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.
