- (101955) 1999 RQ36
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(101955) 1999 RQ36 
DesignationsMinor planet
categoryApollo Aphelion 1.356 AU Perihelion 0.897 AU Semi-major axis 1.126 AU Eccentricity 0.204 Orbital period 436.604 d (1.20 a) Mean anomaly 193.420° Inclination 6.035° Longitude of ascending node 2.068° Physical characteristicsMean radius ~280 m Albedo 0.03-0.06[3] Surface temp.
Kelvinmin mean max 371 (101955) 1999 RQ36 is an Apollo asteroid discovered by LINEAR in 1999. The asteroid is the planned target of the OSIRIS-REx mission which will return samples to Earth for further study.[4] It is listed on the Sentry Risk Table.[5]
It has a mean diameter of approximately 560 meters and has been observed extensively with the Arecibo Observatory Planetary Radar and the Goldstone Deep Space Network.[2][6][7]
A recent dynamical study by Andrea Milani and collaborators has located a series of eight potential Earth impacts between 2169 and 2199. The cumulative probability of impact is dependent on poorly known physical properties of the object, but is not higher than 0.07% for all eight encounters.[8] To accurately assess 1999 RQ36's probability of Earth impact will require a detailed shape model of the asteroid and additional observations (either from the ground or from spacecraft visiting the object) to determine the magnitude of the Yarkovsky acceleration.
Separately, 1999 RQ36 has been considered many times as the target of spacecraft missions, including OSIRIS-REx, due to the low delta-v[9] required to reach it from Earth orbit. NASA announced on May 25, 2011, that OSIRIS-REx had been selected as part of NASA's New Frontiers Program.[10] The spacecraft will launch in 2016, reach the asteroid in 2020 and return samples to Earth in 2023.
References
- ^ "The Shape and Spin of 101955 (1999 RQ36) from Arecibo and Goldstone Radar Imaging". http://adsabs.harvard.edu/abs/2007DPS....39.1306N.
- ^ a b "Goldstone Delay-Doppler Images of 1999 RQ36". Asteroid Radar Research. Jet Propulsion Laboratory. http://echo.jpl.nasa.gov/~lance/1999RQ36/1999RQ36.html.
- ^ Emery, J. P.; Fernández, Y. R.; Kelley, M. S.; Hergenrother, C. (2010). "Thermophysical Characterization of Potential Spacecraft Target (101955) 1999 RQ36". 41st Lunar and Planetary Science Conference 1533: 2282. Bibcode 2010LPI....41.2282E.
- ^ "NASA to Launch New Science Mission to Asteroid in 2016". NASA. http://www.nasa.gov/topics/solarsystem/features/osiris-rex.html. Retrieved 25 May 2011.
- ^ "Sentry Risk Table". NASA/JPL Near-Earth Object Program Office. 14 Oct 2011. http://neo.jpl.nasa.gov/risk/. Retrieved 2011-10-14.
- ^ Michael C. Nolan, Chris Magri, Lance Benner, et al., 2009, Radar observations of 1999 RQ36, in prep.
- ^ Hudson, R. S.; Ostro, S. J.; Benner, L. A. M.. "Recent Delay-Doppler Radar Asteroid Modeling Results: 1999 RQ36 and Craters on Toutatis". Bulletin of the American Astronomical Society (American Astronomical Society) 32: 1001. Bibcode 2000DPS....32.0710H.
- ^ Milani, Andrea; Chesley, Steven R.; Sansaturio, Maria Eugenia; Bernardi, Fabrizio; Valsecchi, Giovanni B.; Arratia, Oscar (2009). "Long term impact risk for (101955) 1999 RQ36". Icarus 203 (2): 460–471. Bibcode 2009Icar..203..460M. doi:10.1016/j.icarus.2009.05.029.
- ^ Near-Earth Asteroid Delta-V for Space Rendezvous
- ^ NASA to Launch New Science Mission to Asteroid in 2016.
External links
- Earth Impact Risk Summary: 101955 1999 RQ36 (Years: 2169-2199) - JPL near-Earth object website
- Orbit parameters - NASA website
- Temperature History and Dynamical Evolution of (101955) 1999 RQ 36: A Potential Target for Sample Return from a Primitive Asteroid (2011 ApJ 728 L42)
Categories:- Apollo asteroids
- Near-Earth asteroids
- Potential impact events caused by Near-Earth objects
- Astronomical objects discovered in 1999
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