Chelyabinsk Meteoroid

Dimorphos is the small moonlet of asteroid Didymos and the target struck by NASA’s DART spacecraft. DART shortened its orbit by roughly 33 minutes, making Dimorphos the first celestial body whose motion humans deliberately changed.

Object class

Rubble-pile asteroid

Mass

~4 million metric tons

Estimated age

~4.5 billion years

Host

Didymos system

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.

Object class

S-type near-Earth asteroid

Mass

~35 billion metric tons

Estimated age

~4.5 billion years

Composition

Silicate rock (rubble pile)

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.

Object class

Carbonaceous near-Earth asteroid

Mass

~73 million metric tons

Estimated age

~4.5 billion years

Composition

Carbon-rich rock and boulders