Cosmic Scale
Bennu
Near-Earth asteroid · Orbits the Sun near Earth
How big is Bennu?
Bennu is about 490 m across.
See Bennu in 3D, at true scale
Bennu is a rubble-pile asteroid about half a kilometre wide: loose rocks and boulders held together by their own feeble gravity. NASA's OSIRIS-REx mapped it for two years, grabbed a sample from its surface in 2020 and returned it to Earth in 2023.
At a glance
| Diameter | 490 m |
|---|---|
| Mass | 7.33 × 10¹⁰ kg |
| Diameter compared with Earth | 0.000 × Earth |
| Size | About 490 m across |
| Day | 4.3 hours |
| Sample returned | 121.6 g, in 2023 |
| Shape | Like a spinning top |
Good to know
- When the spacecraft touched it, the surface gave way like a ball pit; it would have sunk in had it not fired its thrusters.
- Its sample contains the building blocks of life, including all five bases found in DNA and RNA.
- It has a small chance of hitting Earth in the late 2100s, about 1 in 2,700.
- Next larger: Comet 67P · 4.0 km