101955 Bennu Facts for Kids

101955 Bennu (provisional designation 1999 RQ₃₆) is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999.

Bennu has a 1 in 2,700 chance of hitting Earth between the year 2178 and 2290, with the greatest risk being on 24 September 2182.

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 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.

Bennu is the target of the OSIRIS-REx mission which is intended to return samples to Earth in 2023 for further study. In October 2020, OSIRIS-REx briefly landed on Bennu, collected a sample of the surface, and departed Bennu in May 2021. A capsule containing the samples landed on Earth in September 2023.

Possible Earth impact

On average, an asteroid with a diameter of 500 m (1,600 ft; 0.31 mi) can be expected to impact Earth about every 130,000 years or so. A 2010 study by Andrea Milani and collaborators predicted a series of eight potential Earth impacts by Bennu between 2169 and 2199. The authors recognized that an accurate assessment of 101955 Bennu's probability of Earth impact would require a detailed shape model and additional observations.

The publication of the shape model and of astrometry based on radar observations obtained in 1999, 2005, and 2011 made it possible to publish a revised assessment of the impact probability. If an impact were to occur, the expected kinetic energy associated with the collision would be 1,200 megatons in TNT equivalent (for comparison, TNT equivalent of Tsar Bomba, the most powerful nuclear weapon ever tested, was approximately 54 megatons).

Images for kids

Series of Goldstone radar images showing Bennu's rotation.
Animation of Bennu rotating, imaged by OSIRIS-REx in December 2018.
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
OSIRIS-REx's first images of Bennu.
Animation of OSIRIS-REx's trajectory from 9 September 2016 to 24 October 2023. OSIRIS-REx; 101955 Bennu; Earth; Sun;
Animation of OSIRIS-REx's trajectory around 101955 Bennu from 25 December 2018 OSIRIS-REx · 101955 Bennu
Animation of OSIRIS-REx - touch down on Bennu
A compilation of radar images of asteroid Bennu (left) and a corresponding 3D shape model. (right)
Wide angle shot of the Northern Hemisphere of Bennu, imaged by OSIRIS-REx at an altitude of approximately 1.8 km (1.1 mi)
Bennu's regolith-covered surface as imaged by OSIRIS-REx
The Nightingale sample site imaged by OSIRIS-REx at touchdown. The circular TAGSAM head in the center of the frame is 1 ft (0.30 m) in diameter.

101955 Bennu facts for kids

Possible Earth impact

Images for kids

See also