mercury & the moon mercury & the moon. mercury and the moon: what can we learn? what do we...
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Mercury and the Moon: Mercury and the Moon: What can we learn?What can we learn?
What do we know?What do we know?
Why is it important?Why is it important?
Mercury and the Moon: Mercury and the Moon: What can we learn?What can we learn?
What do we know?What do we know?
Why is it important?Why is it important?
Mercury’s Impact HistoryMercury’s Impact History
Huge impact craters as well as thousands of smaller ones…
Tectonics on MercuryTectonics on Mercury
Long cliffs indicate that Mercury shrank early in its history.
http://www.nasa.gov/mission_pages/messenger/main/index.html
News from MercuryNews from Mercury
NASA’s Messenger Mission now mapping Mercury’s Surface
A great example of the process A great example of the process of science…of science…
Radio Telescope
Observations in 1990’s
A great example of the process A great example of the process of science…of science…
Radar reflects from bright spots
But is it ice??
Why Explore Mercury?Why Explore Mercury?
Learning about Earth from other planets…Learning about Earth from other planets…CoreCoreMagnetic FieldMagnetic FieldRole of Solar Energy ExposureRole of Solar Energy ExposurePlanetary ModelsPlanetary Models
NASA’s viewNASA’s view
Our MoonOur Moon
Some volcanic activity 3 billion years ago must Some volcanic activity 3 billion years ago must have flooded lunar craters, creating have flooded lunar craters, creating lunar marialunar maria..
The Moon is now geologically dead.The Moon is now geologically dead.
The Origin of the Moon: An The Origin of the Moon: An Example of the Process of ScienceExample of the Process of Science
Where did the Where did the moon come moon come from?from?
How do we How do we know?know?
How do we explain the How do we explain the existence of our Moon?existence of our Moon?
•Terrestrial planets don’t have moons….
•Our Moon is VERY large compared to its “partner”
•Composition is both like Earth…
•Rocky materials, similar to Earth’s Crust
•…and NOT like Earth:
•No water, no atmosphere, not a large metal core
How do we explain the How do we explain the existence of our Moon?existence of our Moon?
•FOUR (4) Theories
• Formed at the same time, alongside Earth
• Formed from Earth’s materials
• Captured as it passed by
• Result of Giant Impact
How do we explain the How do we explain the existence of our Moon?existence of our Moon?
•Formed at the same time, alongside Earth
•The “Sister” Theory…
•But then
•Should have the same composition…
•Should have water & “volatiles”
•Should have similar density
•It doesn’t, so rule this one out…
How do we explain the How do we explain the existence of our Moon?existence of our Moon?
•Formed from Earth’s materials
•As earth formed, it “spun out”
•“Fission Theory”
•But then…. again
•Should have water & “volatiles”
•Should have similar density
•It doesn’t, so rule this one out…
How do we explain the How do we explain the existence of our Moon?existence of our Moon?
•Captured as it passed by
•“Capture Theory”
•But then….
•How can this be done?
•It is very unlikely, so rule this one out…
Captured MoonsCaptured Moons
• The unusual moons of some planets The unusual moons of some planets may be captured planetesimals.may be captured planetesimals.
How do we explain the How do we explain the existence of our Moon?existence of our Moon?
•Result of Giant Impact
•Mars-sized impactor strikes Earth a glancing blow
• Impactor destroyed, creates a debris ring
•Gravity takes over….the Moon is born.
•Lacks “volatiles” and water & Iron
•Computer models show this to be possible!
Giant ImpactGiant Impact
Giant impact stripped matter from Earth’s crustGiant impact stripped matter from Earth’s crust
Stripped matter began to orbitStripped matter began to orbit
Then accreted into MoonThen accreted into Moon
Our MoonOur Moon
Should we go back? Should we go back?
What can we still learn?What can we still learn?
NASA Laser Communication System Sets Record with Data Transmissions to and from Moon (10/22/13)NASA Laser Communication System Sets Record with Data Transmissions to and from Moon (10/22/13)
Lunar Reconnaisance Orbiter Views (2Lunar Reconnaisance Orbiter Views (2
LCROSS Satellite wins Technology Award (2011)LCROSS Satellite wins Technology Award (2011)