Asteroid Impacts

1. Asteroid Impacts Chapter 39.10

2. Standard 1f • 1f: Students know the evidence for the dramatic effects that asteroid impacts have had in shaping the surface of planets and their moons and in mass extinctions of life on Earth.

3. Asteroids, Meteors, & Meteorites, oh my! • Asteroid: Small rocks that orbit the sun (located at the asteroid belt) • Meteor: Small rock that strikes the Earth’s atmosphere • Meteorite: Any meteor that reaches the Earth’s surface

5. Asteroid Belt

7. Meteor Shower

8. Meteor Shower

9. Meteorites

10. Meteorite Effect • Meteors hit the Earth’s atmosphere all the time, but many burn up in the Earth’s atmosphere • Meteors that do hit (meteorites) are usually small with no or minor damage

11. Some Examples… • On November 30, 1954, Alabama housewife Ann Hodges was taking a nap on her couch when she was awakened by a 3-pound (1.4-kilogram) meteor that crashed through the roof of her house, bounced off a piece of furniture and struck her in the hip, causing a large bruise. • On October 9, 1992, a large fireball was seen streaking over the eastern United States, finally exploding into many pieces. In Peekskill, New York, one of the pieces struck a Chevrolet automobile owned by Michelle Knapp. Knapp was not in the car at the time, but heard the crash and ran out to her driveway to find a hole punched clear through the trunk of her car and a warm 26-pound (12-kilogram) meteorite lying under the vehicle. But things turned out well in the end -- her old and rather run-down automobile instantly became a collectors item and later sold for tens of thousands of dollars. • On June 21, 1994, Jose Martin of Spain was driving with his wife near Madrid when a 3-pound (1.4-kilogram) meteor crashed through his windshield, bent the steering wheel and ended up in the back seat. Martin suffered a broken finger while his wife was uninjured.

12. Meteorite (New York, 1992)

13. Meteorite Effect • Some meteorites are big enough and can cause major damage • Evidence of meteor damage can be seen by craters

14. Craters

15. Craters

16. Crater Impact • Impacts of asteroids have created extensive cratering on the Moon, on Mercury, and on other bodies in the solar system.

20. Meteorite Impact on Earth • It is believed that a meteorite hit the Earth at about 65 million years ago. • Evidence is shown by an unusual rock layer that suggests that entire Earth was covered in dense smoke. • This event may have been ultimately responsible for the mass extinction of dinosaurs and many other species.

24. Asteroid Impact on Earth? • Because of the Sun’s gravity, there are asteroids that come close to the Earth’s orbit, but never crosses it

25. Asteroid “Eros”