IT%20CAME%20FROM

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IT CAME FROM
OUTER SPACE

• Asteroids, comets, and YOU

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Formation of the Solar System
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Formation of the Moon
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Luna
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The Asteroid Belt is not like this
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Chicxulub 65 million years ago 180 km wide
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Barringer Meteor Crater (Arizona) 49,000 years
ago 1.186 km diameter (0.737 miles)
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Area surrounding the 1908 Tunguska Event, circa
1927
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Artists Conception, just before impact
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(No Transcript)
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When will the next collision occur?
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2029 Orbit-changing encounter
Asteroid 99942 Apophis Size 300
meters Probabilty of Collision in 2036 1 in
45,000 (as of last year)
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Factors important in asteroid collisions
Planetary Gravity gplanet 9.8 m/s
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Target Density Rocky Crust ? 2700
kg/m3 (Water ? 1000 kg/m3)
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Impactor Density Density ? 3000 kg/m3
max Comet ? 300-700 kg/m3
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Kinetic Energy KE ½mv2 vmeteor 10 - 40 km/s
(assume 30)
Angle of Impact Most common 45
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Equation for Radius of Impactor from De Pater and
Lissauer (2001)
0.401
(?planet)0.42
(Dcrater)1.28
(gplanet)0.28
(2700)0.42
(9.805)0.28
2.2610-3
Rmeteor
(vmeteor)0.56
(?meteor)0.42
(3000)0.42
(30000)0.56