A5086074623- Astro and Planetary Science
- Planetary Science and Exploration
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Astronomy and Astrophysical Research
- Isotope Analysis in Ecology
- Geomagnetism and Paleomagnetism Studies
- Space exploration and regulation
- Geological and Geochemical Analysis
- Scientific Research and Discoveries
- Geology and Paleoclimatology Research
- Global Energy and Sustainability Research
- Space Satellite Systems and Control
- Gamma-ray bursts and supernovae
- High-pressure geophysics and materials
- Astronomical Observations and Instrumentation
- Marine and environmental studies
- Galaxies: Formation, Evolution, Phenomena
- Spacecraft and Cryogenic Technologies
- Solar and Space Plasma Dynamics
- Paleontology and Stratigraphy of Fossils
- Methane Hydrates and Related Phenomena
- Numerical methods for differential equations
Southwest Research Institute
2015-2024
Scotch Whisky Research Institute
2024
Solar System Exploration Research Virtual Institute
2010-2015
Target (United States)
2015
Observatoire de la Côte d’Azur
1997-2005
Centre National de la Recherche Scientifique
2005
United States Naval Observatory
1990-2003
Armagh Observatory & Planetarium
1997
Osservatorio Astrofisico di Torino
1997
Queen's University
1994-1997
USNO-B is an all-sky catalog that presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,042,618,261 objects derived from 3,643,201,733 separate observations. The data were obtained scans of 7435 Schmidt plates taken the sky surveys during last 50 years. USNO-B1.0 believed to provide coverage, completeness down V = 21, 02 astrometric accuracy at J2000, 0.3 mag photometric up five colors, 85% distinguishing stars nonstellar objects. A...
We present a new symplectic algorithm that has the desirable properties of sophisticated but highly efficient numerical algorithms known as mixed variable (MVS) methods and that, in addition, can handle close encounters between objects. This technique is based on variant standard MVS methods, it handles by employing multiple time step technique. When bodies are well separated, speed whenever two suffer mutual encounter, for relevant recursively subdivided to whatever level required....
The zodiacal cloud is a thick circumsolar disk of small debris particles produced by asteroid collisions and comets. Here, we present model based on the orbital properties lifetimes comets asteroids, dynamical evolution dust after ejection. quantitatively constrained IRAS observations thermal emission, but also qualitatively consistent with other observations. We find that 85-95% observed mid-infrared emission from Jupiter-family (JFCs) $<$10% long period Asteroidal found to be at $<$10%....
Orbital integrations carried out for 4 billion years produced a disk of scattered objects beyond the orbit Neptune. Objects in this can be distinguished from Kuiper belt by greater range eccentricities and inclinations. This was formed simulations encounters with Neptune during early evolution outer solar system. After particles first encountered Neptune, show that about 1 percent survive age A currently containing as few ∼6 × 10 8 could supply all observed Jupiter-family comets. Two...
Numerical simulations of particles placed in orbital resonances the main asteroid belt show that typical dynamical lifetimes objects could become near-Earth asteroids or meteorites are only a few million years, with majority destroyed by being transferred to Jupiter-crossing orbits driven into sun. Particles fortuitously migrate terrestrial planet region may be pushed high-inclination but still dynamically eliminated on time scales ∼10 years. These shorter require reassessment our...
We study the orbital evolution of four giant planets our solar system in a gas disk. Our investigation extends previous works by Masset & Snellgrove and Morbidelli Crida, which focused on dynamics Jupiter-Saturn system. The only systems we found to reach steady state are those locked quadruple mean-motion resonance (i.e., each planet is with its neighbor). In total, six such configurations. For gas-disk parameters these configurations characterized negligible migration rate. After...
Orbital histories of ejecta from the terrestrial planets were numerically integrated to study their transfer Earth. The properties lunar and martian meteorites are consistent with a recurrent ejection small meteoroids as result impacts on parent bodies. Long-range gravitational effects, especially secular resonances, strongly influence orbits many meteoroids, increasing collision rates other sun. These effects collisional destruction in asteroid belt shortened time scales higher fluxes than...
Results are presented of integrations a representative sample thousands test bodies in the Kuiper belt for times up to age solar system. Using this survey, main regions dynamical stability (and instability) mapped out as function particles' semi-major axes, eccentricities, and inclinations. Much structure is shown be correlated with mean motion secular resonances. Weak instabilities confirmed capable producing an influx Neptune-approaching even on Gyr time scales. The also compared current...