formation of the moon what properties were known about the moon prior to apollo? orbital period mass...

Anatomy of the Moon

Highlands.

• Rough terrain • many craters. • 3.9 to 4.4 by • Anorthosite• Breccia

Maria (Seas)

– flat – roughly circular – not many craters – rocks are like basalt – 3.1 to 3.8 by.

• Regolith– Lunar soil– Physically Weathered rock

Craters

• Craters– Meteor impacts– Methods to determine age

• Superposition• Amount of weathering

Phases of the Moon

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Near Side

Far Side

Lunar Landing

Locations

Model for the Formation of the Solar System

Models for the Formation of the Moon

• Fission Theory– Earth had a baby– Poor model

• Why did it come out• Where did is come out

Models for the Formation of the Moon

• Capture Theory– Asteroid was passing by the Earth and got caught in

its gravitational pull. – Is the accepted model for the formation of small

moons of Mars and big planets

Models for the Formation of the Moon

• Co-Accretion, Condensation or Colliding Planetesimals Theory– Earth had a sister– Planet and moon formed at the same time, same way

• Large moons on large planets are believed to have formed this way

Models for the Formation of the Moon

• Collision-Ejection or Ejected Ring Theory– Impact from a large object tour off a large piece

of the Earth which was ejected into orbit around the Earth. This material reformed into the moon.

What properties were known about the moon since Apollo?

• 4.5 BY• Highlands are made of Anorthosite• Maria are made of Basalt• Rock has very little volatile material

– No Water– The ice found recently at the

lunar north pole is from comets – found in the cold shaded craters.

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Short History of the Moon• Formed 4.6 billion years ago (bya) at about the

same time as the Earth with continuous and intense meteor bombardment.

• By 4.2 bya the solid solidified, bombardment continued.

• By 3.8 to 3.1 bya the seas are formed by massive lava flows

• 3.o bys to present, the moon is geologically dead