Impacts of Meteors

• Meteor: Glowing fragments from outside the atmosphere that burn upon entry

• Meteorite: Piece of rock that strikes earth from space

• Asteroid: Small solar system bodies orbiting around the sun

Yao YaoDina Freedman10.25.11

Frequency: graph

MeteoritesVelocity: typically 10 to 70 km/s when entering atmosphere

Large

SmallSlow down to “almost nothing”, same velocity as an object dropped from a plane

Reach the ground with high velocity,result in a crater

Nelson, 2010

Kinetic Energy and Power

• Meteorite Flux =10⁷- 10⁹ kg/year

• Escape Velocity= 11 km/s

• KE = ½ * 10⁸kg * (1.1*10⁴ m/s)²

• =6.05 * 10¹⁵ Joules

• Power = 6.05 * 10¹⁵ Joules/ 3.1536 * 10⁷ s

• Power=1.92*10⁸ W or 1.92 *10⁵ kW

• An average house uses 1.8 kW

50m 250m 500m 2500m 5000m0.00E+00

2.00E+06

4.00E+06

6.00E+06

8.00E+06

1.00E+07

1.20E+07

Diameter and Energy

Diameter of the meteorites

Ener

gy in

meg

aton

s of T

NT

1.3E+06 megatons

1.1E+07 megatons

10 megatons

0.1 megatons

Historical Impacts

• The KT extinction 65 MYA created the Chicxulub Crater about 180 km in diameter

• The 1908 Tunguksa Siberia meteor knocked down trees for about 850 sq. miles but did not leave a crater