The Moon

The Moon
Moon: Basic Facts
Diameter: 3500 km (2100 miles)
Average Distance: 380,000 km (240,000 miles)
Distance range: 360,000 – 400,000 km
Orbital eccentricity: .05
Orbital inclination: 5 degrees
Earth is 4x as large, 81x as massive
Bulk density: 3.3 gm/cc (3400 kg/m3)
Geology of the Moon
• Cratered Highlands
– Crater saturated
– Every point has been cratered
• Large late basins
– Late Heavy Bombardment
– Lunar Mountains are Basin Rims
• Dark plains (Maria)
– Lava flows
– Low crater density
• Recent bright craters
What it means
• Early accretion of Solar System
– Every accretion event is an impact
• Final stages of accretion swept up large bodies
• After the Late Heavy Bombardment, accretion
rate slowed dramatically
• Long afterward, lava filled some basins
• Little internal activity since maria flooding
• Rare large impacts
Basic Planetary Stuff
We Can Expect Basalt to be Very
Abundant in the Universe
Anorthosite: Lunar Highland Rock
With Some Very Simple Science, We Can
Understand the Geology of the Moon
Earth and Moon Histories
Lunar Rilles
How Lunar Rilles May Form
A “Lunar” Landscape?
Real Lunar Mountains
How We Got It So Wrong