Astronomy

Earth’s Moon

BellworkBellwork• In 1998, the Lunar Prospect mission

showed that there could be water on our moon. The craters near the poles may contain as much as 300 million metric tons of ice. The ice can only exist in the shadowed regions because the daytime temps can reach 134 degrees Celsius. In your notebook write at least one paragraph describing a how we could capture some of the ice and bring it back to Earth.

Moon Facts

• Revolves around the earth

• 1 rotation around earth is 27.3 days

• 1 rotation on its axis is also 27.3 days

This is the reason why we only see 1 side of the moon.

• Shines by reflecting sunlight from its surface

Phases and Rotation of the Moon

What are Moon Phases?

• Changing appearances of the moon as seen from earth.

• Phase depends on relative positions of the moon, earth and sun.

• Moon phases cycle takes 29.5 days

PhasesPhasesTermsTerms

Waxing- Phase when sunlit face is getting Waxing- Phase when sunlit face is getting bigger bigger

Waning- Phase when sunlit face is getting Waning- Phase when sunlit face is getting smaller smaller

Gibbous- Phase when more the half of it face Gibbous- Phase when more the half of it face is showing. is showing.

Crescent- Phase when a ¼ of it’s face is Crescent- Phase when a ¼ of it’s face is showing showing

Full- Phase when all of moons face is litFull- Phase when all of moons face is lit

Phases of the moon

New Moon• Not seen

Why is a new moon not seen?The reason we don't see any light on the moon during a new moon is because the far side of the moon is getting all the light, while the side we see is cast completely in shadow. When we have a full moon it's because the moon is facing us AND the sun, so we see its light reflected fully. The other phases are the stages in between.

Waxing Crescent

• After new moon, more and more

of moon is visible. Banana

shaped

1st Quarter• Half is seen

Waxing Gibbous• ¾ is seen

Full Moon All is seen

Waning Gibbous• ¾ is seen

• After the full moon,

less is visible

last Quarter• Left Half is seen

Waning Crescent• Banana

shaped

Waxing Crescent

First Quarter

Full Moon

Waxing Gibbous

Last Quarter

Waning Gibbous Waning Crescent

New Moon

1

2

8.

1.

2.

3.

4.

5.

6.

7.

EclipsesHow do eclipses occur?

• Revolution of the moon causes them

• Occur when earth or moon temporarily block the sunlight from reaching the other

Eclipses can occur only when the sun, moon and earth are perfectly lined up.

When can eclipses occur?

Moon

moves

Between

Sun and

earth

What is a Solar Eclipse?

Effects of Motion

Solar Eclipse

– When the Moon passes between the Sun and Earth causing the Moon’s shadow to fall on the Earth.

What is a

Lunar

Eclipse?

Earth moves between the moon and the sun

Lunar Eclipse

– When the Earth passes between the Sun and Moon causing the Earth’s shadow to fall on the Moon.

Lunar Eclipse on March 3, 2007

Igneous rocks of the maria are

thought to be 3-4 billion years old (youngest rocks found on moon

surface).

Theories about the moon‘s origin

1. Captured by earths vicinity

2. Condensed from loose material surrounding earth during early formation of the solar system

3. Blob of molten material was ejected from earth while earth was still in its early molten stage

Apollo missions led many scientists to support the

impact theory

- Moon was formed 4.6 billion years ago when a Mars-sized

object collided with earth. Gas and debris was thrown into orbit then condensed into a

single mass, forming the moon.

Origins of the Moon

Surface of the Moon

The Formation of the MoonSection 4

Copyright © by Holt, Rinehart and Winston. All rights reserved.