Announcements

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Announcements

• Go to Observatory on a Monday or Thursday night
  to observe Uranus if you didn't observe Jupiter
  during the first half of the semester. Or you
  can do both for extra credit. (Make sure your
  sheet gets stamped at the observatory!!!!!!)?

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Surface of the Moon
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Formation of Maria. First, a meteor
impacts the surface of the moon.
The crater is deep enough to make it all the way
through the crust and into the mantle.
Hot lava rushes in from the mantle and
floods the impact crater. The
lava cools to make a smooth, craterless surface.

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Example of paving in Maria
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Near Side vs Far Side
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Crust thickness
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Moon Formation theories
Sister Theory The Moon formed right alongside
Earth.   Problem Where's all the Moon's iron?
Composition lacking. Fission Theory Earth was
spinning so fast the Moon split off.   Problem
Why is the Moon's orbit inclined to Earth's
rotation? Capture Theory Earth's gravitational
field captured the Moon.   Problem Where did
the orbital energy go? Also, rocks are too
similar.
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Best theory so far The Giant Impact
Theory Something roughly the size of Mars hit us
in an oblong collision, spewing mostly mantle
into space around Earth.