If Our Estimates of the Number of Comets in Every

Multiple Choice

If our estimates of the number of comets in every part of the solar system are correct, the total mass contained in comets must be:

A) about the mass of Ceres, the largest asteroid
B) about the mass of the Earth
C) about the mass of the Moon
D) on the order of the mass of all the planets put together
E) since comets are mostly vapor, their total mass is less than that of the moons of Mars