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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ISIM

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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?