A5038033848- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Planetary Science and Exploration
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Isotope Analysis in Ecology
- Spacecraft and Cryogenic Technologies
- Gamma-ray bursts and supernovae
- Economic Growth and Productivity
- Space Exploration and Technology
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Hydrocarbon exploration and reservoir analysis
- Calibration and Measurement Techniques
- High-pressure geophysics and materials
- High Altitude and Hypoxia
- Distributed and Parallel Computing Systems
- Technology Assessment and Management
- Geophysics and Gravity Measurements
- Environmental and Biological Research in Conflict Zones
- Solar and Space Plasma Dynamics
Franklin W. Olin College of Engineering
2020-2021
California Institute of Technology
2013-2018
Infrared Processing and Analysis Center
2015-2018
Jet Propulsion Laboratory
2013-2015
Space Information Laboratories (United States)
2014-2015
University of California, Los Angeles
2012-2013
Earth and Space Research
2013
NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft has been brought out of hibernation and resumed surveying the sky at 3.4 4.6 um. The scientific objectives NEOWISE reactivation mission are to detect, track, characterize near-Earth asteroids comets. search for minor planets on December 23, 2013, first new object (NEO) was discovered six days later. As an infrared survey, detects based their thermal emission is equally sensitive high low albedo objects; consequently,...
The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and Scattered Disk Objects in the thermal infrared, including 15 discoveries that were new. We present analyses of these observations to estimate sizes mean optical albedos. find albedos 0.08 +/- 0.04 for entire data set. Thermal fits yield average beaming parameters 0.9 0.2 are similar both SDO Centaur sub-classes. Biased cumulative size distributions size-frequency distribution power law indices ~ -1.7 0.3. also reveal a...
We present revised near-infrared albedo fits of 2835 main-belt asteroids observed by WISE/NEOWISE over the course its fully cryogenic survey in 2010. These are derived from reflected-light images taken simultaneously with thermal emission measurements, allowing for more accurate measurements albedos than is possible visible measurements. Because our sample requires reflected light it undersamples small, low-albedo asteroids, as well those blue spectral slopes across wavelengths investigated....
Abstract For minor planet observations to be archived and used by the scientific community, of individual objects must linked together into groups called tracklets. This linking is nontrivial, as software find real tracklets in noisy data within a reasonable amount time. We describe FindPOTATOs, written Python that can assemble With appropriate parameters, FindPOTATOs assembles for variety objects, including close-approaching near-Earth trans-Neptunian objects. ideal processing sets taken at...
Using albedos from WISE/NEOWISE to separate distinct albedo groups within the Main Belt asteroids, we apply Hierarchical Clustering Method these subpopulations and identify dynamically associated clusters of asteroids. While this survey is limited ∼35% known asteroids that were detected by NEOWISE, present families linked objects as higher confidence associations than can be obtained dynamical linking alone. We find over one-third observed population represented in high-confidence cores...
We present preliminary diameters and albedos for 13511 MBAs that were observed during the 3-Band Cryo phase of WISE survey (after outer cryogen tank was exhausted) as part NEOWISE Post-Cryo Survey inner exhausted). With a reduced or complete loss sensitivity in two long wavelength channels WISE, uncertainty our fitted is increased to ~20% diameter ~40% albedo. Diameter fits using only 3.4 4.6 um are shown be dependent on literature optical H absolute magnitudes. These data allow us increase...
We present updated/new thermal model fits for 478 Jovian Trojan asteroids observed with the Wide-field Infrared Survey Explorer (WISE). Using fact that two shortest bands used by WISE, centered on 3.4 and $4.6\mu$m, are dominated reflected light, we derive albedos of a significant fraction these objects in bands. While visible both C-, P- D-type strikingly similar, WISE data reveal albedo at $3.4\mu$m is different between C-/P- D-types. The 3.4$\mu$m can be thus to classify objects,...
We present preliminary diameters and albedos for 7,959 asteroids detected in the first year of NEOWISE Reactivation mission. 201 are near-Earth (NEAs). 7,758 Main Belt or Mars-crossing asteroids. 17% these objects have not been previously characterized using WISE thermal measurements. Diameters determined to an accuracy ~20% better. If good-quality H magnitudes available, can be within ~40%
The Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) mission continues to detect, track, and characterize minor planets. We present diameters albedos calculated from observations taken during the second year since spacecraft was reactivated in late 2013. These include 207 near-Earth asteroids 8,885 other asteroids. $84\%$ of did not have previously measured by NEOWISE mission. Comparison sizes measurements with those occultations, spacecraft, radar-derived shapes shows...
