If all the asteroids in the asteroid belt had coalesced to form a planet, what size would it have been?

Asked by: Adam King, Huddersfield

Surprisingly, the total mass of material in the asteroid belt is only about 4 per cent of the mass of the Moon. About half of this mass is contained in the four largest asteroids: Ceres, Vesta, Pallas and Hygiea. If all this material were concentrated into a single object with the same density as Ceres, it would be a dwarf planet about 700km in radius (Pluto, another dwarf planet, has a radius of 1,188km).

Such a small object would have little impact on the Solar System as a whole.

Read more:

• Could we stop an asteroid from hitting Earth?
• Could an asteroid impact push the Moon closer to us?

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