Astronomy and Earth Science Basics

The galaxy containing our solar system.

• Andromeda

• Milky Way

• Triangulum

• Whirlpool

A natural object (satellite) that orbits a planet.

• Star

• Asteroid

• Moon

• Comet

An imaginary line that passes through Earth’s center from the North Pole to the South Pole.

• Equator

• Axis

• Diameter

• Meridian

The path that one object in space takes around another object in space.

• Orbit

• Rotation

• Revolution

• Trajectory

The motion of one object around another object.

• Rotation

• Revolution

• Translation

• Orbit

The process by which rocks are broken down.

• Erosion

• Weathering

• Sedimentation

• Metamorphism

An object made of rock, ice, dust, and gas that revolves around the Sun.

• Asteroid

• Planet

• Comet

• Meteor

A large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space.

• Galaxy

• Nebula

• Cluster

• Universe

The turning of an object on its axis.

• Revolution

• Translation

• Rotation

• Circumference

An object that is found in the solar system, orbits the Sun, and is much smaller than a planet.

• Asteroid

• Comet

• Planet

• Moon