Transcript Space Rocks - American Geosciences Institute

Space Rocks
Impacts of our smallest neighbors
1
Asteroid
Asteroid
Belt
Belt
2
Primitive Solar System
The four inner planets formed,
but Jupiter’s huge gravity caused
chaos in the region past Mars.
No big planet ever formed there
3
Craters in the Inner
Solar System
Mercury
Mars’s Southern Highlands
4
Impacts
on Moons
Mars’s tiny moon Phobos
Mimas, a moon of Saturn
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Lunar Cratering
Our Moon
shows a
history of
impacts
Most of these
occurred long
ago…
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The Asteroid Belt is Sparse
On average, there are
more than 1 million km
between asteroids
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Dynamic
Collisions
Do
Occur
And the effects
are seen
throughout the
Solar System
9
Jupiter Shows Recent Impacts
The world watched as a
comet collided with
Jupiter in 1994
Possibly not as rare as we
thought. Other collisions
have occurred since, like
this one in 2009
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More than 170
Impact Craters on Earth
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Earth Erases
History of Impacts
Barringer Crater, Arizona
Roter Kamm, Namibia
Wolf Creek, Australia
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Chicxulub and the Dinosaurs
13
Recent Earth Impacts
2008 TC3- first celestial object
tracked by astronomers before
entering Earth’s atmosphere
Tunguska in Russia 1909
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Meteorites
Chunks of asteroids sometimes make it through
the atmosphere to the ground
These are time capsules telling us about how
matter came together in the early Solar System
15
Future Impacts
• Meteoroids smaller than a house
will explode in our atmosphere
5-10 meter objects hit about once a year
• Larger objects are rare but devastating
We don’t know when the
next big impact will happen,
but it will eventually
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Can we Stop an Impact?
Our best chance of avoiding
an impact is having
advance notice of a threat
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NASA’s
WISE Mission
Using Infrared
technology to see
dark asteroids

WISE finds asteroids - including
some seen for the first time
 100,000s of Main Belt Asteroids
 100s of Near-Earth Objects
(NEOs)
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The Challenge Could be Ours
If we do find an asteroid headed for Earth…
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