A5033595799- Astro and Planetary Science
- Planetary Science and Exploration
- Space Satellite Systems and Control
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Space Exploration and Technology
- Isotope Analysis in Ecology
- Space Science and Extraterrestrial Life
- Solar and Space Plasma Dynamics
- Spacecraft Design and Technology
- Geology and Paleoclimatology Research
- Spacecraft Dynamics and Control
- Spacecraft and Cryogenic Technologies
- Nuclear Physics and Applications
- Space exploration and regulation
- Inertial Sensor and Navigation
- Distributed systems and fault tolerance
- Geological and Geochemical Analysis
- earthquake and tectonic studies
- History and Developments in Astronomy
- Astrophysics and Star Formation Studies
- Radioactive contamination and transfer
- Astronomical Observations and Instrumentation
- Geomagnetism and Paleomagnetism Studies
- Astronomical and nuclear sciences
Jet Propulsion Laboratory
2015-2025
University of Central Florida
2021
Colorado School of Mines
2021
Sorbonne Université
2021
Centre National de la Recherche Scientifique
2021
Auburn University
2021
Lunar and Planetary Institute
2021
Massachusetts Institute of Technology
2021
Johns Hopkins University
2021
Johns Hopkins University Applied Physics Laboratory
2021
Hubble Space Telescope (HST) images reveal major atmospheric changes created by the collision of comet Shoemaker-Levy 9 with Jupiter. Plumes rose to 3000 kilometers ejection velocities on order 10 second -1 ; some plumes were visible in shadow Jupiter before rising into sunlight. During impacts, incoming bolide may have been detected. Impact times average about 8 minutes later than predicted. Atmospheric waves seen a wave front speed 454 ± 20 meters . The HST impact site evolution and record...
Abstract 1I/‘Oumuamua is the first confirmed interstellar body in our solar system. Here we report on observations of ‘Oumuamua made with Spitzer Space Telescope 2017 November 21–22 (UT). We integrated for 30.2 hr at 4.5 μ m (IRAC channel 2). did not detect object and place an upper limit flux 0.3 Jy (3 σ ). This implies effective spherical diameter less than [98, 140, 440] albedo greater [0.2, 0.1, 0.01] under assumption low, middle, or high thermal beaming parameter η , respectively. With...
Abstract Near-Earth Objects (NEOs) are a transient population of small bodies with orbits near or in the terrestrial planet region. They represent mid-stage dynamical cycle asteroids and comets, which starts their removal from respective source regions—the main belt trans-Neptunian scattered disk—and ends as impact planets, disintegrate Sun, ejected solar system. Here we develop new orbital model NEOs by numerically integrating asteroid main-belt sources calibrating results on observations...
Abstract– On October 7, 2008, asteroid 2008 TC 3 impacted Earth and fragmented at 37 km altitude above the Nubian Desert in northern Sudan. The area surrounding asteroid’s approach path was searched, resulting first recovery of meteorites from an observed space. This also remains a fragile “cometary” PE = IIIa/b type fireball. In subsequent searches, over 600 mostly small 0.2–379 g (named “Almahata Sitta”) with total mass 10.7 kg were recovered 30 × 7 area. Meteorites fell along track 1.3 −1...
Integration of the orbit asteroid (29075) 1950 DA, which is based on radar and optical measurements spanning 51 years, reveals a 20-minute interval in March 2880 when there could be nonnegligible probability 1-kilometer object colliding with Earth. Trajectory knowledge remains accurate until then because extensive astrometric data, an inclined geometry that reduces in-plane perturbations, uncertainty space modulated by gravitational resonance. The approach distance determined primarily...
Abstract— The newly discovered asteroid 2002 AA 29 moves in a very Earth‐like orbit that relative to Earth has unique horseshoe shape and allows transitions quasi‐satellite state. This is the first body known be simple heliocentric orbit, moving along its parent planet's orbit. It similarly also true co‐orbital object of Earth, since other asteroids 1:1 resonance with have orbits dissimilar from our planet. When quasi‐satellite, it remains within 0.2 AU for several decades. exhibit this...
The standard nongravitation force model has been modified by allowing the water-vaproization curve to peak a certain number of days (DT) either before or after perihelion, and modification is shown often improve data fit. best fit astrometric generally achieved for value DT corresponding offset in comet's visual light curve. asymmetric model, which more accurately mimics outgassing history, suggests only weakly that rotation direction Comet Halley direct, it does not provide evidence axis...
We describe the physical and orbital properties of C/2011 W3. After surviving perihelion passage, comet was observed to undergo major changes. The permanent loss nuclear condensation formation a narrow spine tail were first at Malargue, Argentina, on December 20 then systematically Siding Spring, Australia. process disintegration culminated with terminal fragmentation event 17.6 UT. postperihelion dust tail, for ∼3 months, product activity over <2 days. nucleus' breakup crumbling probably...
The June 2, 2018, impact of asteroid 2018 LA over Botswana is only the second detected in space prior to impacting land. Here, we report on successful recovery meteorites. Additional astrometric data refine approach orbit and define spin period shape asteroid. Video observations fireball constrain asteroid's position its were used triangulate location fireball's main flare Central Kalahari Game Reserve. 23 meteorites recovered. A consortium study eight these classifies Motopi Pan as a HED...
Observations of near-Earth asteroid 1998 KY26 shortly after its discovery reveal a slightly elongated spheroid with diameter about 30 meters, composition analogous to carbonaceous chondritic meteorites, and rotation period 10.7 minutes, which is an order magnitude shorter than that measured for any other solar system object. The too rapid consist multiple components bound together just by their mutual gravitational attraction. This monolithic object probably fragment derived from cratering...
Of the three major groups of comets approaching Sun to between 6 and 12 solar radii discovered with coronagraphs on board SOHO, we investigate Marsden Kracht groups. We call these "sunskirters" distinguish them from Kreutz system sungrazers. Our objective is understand origin, history, orbital evolution two The tendency for their members arrive at perihelion in pairs or clusters a result recent fragmentation. As fragments more massive precursor objects, Marsden- Kracht-group are mostly less...