Cycles in our Solar System

Day and night are caused by

• Earth's tilt
• Earth's revolution around the sun
• eclipses
• Earth's rotation on its axis

Earth's rotation takes about

• 365 days
• 6 months
• 24 hours
• 1 month

One complete revolution of Earth around the sun takes about

• one rotation
• one season
• one year
• one eclipse

Earth has seasons because

• Earth rotates on its axis.
• The distance between Earth and the sun changes.
• Earth's axis is tilted as it moves around the sun.
• The temperature of the sun changes

When the north end of Earth's axis is tilted toward the sun, North America will experience

• This doesn't happen, so North America will experience nothing
• more direct rays and shorter days
• more indirect rays and longer days
• more direct rays and longer days

What marks the beginning of winter on December 21?

• solstice
• equinox
• both

What marks the beginning of a different season?

• Solstice
• Equinox
• Both

What can be the same size as small planets?

• comets
• asteroids
• hemispheres
• moons

In our solar system, there are ____ planets.

• 8
• 4
• 9
• 7

In which direction does the Earth move around the sun?

• clockwise

• counter clockwise

• It doesn't move around the sun.