\if we could put all the asteroids together, their total mass would be if we could put all the asteroids together, their total mass would be greater than the mass of earth but less than the mass of jupiter much less than the mass of any terrestrial planet about the mass of mercury about the mass of earth

much less than the mass of any terrestrial planet

Explanation:

According to www.wikipidia.com

The mass of all the objects of the asteroid belt, lying between the orbits of Mars and Jupiter, is estimated to be about 2.8–3.2×1021 kg, or about 4% of the mass of the Moon. Of this, Ceres comprises 0.95×1021 kg, a third of the total.

While mass of terrestrial planet is

5.97 x 1024 kg (which works out to 5,970,000,000,000 trillion metric tons) Earth is the most massive of all the terrestrial planets (www.universetoday.com)

By doing the calculation, mass of all the asteroid are much less than the mass of any terrestrial planet