Earth, Moon, Sun

Front 1

gravity

Back 1

a force that pulls to keep objects on the ground

Front 2

waxing

Back 2

getting bigger

Front 3

inertia

Back 3

energy of forward motion

Front 4

orbit

Back 4

something moving in a circular motion that is created from a balance of gravity and inertia

Front 5

waning

Back 5

getting smaller

Front 6

rotation

Back 6

to spin on an axis

Front 7

revolution

Back 7

to move in an orbit around another body

Front 8

Moon Formation Theories (3)

Back 8

1. The moon was a separate body and captured by Earth's gravity.
2. The moon formed at the same time as Earth.
3. The Earth was spinning so fast that a piece blew off.

Front 9

*Impact Explanation

Back 9

While Earth was forming a Mars sized object collided with Earth and blasted a piece of Earth's mantle into space.

Front 10

Ejection Explanation

Back 10

The debris (mantle material from Earth) began to revolve around Earth.

Front 11

Formation Explanation

Back 11

The debris began to clump together to form the moon. Later the moon cooled and impacts created deep basins and fractured the surface. This made the moon we see today.

Front 12

Features of the Moon

Back 12

many craters
same material as Earth's mantle
no atmosphere
frozen water
no life
1/6 of Earth's gravity
rotates and revolves
4.6 billion years old

Front 13

axis

Back 13

an imaginary line on which a body rotates

Front 14

crescent

Back 14

a phase of the moon between a new moon and quarter phase

Front 15

gibbous

Back 15

a phase of the moon between a full moon and quarter phase