earth's moon
TRANSCRIPT
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
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
