101955 Bennu
Asteroid· orbits the Sun
Bennu is a small, dark, carbon-rich near-Earth asteroid — a loosely bound rubble pile sampled by NASA's OSIRIS-REx in 2020, whose material was returned to Earth in 2023.
Open in 3D viewSee 101955 Bennu in the live, interactive 3D map
Key facts
Radius
0.245 km
Distance from Sun
1.13 AU
Orbital period
436.4 days
Eccentricity
0.2037
Rotation
4.30 hours
Science
Physical
- Mean radius
- 0.245 km
- Mass
- 7.33 × 10¹⁰ kg · 0.000000000000998 Moon masses
- Density
- 1,189 kg/m³ · 1.2× water
- Rotation period
- 4.30 hours
Orbital
- Semi-major axis
- 1.13 AU
- Eccentricity
- 0.2037
- Inclination
- 6.03 °
- Orbital period
- 436.4 days
- Perihelion
- 0.897 AU
- Aphelion
- 1.36 AU
- Mean orbital velocity
- 28.1 km/s
Discovery
- Discovered
- September 11, 1999
- Discoverer
- the LINEAR survey
Composition
- Make-up
- A B-type rubble pile of hydrated clay minerals, carbonates and organic molecules — primitive material from the early Solar System.
Radiation & temperature
- Insolation
- 0.789 S⊕ · 79% of the sunlight Earth receives
- Geometric albedo
- 0.04
- Equilibrium temperature
- 259 K (-14 °C)
Discovery & history
- Discovered
- September 11, 1999
- By
- the LINEAR survey
- Method
- Photographic plates
- Name
- The ancient Egyptian Bennu bird (linked to creation and rebirth) — chosen by a nine-year-old in a naming contest.
Bennu is a small, dark, carbon-rich near-Earth asteroid found in 1999. As a potentially hazardous object and a pristine relic of the early Solar System, it was chosen as the target of OSIRIS-REx, which collected a sample in 2020 and delivered it to Earth in 2023.
- 2018OSIRIS-RExSample return
Orbited Bennu and snatched a sample in 2020, delivered to Earth in 2023.
Images
Images from open archives · credit shown per image