Solar System Vocab

The path that an object such as a planet makes as it revolves around a second object

orbit

The movement of any object in orbit, such as the Earth moving around the sun, which takes 365 ¼ days to complete

revolution

The motion of a planet as it turns on its axis. This takes 24 hours to complete.

rotation

An imaginary line which runs through both poles of a planet

axis

An object that moves around another object in space

satellite

The different shapes the moon seems to have as it orbits around the Earth

phases

A huge burning sphere of gases

star

A group of objects in space that move around a central star

solar system

A large object that moves around a star

planet

Greek astronomer who believed in the Earth centered model. GEOCENTRIC

Aristotle

Egyptian astronomer who believed in the Earth centered model GEOCENTIC

Ptolemy

Polish astronomer who challenged the Geocentric model. He introduced the sun-centered model~ HELIOCENTRIC

COPERNICUS

Italian astronomer who believed Copernicus’ sun-centered model was correct because of improvements he made to his telescope *He was also put in jail because of his belief.

Galileo