Moon Info

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Moon Info

• Created by a real bum

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Synchronous Orbit/Rotation

• The time it takes the moon to rotate once is
  equal to the time it takes to orbit around the
  Earth once. 27.3 days
• The same side of the moon is ALWAYS facing the
  earth (called nearside).
• We cannot see the Farside from Earth. The 1st
  time humans saw Farside was 1959 (Soviet
  Interplanetary Satellite).

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Farside!!!

• Image from Apollo 16. Left side is part of
  nearside.
• Greater amounts of Craters and virtually no Maria
  (dark portions easily visible on Nearside)!!!

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Earthshine

• dark side of the moon is illuminated by the
  Earths reflected light.

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Formation Theories

• Simultaneous formation- moon and Earth formed
  together at the same time from the solar nebula.
• Capture Theory- Earths gravity captured a large
  planetessimal early in the formation of the SS.
• Collision Theory- Mars sized planetessimal
  collided with Earth. Ejected material coalesced
  to form the moon.

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Lunar Features

• Oceanus (Ocean)
• Maria (Seas)
• Sinus (Bay)
• Lacus (Lake
• Mountains (Mountains)
• Rille (Valleys)
• Craters (Craters)
• Rays (Bause needs a rays)

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Oceanus

• Only one. Called Oceanus Procellarum (latin for
  ocean of storms)
• Basaltic lava flow (ancient 3.5 bya)
• On Western edge of near side
• 4,000,000km2

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Oceanus Procellarum
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Mare

• Several (plural is maria). Largest is Mare
  Imbrium (Sea of Showers). 1100 km diam.
• Basaltic lava flow
• 3.5 bya

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Mare Imbrium
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Mare Imbrium
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Mountains

• Lunar highlands. The lighter portion of the
  moon.
• Formed from cratering, uplifting from impact.
• Anorthsites- rocks formed from impact (type of
  glass)
• Elevations can reach 20,000 ft!!! (bigger than
  the tallest Rocky mtn)

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Apollo 15 Landing Site

• Mt. Hadley in background is 15,000 ft high!!!
• Side note
• Curvature of earth is 8 in/mile
• Moon is 48in/mile

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Rille

• Lunar canyons or valleys.
• 100s of kilometers long.
• Created by (topic is still under debate and
  research)
• Ancient lava flows
• Tectonic movement (there are no Plates on the
  Moon) caused by crater impacts.

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Ariadaeus Rille Taken by Apollo 10 flyby, 1969
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Craters

• Impact sites
• Most occurred early moon evolution.
• Young craters have rays- extension of craters.
• Best viewed near the terminator due to the low
  sun.
• Tycho is the large crater in the southern portion
  of the moon.

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Coppernicus
Tycho
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Impacts

• 1kg meteor moving 10km/s (called hypervelocity)
  releases as much energy as 10kg of TNT.
• Unlike Earth, Moon has no atmosphere to protect
  from meteors (shooting stars on Earth are usually
  caused by a particle the size of sand or a pebble
  as they burn in the atm). SO, even sand sized
  meteors make MICRO-craters.

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Fig. 8.14