(101955) 1999 RQ36

(101955) 1999 RQ₃₆

Radar image of 1999 RQ36, courtesy Arecibo Observatory and JPL.[1][2]
Designations
Minor planet category	Apollo
Orbital characteristics
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 characteristics
Mean radius	~280 m
Albedo	0.03-0.06[3]
Surface temp.    Kelvin	min mean max 371

Although its composition is unknown, scientists think asteroid 1999 RQ₃₆ is made up of materials present when the solar system formed.

(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 Δv^[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

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)

v t e Impact cratering on Earth Geology Lists Worldwide Africa Antarctica Asia Australia Europe North America South America by country Confirmed ≥20 km diameter Acraman Amelia Creek Araguainha Beaverhead Boltysh Carswell Charlevoix Chesapeake Bay Chicxulub Clearwater East & West Gosses Bluff Haughton Kamensk Kara Karakul Keurusselkä Lappajärvi Logancha Manicouagan Manson Mistastin Mjølnir Montagnais Morokweng Nördlinger Ries Obolon' Popigai Presqu'île Puchezh-Katunki Rochechouart Saint Martin Shoemaker Siljan Slate Islands Steen River Strangways Sudbury Tookoonooka Vredefort Woodleigh Yarrabubba Topics Alvarez hypothesis breccia coesite complex crater cryptoexplosion ejecta blanket impact crater impact structure impactite Cretaceous–Paleogene boundary Late Heavy Bombardment lechatelierite meteorite moldavite planar deformation features shatter cone shock metamorphism shocked quartz stishovite suevite tektite Research Baldwin, Ralph Belknap Barringer, Daniel Barringer Medal Chao, Edward C T Dietz, Robert S Earth Impact Database Hartmann, William K Impact Field Studies Group Lunar and Planetary Institute Melosh, H Jay Ryder, Graham Schultz, Peter H Shoemaker, Eugene Traces of Catastrophe book Astronomy Observation Catalina Sky Survey Earth-crosser asteroid impact event LINEAR LONEOS meteoroid Meteoritical Society NASA NEAT Near-Earth Object (NEO) NEOSSat Orbit@home Palermo Scale Pan-STARRS planetary science potentially hazardous object Sentry Spacewatch Torino Scale WISE Defense Asteroid-impact avoidance B612 Foundation Gravity tractor Ion Beam Shepherd NEOShield Spaceguard Potential threats 99942 Apophis 1950 DA 1999 RQ36 2004 VD17 2007 VK184 2011 AG5