1. Earth’s Moon
Chapter 1, Section 4, p30-33

2. Earth’s Moon
Telescope: device built to observe distant objects by making them appear closer
Galileo created his own telescope
2 lenses placed in wooden tube
Lenses focused light
Galileo pointed his telescope at the moon
Saw surface in more detail than anyone before him
Irregular surface with remarkable features
Previously believed to be smooth

3. Earth’s Moon
Links on Earth’s moon:
(scn-0614)

4. The Moon’s Surface
Features on the moon’s surface include maria, craters, and highlands
Maria
Maria: dark, flat areas
Latin for “seas”
Galileo believed maria were oceans
Hardened rock from ancient lava flows 3-4 b.y.a.
Highlands
Galileo inferred light colored features were highlands / mountains
Galileo could see shadows cast by rugged highlands

5. The Moon’s Surface
Features on the moon’s surface include maria, craters, and highlands
Craters
Craters: large, round pits
Scientists once thought craters formed by volcanoes
Created by meteoroid impacts
Meteoroids: chunks of rock or dust from space
Maria has fewer craters than surrounding areas
Most impacts formed early in moon’s history before maria formed
Earth has fewer craters than moon
Worn away over time by wind, water, and other forces
Moon’s surface has changed little
Lacks wind, water, and other forces

6. Characteristics of the Moon
Earth’s closest neighbor – very different characteristics
The moon is dry and airless
Compared to Earth, the moon is small and has large variations in its surface temperature
wear bulky space suit to breathe, protect against sunburns, and keep temperature comfortable

7. Characteristics of the Moon
Size and Density
¼ Earth’s diameter
1/80 Earth’s mass
Moon’s density similar to Earth’s outer layers
Earth has very dense core

8. Characteristics of the Moon
Temperature & Atmosphere
Range: 130°C to -180°C
Extreme temperatures caused by no atmosphere
Weak surface gravity allows atmospheric gases to escape into space

9. Characteristics of the Moon
Water
No liquid water
Evidence of large patch of ice near moon’s poles
Areas shielded by crater walls
Valuable for future colonies as transporting water would be expensive

10. The Origin of the Moon Where did the moon come from? Rejected ideas:
Was it formed elsewhere and captured by Earth’s gravity
Was it formed near Earth at the same time Earth formed?

11. The Origin of the Moon Where did the moon come from?
Collision-ring theory
Scientists theorize that a planet-sized object collided with Earth to form the moon
Material from this object and Earth’s outer layer was ejected into orbit
Ejected material formed a ring
Gravity caused material to combine to form moon

12. Homework
Read Chapter 1, Section 4; p30-33
Answer ?s 1-3 p33