We have identified and quantified semimajor axis drifts in near-Earth asteroids (NEAs) by performing orbital fits to optical radar astrometry of all numbered NEAs. focus on a subset 54 NEAs that exhibit some the most reliable strongest drift rates. Our selection criteria include Yarkovsky sensitivity metric quantifies detectability any given data set, signal-to-noise metric, coverage requirements. In 42 cases, observed (∼10−3 AU Myr−1) agree well with numerical estimates drifts. This...
We present the preliminary results of an analysis sub-populations within near-Earth asteroids, including Atens, Apollos, Amors, and those that are considered potentially hazardous using data from Wide-field Infrared Survey Explorer (WISE). In order to extrapolate sample objects detected by WISE greater population, we determined survey biases for asteroids project's automated moving object processing system (known as NEOWISE) a function diameter, visible albedo, orbital elements. Using this...
The 163 comets observed during the WISE/NEOWISE prime mission represent largest infrared survey to date of comets, providing constraints on dust, nucleus size, and CO + CO2 production. We present detailed analyses comet discoveries, discuss observations active showing 4.6 μm band excess. find a possible relation between dust production, as well differences in sizes long short period nuclei.
Abstract We use NEOWISE data from the four-band and three-band cryogenic phases of Wide-field Infrared Survey Explorer mission to constrain size distributions comet populations debias measurements short- long-period (LPC) populations. find that fit debiased LPC population yields a cumulative size−frequency distribution (SFD) power-law slope ( β ) −1.0 ± 0.1, while Jupiter-family (JFC) SFD has steeper with = −2.3 0.2. The JFCs in our sample yielded mean nucleus 1.3 km diameter, LPCs’ is...
Enhancements to the science data processing pipeline of NASA's Wide-field Infrared Survey Explorer (WISE) mission, collectively known as NEOWISE, resulted in detection >158,000 minor planets four infrared wavelengths during fully cryogenic portion mission. Following depletion its cryogen, Planetary Science Directorate funded a four-month extension complete survey inner edge Main Asteroid Belt and detect discover near-Earth objects (NEOs). This extended phase, NEOWISE Post-Cryogenic Survey,...
Only a very small fraction of the asteroid population at size scales comparable to object that exploded over Chelyabinsk, Russia has been discovered date, and physical properties are poorly characterized. We present previously unreported detections 106 close approaching near-Earth objects (NEOs) by Wide-field Infrared Survey Explorer mission's NEOWISE project. These infrared observations constrain such as diameter albedo for these objects, many which found be smaller than 100 m. Because...
The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) reactivation mission has completed its third year of surveying the sky in thermal infrared for near-Earth asteroids and comets. NEOWISE collects simultaneous observations at 3.4 um 4.6 solar system objects passing through field regard. These data allow determination total emission from bodies inner system, thus sizes these objects. In this paper we present model fits asteroid diameters 170 NEOs 6110 MBAs detected during...
We have created a new image analysis pipeline to reprocess images taken by the Near Earth Asteroid Tracking survey and applied it ten nights of observations. This work is first large-scale reprocessing from an asteroid discovery in which thousands archived are re-calibrated, searched for minor planets, resulting observations reported Minor Planet Center. describe software used extract, calibrate, clean sources images, including specific techniques that accommodate unique features these...
The Euphrosyne asteroid family is uniquely situated at high inclination in the outer Main Belt, bisected by nu_6 secular resonance. This large, low albedo may thus be an important contributor to specific subpopulations of near-Earth objects. We present simulations orbital evolution members from time breakup day, focusing on those that move into orbits. find typically evolve a region element-space, with semimajor axes near ~3 AU, inclinations, very large eccentricities, and Tisserand...
Abstract The only Halley-type comet discovered by the Wide-Field Infrared Survey Explorer ( WISE ), C/2010 L5 was imaged three times , and it showed a significant dust tail during second third visits (2010 June July, respectively). We present here an analysis of data collected putting estimates on comet’s size, production rate, gas (CO+CO 2 ) active fraction. also detailed description novel tail-fitting technique that allows commonly used syndyne–synchrone models to be analytically, thereby...
Automated asteroid detection routines set requirements on the number of detections, signal-to-noise ratio, and linearity expected motion in order to balance completeness, reliability, time delay after data acquisition when identifying moving object tracklets. However, full-frame from a survey are archived, they can be searched later for asteroids that were below initial thresholds. We have conducted such search first three years reactivated NEOWISE data, looking near-Earth objects discovered...
The 163 comets observed during the WISE/NEOWISE prime mission represent largest infrared survey to date of comets, providing constraints on dust, nucleus sizes, and CO+CO2 production. We present detailed analyses comet discoveries, discuss observations active showing 4.6 $μ$m band excess. find a possible relation between dust production, as well differences in sizes long short period nuclei.