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MRO’s 2.4-meter Telescope: A New Facility for Follow-up and Characterization of Near-Earth Objects. William H. Ryan and Eileen V. Ryan (MRO/NM Tech). Asteroid Belt. Collisions are a fundamental process in the solar system & are not yet well understood.
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MRO’s 2.4-meter Telescope: A New Facility for Follow-up and Characterization of Near-Earth Objects William H. Ryan and Eileen V. Ryan (MRO/NM Tech) AMOS 2008
Asteroid Belt • Collisionsare a fundamental process in the solar system & are not yet well understood. • Applications:planetary accretion, evolution of ring systems, evolution of the asteroid and Kuiper belts, planetary cratering, meteorite ejection and delivery, etc. • Also: Earth-Crossers(NEAs)are apotential hazard to the Earth if on impacting orbits. Locations of asteroids: April 8, 2003 AMOS 2008
Origin of NEAs: Resonance AMOS 2008
Kirkwood Gaps AMOS 2008
Objective: Find and Characterize PHAs • Need Search & Discovery Telescopes for Cataloging • Need Follow-up Telescopes for Orbit Refinement & Characterization-- Composition -- Internal Structure -- Size (Albedo) • Need Continual Surveying for Orbit Variations (i.e., first line of defense is know the enemy…) AMOS 2008
Trickier Example: 2007 WD5 Images were 2 minute exposures, over 1.5 hours (42 stacked images). Object was moving 0.25"/min & V~24. AMOS 2008
Time-resolved Photometry • Asteroids/satellites shine from reflected sunlight– proportional to cross-sectional area at small solar phase angles (0 is sun behind observer). • As the object rotates, the amount of light varies. • By measuring the light variation over time, we derive a rotation rateand constrain orientation & shape. Asteroid Ida (Rotation Images, Galileo Spacecraft) AMOS 2008
Direct Model Lightcurve Origin for doubly periodic behavior– reproduced even by irregular shapes. AMOS 2008
3782 Celle: 5 Jan 2003 AMOS 2008
3782 Celle Model AMOS 2008
NEO studies are now ‘Real Work’ at MRO! • Supported by: • NASA’s NEO Program • NM Tech R&ED • DOD funding that made MRO possible • September 6 - 7, 2008 - 1.5 nights • Astrometry – 7 targets ranging from V~18-22 • Color and time-series photometry on 2 targets AMOS 2008
NEOCP Object BL04704 6 - 7 Sept 2008 AMOS 2008
More Complex Lightcurve: 3155 Lee Ryan et al. 2000 Vesta Family Asteroid AMOS 2008
NEOCP BL04704 (K08R24Q) Higher Albedo S-type Assuming S-type G~0.23 D ~ 270 m (using pV = 0.2) AMOS 2008
Torino Hazard Scale: No Hazard Normal Meriting Attention by Astronomers Threatening Certain Collisions As of February 2008, 927 asteroids have been tagged as potentially hazardous. AMOS 2008