1. A look at our nearest neighbor in Space!
The Moon
A look at our nearest neighbor in Space!

2. What is the Moon? A natural satellite
One of more than 96 moons in our Solar System
The only moon of the planet Earth

3. Location, location, location!
About 384,000 km (240,000 miles) from Earth
3,468 km (2,155 miles) in diameter (about ¼ the size of Earth)

4. Birth of the Moon First Stage Moon was once part of the Earth.
A large body collided with Earth creating debris
Earth’s gravity eventually caused the Moon to form

5. Second Stage
Initially a sphere of molten rock
Eventually, this mix of rock separated.
Third Stage
The outer surface cooled, forming a crust.
Craters started to form from impact with meteoroids.
Meteoroids decreased
Moon cooled completely
Moon changed little in 3 billion years

6. Cut to the Core Crust - about 70 km thick Mantle
Core - radius is km

7. The Moon’s Surface No atmosphere No liquid water Extreme temperatures
Daytime = 130C (265°F)
Nighttime = -190C (-310 F)
1/6 Earth’s gravity

8. The Moon’s Surface
Lunar rocks and dust covering the surface is called the regolith
1 – 6 meters deep
The lack of an atmosphere let many more meteorites strike the moon’s surface, creating this layer of crushed rock.
Anorthosites = light-colored, coarse-grained rocks in the lunar highlands.
Breccia = contains fragments of other rocks that have melted together

9. Lunar Features - Highlands
Mountains up to 7500 m (25,000 ft) tall
Rilles (trenchlike valleys)

10. Lunar Features - Craters
Bowl shaped depressions
Up to 2500 km (1,553 miles) across
Most formed by meteorite impact on the Moon
Some formed by volcanic action inside the Moon

11. Lunar Features - Craters
Marks left from displaced debris after impacts are called rays

12. Lunar Features - Maria
Originally thought to be “seas” by early astronomers
Darkest parts of lunar landscape
Filled by lava after crash of huge meteorites on lunar surface 3-4 billion years ago
Mostly basalt rock

13. Craters
Maria

14. Movements of the Moon Orbit is an ellipse, not circular
Apogee (farthest from Earth)
Perigee (closest to Earth)
Revolution – Moon orbits the Earth every 27 1/3 days
The moon rises in the east and sets in the west
The moon rises and sets 50 minutes later each day
Rotation – Moon turns on its axis every 27 days
Same side of Moon always faces Earth

15. Often Referred to the….
Dark Side of the Moon

16. Far Side of the Moon First seen by Luna 3 Russian space probe in 1959
Surface features different from near side
More craters
Very few maria
Thicker crust

17. It’s Just a Phase Moonlight is reflected sunlight
Half the moon’s surface is always reflecting light
From Earth we see different amounts of the Moon’s lit surface
The amount seen is called a “phase”

18. Waxing and Waning New moon Waxing Crescent moon First Quarter moon
Waxing Gibbous moon
Full moon
Waning Gibbous moon
Third Quarter moon
Waning Crescent moon

19. FOUR MAIN SHAPES
FULL
Four Basic Shapes
CRESCENT
GIBBOUS
QUARTER

21. Moon Phases
New Moon – the moon is between the sun and the earth, and we see the unlighted side. No lighter area of the moon is visible from Earth.
As the sun continues to move, part of the moon becomes visible. When the size of the visible portion is increasing, and we first see a sliver of the moon, it is called the waxing-crescent phase

22. When the moon has moved through one quarter of its revolution, the moon looks like a semicircle, called a first-quarter phase.
The lighted portion of the moon continues to increase, making it larger than a semicircle which is called the waxing-gibbous phase.

23. Halfway through its orbit, the Earth is in between the Sun and the Moon, creating a full moon phase. The entire half of the moon is reflecting light off the sun at this phase
The moon continues, now decreasing in the amount of lighten surface. When the moon is not full anymore, but decreasing back to a semicircle, it is called a waning-gibbous phase.
Eventually, the moon reaches a semi-circle again, called the last-quarter phase.
The moon continues, now decreasing in the amount of lighten surface. When the moon is not full anymore, but decreasing back to a semicircle, it is called a waning-gibbous phase.
Eventually, the moon reaches a semi-circle again, called the last-quarter phase.
The moon continues, now decreasing in the amount of lighten surface. When the moon is not full anymore, but decreasing back to a semicircle, it is called a waning-gibbous phase.
The moon continues, now decreasing in the amount of lighten surface. When the moon is not full anymore, but decreasing back to a semicircle, it is called a waning-gibbous phase.
The moon continues, now decreasing in the amount of lighten surface. When the moon is not full anymore, but decreasing back to a semicircle, it is called a waning-gibbous phase.
The moon continues, now decreasing in the amount of lighten surface. When the moon is not full anymore, but decreasing back to a semicircle, it is called a waning-gibbous phase.

24. Eventually, the moon reaches a semi-circle again, called the last-quarter phase.
The light continues to decrease, when finally only a sliver of the moon is visible, which is called the waning-crescent phase.

25. The moon is now back where it started, and the process repeats
The moon is now back where it started, and the process repeats. The whole process takes 29.5 days (an extra 2 days is needed from the 27.3 days for the moon to get back to its original position) This means that you usually have one of each phase per month. Sometimes, two full moons happen in one month. The second full moon of a
month is usually called a
blue moon.

26. Earth
Plane of earth’s orbit
Moon
Plane of lunar orbit
Moon

27. Lunar Eclipses Moon moves into Earth’s shadow, darkens the Moon
Umbra: center, all sunlight is blocked
Penumbra: outer part of shadow sunlight partially blocked.
About 2-3 per year
Last up to 4 hours

28. Solar Eclipses Moon moves between Earth and Sun
Moon casts a shadow on part of the Earth
Total eclipses rare – only once every 360 years from one location!

29. The Tides Tides caused by pull of Moon’s gravity on Earth High tide –
Side facing Moon and side away from Moon
Every 12 hours, 25 ½ minutes
Low tide –
On sides of Earth