101955 Bennu
101955 Bennu (provisional designation 1999 RQ36) is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999.
 Mosaic image of Bennu consisting of 12 PolyCam images collected on 2 December 2018 by OSIRIS-REx from a range of 24 km (15 mi). | |||||||||||||||||
| Discovery[1] | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Discovered by | LINEAR | ||||||||||||||||
| Discovery site | Lincoln Lab's ETS | ||||||||||||||||
| Discovery date | 11 September 1999 | ||||||||||||||||
| Designations | |||||||||||||||||
| MPC designation | (101955) Bennu | ||||||||||||||||
| Pronunciation | /bɛˈnuː/ | ||||||||||||||||
Named after | Bennu | ||||||||||||||||
| 1999 RQ36 | |||||||||||||||||
| Apollo · NEO · PHA | |||||||||||||||||
| Orbital characteristics[1] | |||||||||||||||||
| Epoch 31 July 2016 (JD 2457600.5) | |||||||||||||||||
| Uncertainty parameter 0 | |||||||||||||||||
| Observation arc | 13.36 yr (4880 days) | ||||||||||||||||
| Aphelion | 1.3559 au[convert: %s]%s | ||||||||||||||||
| Perihelion | 0.89689 au[convert: %s]%s | ||||||||||||||||
| 1.1264 au[convert: %s]%s | |||||||||||||||||
| Eccentricity | 0.20375 | ||||||||||||||||
| 1.20 yr (436.65 d) | |||||||||||||||||
Average orbital speed | 28.0 km/s (63,000 mph) | ||||||||||||||||
| 101.7039° | |||||||||||||||||
| 0° 49m 28.056s / day | |||||||||||||||||
| Inclination | 6.0349° | ||||||||||||||||
| 2.0609° | |||||||||||||||||
| 66.2231° | |||||||||||||||||
| Earth MOID | 0.0032228 au[convert: %s]%s | ||||||||||||||||
| Venus MOID | 0.194 au[convert: %s]%s[2] | ||||||||||||||||
| Mars MOID | 0.168 au[convert: %s]%s[2] | ||||||||||||||||
| Jupiter MOID | 3.877 au[convert: %s]%s | ||||||||||||||||
| TJupiter | 5.525 | ||||||||||||||||
| Proper orbital elements[3] | |||||||||||||||||
Proper eccentricity | 0.21145 | ||||||||||||||||
Proper inclination | 5.0415° | ||||||||||||||||
Proper mean motion | 301.1345 deg / yr | ||||||||||||||||
Proper orbital period | 1.19548 yr (436.649 d) | ||||||||||||||||
| Physical characteristics[6] | |||||||||||||||||
| Dimensions | 282.37 × 268.05 × 249.25 ± 0.06 m | ||||||||||||||||
Mean radius | 245.03±0.08 m | ||||||||||||||||
Equatorial radius | 282.37±0.06 m | ||||||||||||||||
Polar radius | 249.25±0.06 m | ||||||||||||||||
| 0.782±0.004 km2 | |||||||||||||||||
| Volume | 0.0615±0.0001 km3 | ||||||||||||||||
| Mass | (7.329±0.009)×1010 kg | ||||||||||||||||
Mean density | 1.190±0.013 g/cm3 | ||||||||||||||||
Equatorial surface gravity | 6 micro-g[4] | ||||||||||||||||
| 4.296057±0.000002 h | |||||||||||||||||
| 177.6±0.11° | |||||||||||||||||
North pole right ascension | +85.65±0.12° | ||||||||||||||||
North pole declination | −60.17±0.09° | ||||||||||||||||
| 0.044±0.002 | |||||||||||||||||
| |||||||||||||||||
| B[1][6] F[7] | |||||||||||||||||
| 20.9 | |||||||||||||||||
Bennu has a 1 in 2,700 chance of hitting Earth between the year 2175 and 2199.
It is named after the Bennu, the ancient Egyptian mythological bird associated with the Sun, creation, and rebirth.
Bennu has an average diameter of 492 metres (1,614 feet).
Bennu was the target of the OSIRIS-REx mission which returned samples to Earth in 2023 for further study.
Bennu is the second-highest on the cumulative rating on the Palermo technical impact hazard scale.
It is believed that Bennu broke off from another asteroid in the asteroid belt, but the gravitational pull of Saturn dislodged it into the range of Earth.
Bennu orbits the Sun every 1.2 years. It comes within 0.002 astronomical units of the earth every 6 years.
Some believe that if Bennu enters a specific hole between the earth and the moon its orbit could change in a way that would make it likely to hit Earth.
101955 Bennu Media
Series of Goldstone radar images in 1999 showing Bennu's rotation.
Bennu rotation PolyCam 2018-12-02
The final four candidate OSIRIS-REx sample sites
Map of Bennu showing the locations of the IAU-named surface features
Diagram of the orbits of Bennu and the inner planets around the Sun.
Animation of 101955 Bennu's position relative to the Earth, as both orbit the Sun, in the years 2128 to 2138. 2135 close approach is shown near the end of the animation. Earth · 101955 Bennu
The successful October 2020 sample collection, showing OSIRIS-REx touching down on the Nightingale sample site
Trajectory in the Solar System from 9 August 2016 to 24 September 2023
Trajectory around 101955 Bennu from 25 December 2018
References
- ↑ 1.0 1.1 1.2 "JPL Small-Body Database Browser: 101955 Bennu (1999 RQ36)" (2017-09-01 last observation. Solution includes non-gravitational parameters). Jet Propulsion Laboratory. Archived from the original on 19 March 2018. Retrieved 20 August 2016.
- ↑ 2.0 2.1 "(101955) Bennu = 1999 RQ36 Orbit". Minor Planet Center. Retrieved 2018-03-21.
- ↑ "(101955) Bennu". NEODyS. University of Pisa. Retrieved 1 December 2015.
- ↑ Barnouin, O. S. (March 19, 2019). "Shape of (101955) Bennu indicative of a rubble pile with internal stiffness". Nature Geoscience. 12 (4): 247–252. Bibcode:2019NatGe..12..247B. doi:10.1038/s41561-019-0330-x. PMC 6505705. PMID 31080497.
- ↑ "Planetary Habitability Calculators". Planetary Habitability Laboratory. University of Puerto Rico at Arecibo. Archived from the original on 5 September 2019. Retrieved 6 December 2015.
- ↑ 6.0 6.1 Lauretta, D. S. (March 19, 2019). "The unexpected surface of asteroid (101955) Bennu". Nature. 568 (7750): 55–60. Bibcode:2019Natur.568...55L. doi:10.1038/s41586-019-1033-6. PMC 6557581. PMID 30890786.
- ↑ Hergenrother, Carl W; Maria Antonietta Barucci; Barnouin, Olivier; Bierhaus, Beau; Binzel, Richard P; Bottke, William F; Chesley, Steve; Clark, Ben C; Clark, Beth E; Cloutis, Ed; Christian Drouet d'Aubigny; Delbo, Marco; Emery, Josh; Gaskell, Bob; Howell, Ellen; Keller, Lindsay; Kelley, Michael; Marshall, John; Michel, Patrick; Nolan, Michael; Rizk, Bashar; Scheeres, Dan; Takir, Driss; Vokrouhlický, David D; Beshore, Ed; Lauretta, Dante S (2018). "Unusual polarimetric properties of (101955) Bennu: similarities with F-class asteroids and cometary bodies". Monthly Notices of the Royal Astronomical Society: Letters. 481 (1): L49–L53. arXiv:1808.07812. Bibcode:2018MNRAS.481L..49C. doi:10.1093/mnrasl/sly156.