The ratio between the measurements on a map or model and the actual proportions of an object

The total amount of matter in an object; not dependent upon gravitational pull

A measure of the force of gravity on an object

A unit of measure equal to the average distance between Earth and the sun, about 150 km

A bowl shaped pit on a planet, moon, or asteroid formed by the impact of an object

A small, mostly rocky solar system object that orbits independently around the Sun; minor planet

A large group of asteroids that orbits the Sun between Mars and Jupiter

A celestial body composed of a mixture of rocks, frozen gases, cosmic dust, water ice, and organic compounds that orbit the Sun in a variety of elliptical paths that pass close to the Sun and swing to the outer reaches of the solar system

The streak of light that is produced when a meteoroid burns as it enters an atmosphere

A solid object moving in interplanetary space, distinguished from asteroids, and planets by its smaller size

The time that it takes an object to orbit another object one complete time

The branch of science that studies the stars, planets, and other objects in space

A scientist who studies the stars, planets, and other objects in space

Having or representing the earth as the center, as in the former astronomical systems

The astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System

A large system of dust, gas stars, and other celestial bodies that has a particular shape

The entirety of everything that is known to exist in space

A concentration of dust and gas in space

A contracting mass of gas which represents an early stage in the formation of a star

An observed pattern of stars

A unit of astronomical distance equivalent to the distance that light travels in one year, which is nearly 6 trillion miles

Of or having to do with solid rock; name given to the four inner planets (Mercury, Venus, Earth, and Mars)