itself. Here we provide a high-level, cross-instrument, cross-discipline overview within mission. fascinating collection...
Abstract Jupiter’s icy moon, Europa, harbors a subsurface liquid water ocean; the prospect of this ocean being habitable motivates further exploration moon with upcoming NASA Europa Clipper mission. Key among mission goals is comprehensive assessment moon’s composition, which essential for assessing Europa’s habitability. Through powerful remote sensing and in situ investigations, will explore composition surface subsurface, its tenuous atmosphere, local space environment surrounding moon....
The first images of Jupiter, Io, Europa, and Ganymede from the Galileo spacecraft reveal new information about Jupiter's Great Red Spot (GRS) surfaces Galilean satellites. Features similar to clusters thunderstorms were found in GRS. Nearby wave structures suggest that GRS may be a shallow atmospheric feature. Changes surface color plume distribution indicate differences resurfacing processes near hot spots on Io. Patchy emissions seen while Io was eclipse by Jupiter. outer margins prominent...
Images of Europa from the Galileo spacecraft show a surface with complex history involving tectonic deformation, impact cratering, and possible emplacement ice-rich materials perhaps liquids on surface. Differences in crater distributions suggest that some areas have been resurfaced more recently than others; could experience current cryovolcanic activity. Global-scale patterns features deformation resulting non-synchronous rotation around Jupiter. Some regions lithosphere fractured, icy...
Galileo data enable the major geological units, structures, and surface features to be identified on Europa. These include five primary units (plains, chaos, band, ridge, crater materials) their subunits, along with various tectonic structures such as faults. Plains are most widespread. Ridged plains material spans a wide range of ages, including oldest recognizable Europa, appears represent style resurfacing, rather than cryovolcanism. Smooth typically embays other terrains possibly type...
The surface of 243 Ida is dominated by the effects impacts. No complex crater morphologies are observed. A complete range degradation states present, which also reveals optical maturation (darkening and reddening materials with increasing exposure age). Regions bright material associated freshest craters might be ballistically emplaced deposits or result seismic disturbance loosely-bound materials. Diameter/depth ratios for fresh on ∼1:6.5, similar to Gaspra results, but greater than 1:5...
Global structural mapping of high-resolution Cassini images Enceladus reveals a richly varied surface. Most notable are three main regions deformation each containing multiple units. In addition to the well known "South Polar Terrain" (SPT), there two other large that we term "Leading Hemisphere (LHT) and "Trailing (THT). Each these terrains includes circumferential belt encloses one or more structurally deformed Areal extents range from about 80,000 km2 (SPT) 195,000 160 250 km equivalent...