Asteroid Craters

1
Asteroid Craters
By
Andrew Johnson

Roberta Peryea
2
Introduction

• Evidence of Impacts

• Mass extinctions

• Relation of size and power

3
King Crater, Far side of moon
Impacts on Mercury
Craters on Mars surface
4
Objectives

• Simulate asteroid impacts

• Calculate impact crater size

• D kEn

• Calculate size of asteroids that caused mass
  extinctions

• Compare and Contrast

5
Methodology

• Marble Drop

• Averages of different heights

b.
2. Calculate total energy

• Ek ½mv2 (total kinetic energy)
• Ep mgh (total potential energy)
• Record data

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Methodology contd
3. D kEn -- plot data on log- log graph
Figure 1.
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Data and Results
1.
1. Illustrates measuring and shape of craters.
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Data and Results contd
1. Data Table
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Contd

• Plot findings on log-log graph

Figure 1.
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Contd

• Study graph to determine values for
• a. n unknown power
• b. k unknown constant

• Apply data to equation
• a. DkEn
• D 0.0997 E0.2816

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Applications

• Understanding impact theory of mass extinctions

1st Research crater sizes
2nd Know incoming velocity rate
(4.5 million mph or 20 km/s)
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Contd
3rd Examine average densities
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Antarctic Crater Found Beneath the Ice
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Permian-Triassic mass extinction (killed
almost all life on Earth about 250 million years
ago.)

• Calculate energy of impact
• a. D 0.0997E0.2816
• b. E (D / 0.0997)1/0.2816
• E (482,800m / 0.0997)3.5511
• E 5.49x1023 Joules
• (131 million megatons )

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Permian-Triassic mass extinction contd
2. Calculate asteroid mass Ek ½mv2 m 2E
/ v2 m 2 x 5.49x1023Joules / (20,000m/s)2
m 2.75x1015kg

• Size of Permian-Triassic Asteroid
• a. 2.75x1015kg / 2,500km/m3 1.10x1012m3

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Permian-Triassic Asteroid Diameter

• V 4/3 ? r3
• d 2 (3/4 V) / ?1/3
• d 2 (3/4 x 1.1x1012) / ?1/3
• d 2 8.25x10111/3
• d 12,800m

• 13 km wide

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Asteroid Impact on the Yucatan Peninsula
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Asteroid Impact on the Yucatan Peninsula

• 125 mile wide crater that is believed to have
  caused the extinction or the dinosaurs about 65
  million years ago.

• Caused by an asteroid about 4.5 km wide

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Conclusions
1. Our results vs. the big guys

• Whered we go wrong?
• a. graphing
• b. assuming velocities
• c. assuming densities
• d. unforeseen effects

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Appendices References
Hilton, James L. Masses of the Largest Asteroids.
(1999). Retrieved October 28, 2006, from
http//aa.usno.navy.mil/hilton/asteroid_masses.htm
Meteorite Impacts. (n.d.). University of
Tennessee Department of Physics and Astronomy.
Retrieved December, 2, 2006 http//csep10.phys.utk
.edu/astr161/lect/meteors/impacts.html Murphy,
Shannon. (2005). Craters. Retrieved October 26,
2006, from http//www.astro.lsa.umich.edu/Course/L
abs/craters/cr_intro.html NuclearWeapons.
(n.d.). Retrieved December 2, 2006 from
http//academic.brooklyn.cuny.edu/physics/sobel/Nu
cphys/bomb.html Science Daily. (2006). Big Bang
In Antarctica Killer Crater Found Under Ice.
Retrieved October 28, 2006, from
http//www.sciencedaily.com/releases/2006/06/06060
1174729.htm Science Daily. (2000). Yucatan
Crater Linked To Mass Extinctions Of Dinosaurs.
Retrieved October 28, 2006, from
http//www.sciencedaily.com/releases/2000/12/00122
5061758.htm Sullivant, Rosemary. (2003). A
'Smoking Gun' for Dinosaur Extinction. Retrieved
December 2, 2006, from http//www.jpl.nasa.gov/new
s/features.cfm?feature8