Earth's Moon

SMART-1Small Missions for

Advanced Research in Technology

A look at our nearest neighbor in Space!

The Moon

What is the Moon?

• A natural satellite• One of more than

96 moons in our Solar System

• The only moon of the planet Earth

Moon’s Location from Earth

• About 384,000 km (240,000 miles) from Earth

• 3,468 km (2,155 miles) in diameter (about ¼ the size of Earth)

A Brief History of Lunar Exploration• 1959: Soviet Lunas 1, 2, 3 orbited around Moon

• 1960’s: US Ranger - flyby mission- first space pictures- many TV cameras

• 1966-67: Lunar Orbiter- 5 orbiting spacecraft- full coverage of pictures

• 1966-68: Lunar Surveyor- surveying for landing sites - testing the “soil” (sink?)

Highlights from Apollo 11 missionlaunch: July 16th 1969arrival at Moon: July 20th 1969first humans to land on the Moon

Command Module (CM):“Columbia”

13 Oct 2003 Solar System - Dr. C.C. Lang 7

On July 20, 1969, after a four day trip, the Apollo astronauts arrived at the Moon. This photo of Earthrise over the lunar horizon is one of the most famous images returned from the space program, although even the astronauts themselves cannot remember who actually took it.

13 Oct 2003 Solar System - Dr. C.C. Lang 8

First steps on the Moon• July 20th 1969

- Neil Armstrong- “Buzz” Aldrin

Touchdown of Moon astronauts near the coast of Hawaii on July 26th 1969

Earth

• Active wind/water erosion

• Impacts

• Active volcanoes

• Earthquakes

• Active magnetic field

• Few craters

Geologically Active!

Moon

• NO Active wind/water erosion

• Impacts

• NO active volcanoes

• Small moonquakes

• NO active magnetic field

• Buckets of craters

Geologically Inactive!

Earth

Plate tectonic

s!

Moon

NO plate tectonics

Earth Moon

HOT! Not so hot!

Why so different?

3 Layers of the Moon1) Crust - average

thickness of about 70 kilometers

2) Mantle3) Core - radius is

between 300 and 425 kilometers

The Moon’s Surface• No atmosphere• No liquid water• Extreme

temperaturesDaytime = 130C Nighttime = -190C

• 1/6 Earth’s gravity

Lunar Features

Highlands

• Mountains up to 7500 m (25,000 ft) tall

• Rilles (trenchlike valleys)

Lunar Features

Craters

• Up to 2500 km (1,553 miles) across

• Most formed by meteorite impact on the Moon

• Some formed by volcanic action inside the Moon

Lunar Features

Maria

• Originally thought to be “seas” by early astronomers

• Darkest parts of lunar landscape

• Filled by lava after crash of huge meteorites on lunar surface 3-4 billion years ago

• Mostly basalt rock

Maria

CratersCan you see the rays?

Movements of the Moon

• Revolution – Moon orbits the Earth every 27 1/3 days

• Rotation – Moon turns on its axis every 27 days

Movements of the Moon• The moon rises in the

east and sets in the west

• The moon rises and sets 50 minutes later each day

• Same side of Moon always faces Earth

Far Side of the Moon• First seen by Luna 3

Russian space probe in 1959

• Surface features different from near side–More craters–Very few maria–Thicker crust

Lunar Formation ModelsThe moon is a sister world that formed in orbit around Earth as the Earth formed.

The moon formed somewhere else in the solar system then was captured into orbit around Earth.

Early Earth spun so fast that it spun off the moon.

Impact by Mars-sized proto-planet

4.5 billion years ago

Copyrighted, LPI

Copyrighted, LPI

Copyrighted, LPI

Copyrighted, LPI

Copyrighted, LPI

Lunar Geologic History

4.5 billion years ago, our Moon forms (lunar rocks and meteorites)

Lunar Geologic History

Copyrighted, LPI

Copyrighted, LPI

Magma Ocean Rocks

60025Anorthosite4.44-4.51 Ga95% Plag Feld (anorthite)Magma Ocean!No Water!

76535Troctolite

4.2-4.3 Ga

Highlands - light, rough (Terrae)

Mostly anorthosite

(plagioclase feldspars - lots of calcium and aluminum)

“In place” rocks are 4.5 to 4.3 billion years old

BIG Dark areas?

Lunar Geologic History

Lunar Impact Basins

Imbrium Rim Orientale Basin

Big, frequent impacts until 3.8 billion years agoImpact events continue on all moons and planets today

Tycho Crater

Young – 100 MY85 kilometers

acrossFresh (rays) =

young

Rim

Ejecta

Central Peak

Floor Wall

Rays

Impacts …“the most fundamental process on the terrestrial planets…” Eugene and Carolyn Shoemaker

Breccias and Impact Melts

15445Impact melt + clasts

67016Polymict Breccia

Lunar Geologic History Mare Volcanism

SW Mare ImbriumMare Imbrium

Volcanism after impacts – most before 3 Ga (to 1 Ga)

Lunar Volcanism

Aristarchus Plateau

Marius Hills

Lava Tubes

Apollo 17

Lunar Basalts15555

15016

3.3 Ga

Lowlands – dark, smooth Maria (16%)

Basalt – fine grained dark igneous rock rich in iron and magnesium (stuff that sank in magma ocean)

Few hundred meters thick

Rocks are 4.3 to 3.1 billion years old … volcanic flows as recently as 1 billion years ago!!

Lunar Geologic History

And then ….

All was quiet.

• Except for impacts...

7 November; ~30 lb TNT3 m-wide crater (estimate)

• No Wind• No Flowing Water• No Erosion

• Except for impacts...

Return to the Moon!• 2012 – Develop and test

technologies for resource utilization, communications, power

• 2014 – CEV, Ares launch vehicle

• 2018 – Humans for week-long stays• Next: 45-day stays at outposts

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