12/13/2011
First Telescopic Observations Dec 1609
The Moon
Lunar structure and features
Definitions:
• Mare / Maria
– Latin for sea(s) dark areas on surface of
Moon.
• Crater
– depression formed by meteor impact
• Rays / ejecta
– material displaced by crater formation
• Terminator
– Line of sunrise/sunset
Crater
Terminator
Craters
Lunar Statistics
Maria
•
•
•
•
•
Approximately 1/6 gravity of the Earth
Average distance 384,000 km
Diameter 3476 km
Same side always points to the Earth
Lunar temperature range 134 C to –170 C
Craters with
Rays and ejecta
• Exploration
– Over 100 missions to the Moon
– Apollo – 6 flights landed on Moon 1969-1972
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12/13/2011
Formation of The Moon & lunar
structure
Maria found on the side of the Moon closest to the Earth.
Earth Side
Far Side
• Formed from Giant impact
– Mars sized object struck Earth
– Similar rocks on Earth and Moon
• Lunar core more dense material
• Crust uneven thickness
• Most craters formed in the first
1,000,000,000 years (billion)
• Originally molten cooled from the outside.
• Early impact craters filled with molten lava
(Maria).
Images NASA
Crust
towards
earth
~60km
Crust on
the far
side
~100km
Maria found on the side of the Moon closest to the Earth.
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