Solar System

In its orbit, Earth circles the sun once every year. This movement around the sun is called a(n)

• rotation

• revolution

Rocks and pebbles that hit Earth's atmosphere and burn up are called

• meteors

• comets

• satellites

• keppers

The spinning of Earth on its axis is an example of its

• newton

• gravity

Kepler's Laws of Motion explain why

• planets closer to the sun travel faster in their orbits than planets that are far away from the sun

• comets have long tails

Earth rotates on an imaginary line that runs from the North Pole to the South Pole. This line is called Earth's

• equator

• axis

The distance from Earth to the sun is 150 million kilometers (93 million miles). We call this distance

• one astronomical unit

• escape velocity

An object that orbits a planet is called a(n)

• luna

• asteroid

Tides on Earth are controlled by

• friction

• the gravity of the moon