Exploring Space

Large bodies that orbit the Sun

• comet

• asteroid

• planets

• meteor

an enormous system of gases, dust, and stars held together by gravity.

• star

• galaxy

• comet

• planets

The four planets farthest from the Sun.

• Outer planets

• Inner planets

• galaxy

• planets

brightness of a star as perceived from Earth

• light year

• ellipse

• coma

• magnitude

giant sphere of glowing gas

• star

• light-year

• comet

• solar system

first stage in the formation

• star

• protostar

• outer planet

• comet

The sun and all the bodies that revolve around it

• star

• light-year

• Solar System

• comet

Chunk of matter that enters the Earth's atmosphere and is heated by friction with air; often called a "shooting star"

• protostar

• comet

• magnitude

• meteor

Unit of measurement for distance outside the solar system and equal to about 9.5 trillion km

• star

• moon time

• asteroid

• light-year

Chunk of meteor that falls to the ground

• meteor

• meteorite

• comet

• galaxy