Asteroids and comets: how big are they?

Asteroids and comets range from boulders to worlds hundreds of kilometres wide. These are some of the best studied, visited by spacecraft or seen for centuries.

See asteroids & comets in 3D, at true scale

#	Name	Diameter	× Earth
1	Bennu Near-Earth asteroid	490 m	0.000
2	Comet 67P Churyumov–Gerasimenko	4.0 km	0.000
3	Halley's Comet Periodic comet	11.0 km	0.001
4	Vesta Protoplanet in the asteroid belt	525 km	0.041

Asteroids & comets

Vesta

Vesta is the second-largest body in the asteroid belt and the brightest asteroid in our sky.

Halley's Comet

Halley's Comet is the most famous comet of all: the first known to return on a schedule, and the only bright one that does so within a human lifetime.

Comet 67P

67P/Churyumov–Gerasimenko is a comet shaped like a rubber duck, two lumps joined by a neck.

Bennu

Bennu is a rubble-pile asteroid about half a kilometre wide: loose rocks and boulders held together by their own feeble gravity.