A5067285842- Astro and Planetary Science
- Planetary Science and Exploration
- Space Exploration and Technology
- Space Satellite Systems and Control
- Geology and Paleoclimatology Research
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Experimental and Theoretical Physics Studies
- Stellar, planetary, and galactic studies
- Nuclear Physics and Applications
- High-pressure geophysics and materials
- Cryospheric studies and observations
- Isotope Analysis in Ecology
- Graphite, nuclear technology, radiation studies
- Nuts composition and effects
- Satellite Image Processing and Photogrammetry
- Nuclear physics research studies
- Arctic and Antarctic ice dynamics
- Distributed and Parallel Computing Systems
- Spacecraft and Cryogenic Technologies
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Spacecraft Dynamics and Control
- Calibration and Measurement Techniques
Jet Propulsion Laboratory
2021-2024
University of Colorado Boulder
2017-2023
NOAA National Centers for Environmental Information
2023
National Oceanic and Atmospheric Administration
2023
Cooperative Institute for Research in Environmental Sciences
2023
University of Colorado System
2019
University of Ottawa
2018
Universities Space Research Association
1994
Active asteroids are those that show evidence of ongoing mass loss. We report repeated instances particle ejection from the surface (101955) Bennu, demonstrating it is an active asteroid. The events were imaged by OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) spacecraft. For three largest observed events, we estimated ejected velocities sizes, event times, source regions, energies. also determined trajectories photometric properties...
The gravity field of a small body provides insight into its internal mass distribution. We used two approaches to measure the rubble-pile asteroid (101955) Bennu: (i) tracking and modeling spacecraft in orbit about (ii) pebble-sized particles naturally ejected from Bennu's surface sustained orbits. These yield statistically consistent results up degree order 3, with particle-based being significant 9. Comparisons constant-density shape model show that Bennu has heterogeneous deviations can...
Abstract We analyze the trajectories of 313 particles seen in near‐Bennu environment between December 2018 and September 2019. Of these, 65% follow suborbital trajectories, 20% undergo more than one orbital revolution around asteroid, 15% directly escape on hyperbolic trajectories. The median lifetime these is ∼6 hr. are sensitive to Bennu's gravitational field, which allows us reliably estimate spherical harmonic coefficients through degree 8 resolve nonuniform mass distribution 3....
Small bodies such as the near-Earth asteroid Bennu drift in their orbit due to thermal radiation forces (the Yarkovsky effect). Ground-based observations have indicated a nonzero probability of impacting Earth, depending on how its evolves. Thus, among goals OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) mission were precisely measure effect refine impact hazard assessment for this body. Here we address these objectives. Using...
Abstract Near‐Earth asteroid (101955) Bennu is an active experiencing mass loss in the form of ejection events emitting up to hundreds millimeter‐ centimeter‐scale particles. The close proximity Origins, Spectral Interpretations, Resource Identification, and Security–Regolith Explorer spacecraft enabled monitoring particles for a 10‐month period encompassing Bennu's perihelion aphelion. We found 18 multiparticle events, with masses ranging from near zero grams (or thousands uncertainties)...
Binary near-Earth asteroid (65803) Didymos is the target of proposed NASA Double Asteroid Redirection Test (DART), part Impact & Deflection Assessment (AIDA) mission concept. In this mission, DART spacecraft planned to impact secondary body Didymos, perturbing mutual dynamics system. The primary currently rotating at a spin period close barrier asteroids, and materials ejected from due are likely reach primary. These conditions may cause reshape, landslides, or internal deformation, changing...
Abstract Binary asteroids represent an important aspect of the dynamical evolution small bodies and may provide insight into evolutionary history these populations as a whole. Many past studies have focused on Yarkovsky–O’Keefe–Radzievskii–Paddack-driven spinup disruption pathway for binary formation in inner solar system. While shown likelihood that such process occurred, they are generally limited by assumptions simplifications their dynamics models. In this study we apply high-fidelity...
Volcanic plumes on Io have been observed during every spacecraft encounter from Voyager to Juno. The material within the plume ejecta provides direct insight into Io's composition in form of volcanic gases and pyroclastic grains. Return these materials would provide a window origins represent next logical step sample return, exploration Jupiter system. Prometheus Sample mission concept proposes collect sample, supported by remote observations scientific context.The can be tailored either...
Abstract The Geostationary Operational Environmental Satellite (GOES)-18, the latest spacecraft from NOAA GOES-R satellite series, was launched March 1, 2022. As with previous GOES-16 and GOES-17 satellites, GOES-18 monitors sources of space weather on Sun its effects at Earth. uses GOES data as part national forecasts, warnings alerts to many customers. hosts new magnetometers called Goddard (GMAG) that replace those (called MAG) built by a different vendor GOES-17. Like other GMAG provides...
Current American education is comprised of and influenced by a myriad complex legislative, technological, cultural representations consumption, however this historic-educational study specifically examines how the Reagan administration discursively initiated consumerizing educational framework. While existing research studies neoliberal implications on education, addresses reforms under President within discursive paradigm its impact. By using Critical Discourse Analysis selection...