101955 Bennu

From Infogalactic: the planetary knowledge core
(Redirected from (101955) 1999 RQ36)
Jump to: navigation, search
101955 Bennu
NASA 1999 RQ36.gif
Radar image of 101955 Bennu (courtesy Arecibo Observatory and JPL)[1][2]
Discovery
Discovery date 11 September 1999
Designations
MPC designation 101955
Pronunciation /bɛˈnuː/
Named after
 Bennu
1999 RQ36
Apollo
Orbital characteristics[3]
Epoch 1 January 2011 (JD 2455562.5)
Uncertainty parameter 0
Observation arc 13.36 yr (4880 days)
Aphelion 1.3559 AU (202.84 Gm)
Perihelion 0.89689 AU (134.173 Gm)
1.1264 AU (168.51 Gm)
Eccentricity 0.20375
1.20 yr (436.65 d)
101.7039°
Inclination 6.0349°
2.0609°
66.2231°
Earth MOID 0.0032228 AU (482,120 km)
Jupiter MOID 3.87795 AU (580.133 Gm)
Proper orbital elements[3][4]
0.21145
5.0415°
301.1345 deg / yr
1.19548 yr
(436.649 d)
Physical characteristics
Mean radius
 246 ± 10 m[1]
Equatorial radius
 275 ± 10 m[1]
Mass 6.0×1010 kg[5] to 7.76×1010 kg
Mean density
 1.26 ± 0.070 g/cm3
4.288 h (0.1787 d)
4.288 hours[3]
0.046[4]
Surface temp. min mean max
Kelvin[6] 236 259 279
Fahrenheit -34.6 6.8 42.8
Celsius -37 -14 6
B[4]
20.9

101955 Bennu (provisional designation 1999 RQ36)[7] is an Apollo asteroid discovered by the LINEAR Project on September 11, 1999. It is the planned target of the OSIRIS-REx mission which is intended to return samples to Earth in 2023 for further study.[8][9] It is a potential Earth impactor and is listed on the Sentry Risk Table with the third highest rating on the Palermo Technical Impact Hazard Scale.[10]

101955 Bennu has a mean diameter of approximately 492 m (1,614 ft; 0.306 mi) and has been observed extensively with the Arecibo Observatory Planetary Radar and the Goldstone Deep Space Network.[1][2][11]

Possible Earth impact

On average, an asteroid with a diameter of Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). can be expected to impact Earth about every 130,000 years or so.[12] A 2010 dynamical study by Andrea Milani and collaborators predicted a series of eight potential Earth impacts by Bennu between 2169 and 2199. The cumulative probability of impact is dependent on physical properties of Bennu that were poorly known at the time, but was not found to exceed 0.07% for all eight encounters.[13] The authors recognized that an accurate assessment of 101955 Bennu's probability of Earth impact would require a detailed shape model and additional observations (either from the ground or from spacecraft visiting the object) to determine the magnitude and direction of the Yarkovsky effect.

After the publication of the shape model and astrometry based on radar observations obtained in 1999, 2005, and 2011,[1] it was possible to estimate the Yarkovsky acceleration and to revise the impact assessment. The current (as of 2014) best estimate of the impact probability is a cumulative probability of 0.037% in the interval 2175 to 2196.[14] This corresponds to a score on the Palermo scale of −1.70.

Spacecraft missions

101955 Bennu has been considered a few times as the target of spacecraft missions due to the low Δv required to reach it from Earth orbit.[15] OSIRIS-REx mission of NASA's New Frontiers Program is planned to launch in 2016, reach 101955 Bennu in 2019 and return samples to Earth in 2023.[9]

Name

Bennu was named by Michael Puzio, a third-grader from North Carolina, one of more than eight thousand students from dozens of countries around the world who entered a "Name That Asteroid!" contest run by the University of Arizona, The Planetary Society, and the LINEAR Project, according to The Planetary Report, June 2013. Its name refers to the Egyptian mythological bird Bennu, which Puzio thought the spacecraft, OSIRIS-REx, including its TAGSAM arm, resembled.[16]

Gallery

  • Artist concept of OSIRIS-REx at asteroid Bennu.[17]

  • Illustration of OSIRIS-REx collecting a sample from asteroid Bennu.

  • Sample return capsule from the Stardust mission.

  • Asteroid Bennu is thought to contain materials present when the Solar System was first formed.

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Lua error in package.lua at line 80: module 'strict' not found.
  2. ↑ 2.0 2.1 Lua error in package.lua at line 80: module 'strict' not found.
  3. ↑ 3.0 3.1 3.2 Lua error in package.lua at line 80: module 'strict' not found.
  4. ↑ 4.0 4.1 4.2 Lua error in package.lua at line 80: module 'strict' not found.
  5. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  6. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  7. ↑ We have a winner! The OSIRIS-REx asteroid's name is: Bennu!
  8. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  9. ↑ 9.0 9.1 Lua error in package.lua at line 80: module 'strict' not found.
  10. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  11. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  12. ↑ Lua error in package.lua at line 80: module 'strict' not found. (solution using density of 2,600 kg/m^3, sped of 17km/s, and impact angle of 45 degrees)
  13. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  14. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  15. ↑ Near-Earth Asteroid Delta-V for Space Rendezvous
  16. ↑ Nine-Year-Old Names Asteroid Target of NASA Mission in Competition Run By The Planetary Society
  17. ↑ Lua error in package.lua at line 80: module 'strict' not found.

External links

Retrieved from "https://infogalactic.com/w/index.php?title=101955_Bennu&oldid=716143281"