RAP1. _____force that keeps the planets from

being pulled into the sun (gravity)

2. _____ contains galaxies, gas, energy, comets, space rocks (big bang theory)

3. _____ theory that says a large dense massive ball of gases exploded and the universe began (big Bang theory)

4.____person who came up with the heliocentric model (astronomers)e(as

5. _____ the motion of one object moving around another object (rotation/revolution)

Key Questions

1. What causes the phases of the moon?

2. What is waxing?

3. What is waning

4. What are the phases of the moon?

1. The moon has phases because it revolves around the Earth and the sunlight hits the moon at different angles .

• 2. Waxing-getting larger• increasing light on the right

`

• 3. Waning-light is getting smaller• no light on the right

18.2 Phases of the Moon• The lighted side of the Moon faces away

from Earth.• How the moon appears to Earth dwellers at

different positions in its orbit is shown below:

New Moon

•part of the moon facing Earth is dark•sunlight shines on the back side of the moon.•moon is between the Earth and the Sun.•Solar Eclipse•Spring tide

Phases

Waxing Crescent

• A small part of the right side of the moon is lit.

• The light grows every day.

Phases

First Quarter

• The right half of the moon is lit• Neap tide • The light is still growing.

Phases

Waxing Gibbous

• More than half of the right side of the moon is lighted.

• The light is still growing.

Phases

Full Moon

• Moon is completely lit• Earth is between the sun and the moon• lunar eclipse• Spring tide

Phases

Waning Gibbous

• A small part of the right side of the moon is dark.

• The light is growing smaller.

Phases

Last Quarter or Third Quarter

• The right half of the moon is dark• Neap tide• The light is getting smaller.

Phases

Waning Crescent

• More than half of the right side of the moon is dark.

• The light is getting smaller and smaller until it is a new moon.

Phases