101955 Bennu size and scale context

Bennu is a carbon-rich near-Earth asteroid explored by NASA’s OSIRIS-REx mission. Returned samples contain carbon-rich material, water-related minerals, and unexpected phosphates, hinting that Bennu’s parent body may once have been part of a small primitive ocean world. Read its scale context, comparisons, and journey links on the canonical object page.

DimorphosRubble-pile asteroid·177 m

25143 ItokawaS-type near-Earth asteroid·535 m

101955 BennuCarbonaceous near-Earth asteroid·565 m

65803 DidymosBinary near-Earth asteroid·851 m

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Asteroids

25143 Itokawa

25143 Itokawa is the small near-Earth asteroid that Japan's Hayabusa spacecraft landed on in 2005, scooping up grains and returning them to Earth in 2010 – the first sample ever brought back from an asteroid. Hayabusa revealed it to be a rubble pile, a loose heap of fragments held together by gravity rather than a single solid rock.

Scale fact535 mmaximum extent

Object class: S-type near-Earth asteroid
Mass: ~35 billion tonnes
Estimated age: ~4.5 billion years
Composition: Silicate rock (rubble pile)

Asteroids

101955 Bennu

Scale fact565 mmaximum extent

Object class: Carbonaceous near-Earth asteroid
Mass: ~73 million tonnes
Estimated age: ~4.5 billion years
Composition: Carbon-rich rock and boulders

Asteroids

65803 Didymos

Didymos is the larger member of a binary near-Earth asteroid system and the anchor of NASA’s DART planetary-defense test. In 2022 the spacecraft struck its small moon Dimorphos to change its orbit.

Scale fact851 mmaximum extent

Object class: Binary near-Earth asteroid
Composition: Silicate (stony) rock
Mass: ~520 million tonnes