M. Al Asad
A5035234721- Astro and Planetary Science
- Planetary Science and Exploration
- Geomagnetism and Paleomagnetism Studies
- Isotope Analysis in Ecology
- High-pressure geophysics and materials
- Nuts composition and effects
- Gamma-ray bursts and supernovae
- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Landslides and related hazards
- Nuclear Physics and Applications
- earthquake and tectonic studies
- Pulsars and Gravitational Waves Research
- Orthopedic Infections and Treatments
- Traumatic Ocular and Foreign Body Injuries
- Stellar, planetary, and galactic studies
- Livestock and Poultry Management
- Metallurgy and Cultural Artifacts
- Remote Sensing and LiDAR Applications
- Image and Object Detection Techniques
- Pacific and Southeast Asian Studies
- Urban and spatial planning
Planetary Science Institute
2020-2024
Brown University
2023-2024
University of California, Berkeley
2021-2024
University of British Columbia
2014-2023
University of Arizona
2020
Saudi Aramco (Saudi Arabia)
2015
Geisinger Medical Center
2013
Abstract During its approach to asteroid (101955) Bennu, NASA’s Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft surveyed Bennu’s immediate environment, photometric properties, rotation state. Discovery of a dusty natural satellite, or unexpected characteristics would have had consequences for the mission’s safety observation strategy. Here we show that observations during this period were highly sensitive satellites (sub-meter...
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...
Heterogeneous thermal properties of Bennu are due primarily to spatial mixing two boulder types with differing strengths.
Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) near-Earth asteroid (101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their texture. Space weathering Bennu materials does not simply progress from red (or vice versa). Instead, freshly exposed, redder surfaces initially...
Abstract The exploration of near‐Earth asteroids has revealed dynamic surfaces characterized by mobile, unconsolidated material that responds to local geophysical gradients, resulting in distinct morphologies and boulder distributions. OSIRIS‐REx (Origins, Spectral Interpretation, Resource Identification, Security‐Regolith Explorer) mission confirmed asteroid (101955) Bennu is a rubble pile with an surface dominated boulders. In this work, we documented indicative mass movement on assessed...
Abstract Accurate knowledge of Mercury's magnetospheric magnetic field is required to understand the sources planet's internal field. We present first model confined within a magnetopause shape derived from Magnetometer observations by MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft. The origin approximated dipole magnitude 190 nT R M 3 , where radius, offset northward 479 km along spin axis. External include currents flowing on boundary in cross‐tail current sheet....
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...
We investigate the shape of near-Earth asteroid (101955) Bennu by constructing a high-resolution (20 cm) global digital terrain model from laser altimeter data. By modeling northern and southern hemispheres separately, we find that longitudinal ridges previously identified in north extend into south but are obscured there surface material. In south, more numerous large boulders effectively retain materials imply higher average strength at depth to support them. The has fewer evidence boulder...
Abstract The surface of the rubble‐pile asteroid (101955) Bennu has been characterized in detail by OSIRIS‐REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) mission. By examining global local digital terrain models, we observed that possesses terraces, is, a series roughly latitude‐parallel, step‐like slope breaks. These partially circumscribe poles extend east‐west over several longitudinal quadrants at mid‐ to high (≥30°) latitudes. terraces...
OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) is a NASA mission to return sample of asteroid (101955) Bennu. Photometric modeling Bennu's surface key element both site characterization our broader scientific understanding the asteroid. heterogeneous presents substantial variation in reflectance produces scattered dataset that poses challenge photometric modeling. We show resolution shape model with which we calculate angles strongly...
Abstract We created high-resolution shape models of Phobos and Deimos using stereophotoclinometry united images from Viking Orbiter, 2, Mars Global Surveyor, Express, Reconnaissance Orbiter into a single coregistered collection. The best-fit ellipsoid to the model has radii (12.95 ± 0.04) km × (11.30 (9.16 0.03) km, with an average radius (11.08 km. (8.04 0.08) (5.89 0.06) (5.11 0.05) (6.27 0.07) new offer substantial improvements in resolution over existing models, while remaining globally...
Mercury's magnetosphere is known to be affected by enhanced ram pressures and magnetic fields inside interplanetary coronal mass ejections (ICMEs). Here we report detailed observations of an ICME compressing dayside the surface. A fast CME launched from Sun on November 29 2013 impacted first MESSENGER, which was orbiting Mercury, 30 later STEREO-A near 1 AU December 1. Following impact, MESSENGER remained in solar wind as spacecraft traveled inwards northwards towards surface until it...
Abstract NASA’s OSIRIS-REx mission to asteroid (101955) Bennu relied on the production of real-time shape models for both spacecraft navigation and scientific analysis. The primary method constructing during early phases was image-based stereophotoclinometry (SPC). SPC were used operational planning, navigation, sample site selection, initial investigations. To this end, detailed analyses quality each model a thorough documentation all sources error vital ensure proper considerations...
Abstract The sample of asteroid (101955) Bennu was collected from the Nightingale site by Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer spacecraft arrived on Earth 24 September 2023. To better understand Bennu's parent body, we identified boulders over 2 m in diameter around region analyzed normal albedo, morphology, surface roughness. We found that can be separated into two groups based four using morphology including angularity, texture, presence...
Abstract The OSIRIS-REx spacecraft collected a surface sample from Hokioi crater (55.8° N, 42.3° E; diameter ∼20 m) on the asteroid Bennu in 2020 October. We explore geology of collection site, known as Nightingale, by using digital terrain models, relative albedo maps, and images spacecraft. sits at northwest edge an older, larger (120 m diameter) between two north–south ridges respectively located roughly 0° 90° longitude, which unconsolidated material generally migrates geopotential high...