Part 1: Formation & Evolution of the Moon Part 2: Lunar Libration
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Transcript of Part 1: Formation & Evolution of the Moon Part 2: Lunar Libration
• Part 1: Formation & Evolution of the Moon
• Part 2: Lunar Libration
• Part 3: The Eastern Seas
The Moon’s Eastern Seas
Geologic timeline of Earth
1800 First Complex single-cell life
380 First Vertebrate Land Animals230-65 Dinosaurs
80-55 Rocky Mts. Uplift
0.0117 Glaciers Retreat
4570 Earth Formation
Geologic timeline of Moon & Earth
4570 Earth Forms
4533 Moon Forms from Giant Impact
Formation & Evolution of the Moon
Late Heavy Bombardment
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SProcellarum
Insularum
Marginis
Fecunditatis
Australe
Tranquillitatis
Nubium
Smythii
Grimaldi
Pre-Nectarian
Nectaris, Humboldtianum, Humorum, Crisium, Serenitatis
Nectarian
Lava Flows
Pythagoras, Theophilus, Langrenus, Hercules
Tycho, Aristarchus, Kepler
NOW
Surface Hardens
Imbrian Eratosthenian Copernican
Timeline for Lunar Lava Flows
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Pre-Nectarian
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Lunar Volcanic ActivityNOW
Beginning of the Late
Imbrian Period
Drawing by
Don Davis
End of the Late
Imbrian Period
Drawing by
Don Davis
Present Day Moon
Drawing by
Don Davis
Lunar Libration
Lunar Directions
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The Eastern Seas
In early February the 6-day-old Moon was Librated so that more of the eastern area was visible than usual.
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Mare Humboldtianum
Mare Humboldtianum
Located in the Moon’s NE Corner
Outer Basin is 600 Km in Diameter
Formed during the Nectarian Period
Inner Basin & Mare are 300 Km in Diameter
The Basin formed during the Nectarian Period, and filled with lava during the Late Imbrian
Named for Alexander von Humboldt by
Johann H. Mädler
Late Heavy Bombardment
Lunar Periods
Alexander von Humboldt
• (September 14, 1769 – May 6, 1859) was a Prussian geographer, naturalist and explorer. Humboldt's quantitative work on botanical geography laid the foundation for the field of biogeography.
Johann Heinrich von Mädler
(May 29, 1794 – March 14, 1874) one of the great and eminent astronomers of the 19th century. Has a crater on the Moon and one on Mars named for him.
Mare Smythii,
Mare Smythii• One of the lowest Maria, 4 – 4.5
Km below the avg. Lunar Surface• Impact basin is Pre Nectarin, 350 -
400 Km in diameter• Southern floor is late Imbrian
basalt. Northern floor is from the Eratosthenian period & may be only 1 – 2 billion years old.
Named for Admiral William Henry Smyth (21 Jan. 1788 – 8 Sep.1865), English naval officer & astronomer. President Royal Astronomical Society. Published Bedford Catalogue with observations of 1604 double stars and nebulae (with a 5.9-inch refractor).
Mare Marginis
Mare Marginis (The Sea of the Edge)
• Thought to be one of the oldest Maria on the Moon. About 200 Km north-to-south.
• Apparently not area with a major impact basin. Appears to be a low-lying area where lava filled several cratered areas where the lunar crust was relatively thin. The lava flows are also thin, being only an estimated 1000 to 1700 feet thick.
• The highland area is Pre-Nectarian and lava flows are probably Late - Imbrian
Mare Anguis, Undarum & Spumans
Mare Anguis
• All three Maria are of Nectarin origin, with lava filling them during the Late Imbrian Period.
Mare Undarum Mare Spumans
(Serpent Sea)
(150 Km long)
(Sea of Waves)
(240 Km dia.)
(Foaming Sea)
(140 Km dia.)
Mare Australe (The Southern Sea)
• This 600 Km heavily-cratered basin was formed during the pre-Nectarin period, and filled with lava during the late Imbrian period.
• The basin is located in the Southeast area of the moon, and half of the basin is on the far side, but can be seen (barely) during favorable librations.
References• The Modern Moon – a personal view
– By Charles A. Wood
• The Geologic History of the Moon (US Geological Survey Professional
Paper 1348) –By Don E. Wilhelms
• Wikipedia• “Eastern Seas” photo taken with 6” f/8
Refractor at prime focus, Canon Rebel DSLR, ISO 100, 1/250th second
• http://www.lpod.org/cwm/DataStuff/pronounce/Introduction.htm
The End!
Questions?