Day and Night
The Seasons
The Moon
Moon Phases
100

This motion of the Earth causes day and night. 

What is Rotation?

100

This motion defines one year on Earth

What is the Revolution of the Earth?

100

This feature creates dark spots on the moon.

what are maria?

100

These events are caused by changing patterns of light and shadow. 

What are the phases of the Moon? 
200

The length of time it takes for the Earth to complete a full rotation on its axis.

what is 24 hrs (1 day)?

200

This characteristic of the Earth causes the four seasons. 

What is Earth's tilted axis?

200
This phenomenon takes 27 days to complete. 

What is the revolution (or rotation) of the Moon? 

200

This phase occurs when the moon is between the Earth and Sun in approx. alignment. 

What is a new moon? 

300

The apparent path of the Sun across the sky. 

What is the ecliptic? 

300

Every four years, this special day is added to the calendar. 

Leap Year, February 29

300

This phenomenon occurs when you combine the tilted orbital path of the Moon and its elliptical orbit. 

What is libration? 

300

This phase occurs when the moon is at a right angle to the Earth and Sun. 

What is a first quarter or third quarter moon? 

400

This time of day occurs in Sydney, Australia, when it is daytime in Odessa, Texas. 

What is night? 

400

This season occurs in the Southern Hemisphere when it is summer in the Northern Hemisphere. 

What is winter? 

400

This phenomenon is caused by the gravitational pull of the Earth.

What are tides? 

400

Length of a sidereal period. 

What is 27 days? 

500

the motion during the daytime that makes it seem like the Sun and stars are revolving around the Earth.

What is diurnal motion? 

500

An angle of 23.5 degrees.

What is Earth's tilt? 

500

A natural phenomenon in which the moon's revolution and rotation on its axis are locked together, so that a revolution and rotation both take 27 days.

What is synchronous rotation?

500

Length of a synodic period.

What is 29.5 days?