1. This is one of the more famous images of the Earth from the Apollo program, taken by the Apollo 8 astronauts as they became the first humans to circumnavigate the Moon.
Title: View of rising Earth about five degrees above the Lunar horizon Description: The rising Earth is about five degrees above the lunar horizon in this telephoto view taken from the Apollo 8 spacecraft near 110 degrees east longitude. The horizon, about 570 kilometers (250 statute miles) from the spacecraft, is near the eastern limb of the Moon as viewed from the Earth. On the earth, the sunset terminator crosses Africa. The south pole is in the white area near the left end of the terminator. North and South America are under the clouds. The lunar surface probably has less pronounced color than indicated by this print.

2. PHOTO CAPTION GALILEO December 22, 1992 P TOP GLL/EM2 3 Eight days after its encounter with the Earth, the Galileo spacecraft was able to look back and capture this remarkable view of the Moon in orbit about the Earth, taken from a distance of about 6.2 million kilometers (3.9 million miles), on December 16.
The picture was constructed from images taken through the violet, red, and 1.0-micron infrared filters. The Moon is in the foreground, moving from left to right. The brightly-colored Earth contrasts strongly with the Moon, which reflects only about one-third as much sunlight as Earth. Contrast and color have been computer-enhanced for both objects to improve visibility.
Antarctica is visible through clouds (bottom). The Moon's far side is seen; the shadowy indentation in the dawn terminator is the south-Pole/Aitken Basin, one of the largest and oldest lunar impact features, extensively studied from Galileo during the first Earth flyby in December The Galileo project, whose primary mission is the exploration of the Jupiter system in , is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.

4. Earth’s Moon Earth’s only natural satellite
We are the only planet with just one moon
When compared to the host planet – our moon is the largest proportionally
240,000 miles from Earth

5. Earth / Moon Comparison
Diameter – 7930 miles
23.5 degree tilt (seasons)
Surface Temperatures
-100°F to 120°F
Thick atmosphere
Liquid water at surface
Length of day – 24 hours
Diameter – 2160 miles (≈1/4 the diameter of the Earth)
7° tilt (no seasons)
Surface temps
-243°F to 224°F
No atmosphere (dry and airless)
Length of day – 27.3 Earth days

6. The Lunar Landscape The moon’s surface includes 3 major areas
Highlands (Lunar terrae - latin for moon “land”)
These are the bright areas of the moon
Heavily cratered
Lunar maria – ( moon seas)
Dark, smooth areas on the moon
Craters
Formed by impacts from outer space

7. Moon’s Surface
Regolith - layer of rock and rock dust covering the surface of the moon
Sometimes called “lunar soil” – has no organic material like Earth soil
3 to 15 meters deep
4 Layers
Lunar regolith is formed by the bombardment of meteoroids

8. Meteors, Meteoroids, Meteorites
Meteoroid – a chunk of rock or dust in space
Meteor – when a meteoroid comes in contact with Earth’s atmosphere and produces a streak of light
Meteorite – when a meteor hits the Earth’s surface

9. Impact craters on the Moon
Caused by meteoroids
Some as large as the state of Connecticut – others smaller than the head of a pin
This portion of the Moon is covered by numerous circular holes. These are impact craters, each of which was formed when an asteroid or comet collided with the Moon's surface. The large number of craters in this region indicates that this part of the Moon is quite ancient. Geologic processes have not erased the craters with time.

10. Types of Craters Simple Craters
Bowl shaped with rounded, or small flat floors
This image shows a simple crater on Mars that has no central peak or terraces around its edges. The crater is 2 kilometers (about 1 mile) wide. An extensive blanket of ejecta covers the area around the rim.
Image from the Mars Global Surveyor, courtesy of the Lunar and Planetary Institute.

11. Types of Craters Complex Large craters Usually have terraced walls
Have a central peak (or peaks) that rise up from a broad, flat floor
Copernicus is a large crater (93 kilometers or 60 miles wide) on the Moon. The inner walls of the crater have collapsed to form a series of step-like terraces, and a central peak is visible in the center of the image.
Apollo 17 image courtesy of NASA.

12. Types of Craters Impact Basins Largest type of impact crater
Usually over 250 miles wide
Impact basins are very large impact structures that are more than 300 kilometers (185 miles) in diameter. The largest impact basin on the Moon is 2500 kilometers (1550 miles) in diameter and more than 12 kilometers (7 miles) deep. Large impact basins are also found on other planets, including Mars and Mercury.
The large circular dark areas in the image are impact basins, created as huge impactors struck the Moon. Lava later flowed across the low floors of the basins, giving them a darker, smoother appearance than the surrounding, brighter highlands. The dark basins can be seen by the naked eye.

13. Parts of a crater Walls – like the sides of a bowl Floor – Rim –
Vary in steepness
May have giant steps called terraces
Floor –
May be flat or shaped like a bowl
Below ground unless filled in with lava
Rim –
Ring shaped pile of debris
Highest point along edge of crater
Ejecta –
The debris that shoots out or ejects from the impact site
Becomes thinner away from the crater

14. Parts of a crater
Rays
Bright streaks that start at the rim and extend outward for great distances

15. Large impacts cause the rock at the impact area to behave as a liquid
Central Peak
mountains that form at the center of a crater due to the impact
Only found craters larger than 40 km (25 miles) diameter

16. Barringer Crater - Arizona

17. Formation of the Moon

18. Theories on Moon Formation
Capture Hypothesis
Earth captured a fully formed moon in its gravitational pull
Problem
Highly unlikely – a close encounter would result in a collision or sending moon on different orbit around the sun

19. Theories on Moon Formation
Fission Hypothesis
Earth was spinning so fast a piece flew off forming the moon
Problem
No way to explain how Earth was spinning so fast and why we aren’t spinning that fast today

20. Theories on Moon Formation
Double-Planet Hypothesis
Earth and Moon formed together from the start
Problem
Cannot explain how the moons material got into orbit and stayed there (did not crash into Earth)
Cannot explain the moons rotation and motion around the Earth

21. Formation of the Moon
Collision- ring theory

22. Moon Formation Hypothesis
Collision-Ring Theory
A rogue planet the size of Mars collided with a very young Earth
Knocked material off into space which clumped together due to gravity and became our Moon

23. Collision Ring Theory Explains The way Earth Spins Earth’s Tilt
Why Earth has larger metallic core than the Moon
Same type / age of rocks found on Moon as on Earth

24. The Origin of the Moon
The theory that seems to best fit the evidence is called the collision- ring theory
About 4.5 billion years ago the solar system was full of rocky debris (some the size of small planets)
Scientists theorize a planet-sized object collided with the earth to form the moon