Solar System, Ch. 21

The closer a planet is to the sun, the _______________ it moves.

Inner planets include

The sun's _____________ keeps the planets in orbit.

Earth's seasons are the result of earth's

An AU is approximately

The invention of the telescope in the _____________ led to the discovery of more planets.

The outer planets are mostly made of 

The outer planets are 

Millions of small, rocky objects that orbit the sun in a belt between Mars and Jupiter.

Synonym for earth's movement around the sun.

Planets, dwarf planets, asteroids, and comets __________ light from the sun.

Synonym for earth moving around its axis.

Revolution time is 

There are officially ____ planets in our solar system.

___: spherical object that orbits the sun, does not have more mass than other objects around it

The sun is 

The eighth planet in our solar system is

Rotation time is

The inner planets are made of

AU stands for

The ancient Greeks called objects in the sky "planets," which means 

The "gas giants" refer to 

The fifth planet in our solar system is

The second planet in our solar system is

The largest object in the solar system is the