Key Words

Terms preceded by an asterisk (*) are discussed in the Boxes.

asteroid

Kuiper belt

asteroid belt

liquid metallic hydrogen

average density

magnetometer

chemical composition

meteoroid

comet

minor planet

dynamo

Oort comet cloud (Oort cloud)

*escape speed

plate tectonics

ices

spectroscopy

impact crater

terrestrial planet

Jovian planet

trans-Neptunian object

*kinetic energy