2: Meteorite Impacts

Question 1

Extraterrestrial Objects

Answer 1

Asteroids
Comets
Metoroids

Question 2

Asteroids

Answer 2

10m to 1000km
Metallic or rocky
Most originate in the asteroid belt between Mars and Jupiter

Question 3

Comets

Answer 3

Few m’s to few hundred km’s
“Dirty snowballs” - frozen water and or carbon dioxide + rock fragments
Trails - vapor and dust shed from object
Most originate in outer solar system (Oort Cloud and Kupler belt

Question 4

Meteroids

Answer 4

<10m to dust

Produced from the collision of asteroids

Question 5

Meteors

Answer 5

enter Earth’s atmosphere

Question 6

Meteorites

Answer 6

Impact Earth’s surface

~35000 tons/yr of meteoritic material lands on Earth

Question 7

Impact Craters

Answer 7

Plenty of extraterrestrial examples

Not so common on Earth because of tectonics and erosion

Question 8

Permian-Trassic Extinction

Answer 8

75% of all species went extinct (96% of all marine species, 70% of terrestrial vertebrates)
A candidate crater in Antarctica was discovered just a few years ago

Question 9

Cretaceous-Tertiary extinction

Answer 9

Extinction of dinosaurs and other species

Question 10

Cretaceous-Tertiary exctinction: 1980

Answer 10

Worldwide occurrence of Iridium-rich marine clay deposits at the boundary (Ir is rare in terrestrial rocks but enriched in meteorites)

Question 11

Cretaceous-Tertiary exctinction: 1994

Answer 11

Large buried impact crater of the right age was found on the Yucatan Peninsula in Mexico

Question 12

Close approaches of near-Earth asteroid 99942 Apophis (future years?)

Answer 12

2029 and 2030