Comets, asteroids, meteors
- 1. A. Comet: dust and rock particles combined with frozen water, methane, and ammonia.
- 2. 1. Halley’s comet: orbits Sun every 76 years.
- 3. 2. Oort Cloud: large group of comets surrounding solar system beyond Pluto.
- 4. 3. Amateur astronomers discovered Hale-Bopp in 1995.
- 5. 4. Comet structure: large dirty snowball of frozen rock and ice.
- 6. Comets a. Ice and dust vaporize as comet nears Sun. b. Vaporized material forms bright cloud called coma around comet nucleus. c. Solar wind pushes on gas and dust in the coma, causing the particles to form a tail that always points away from the Sun. d. Eventually, most of the ice in the comet’s nucleus vaporizes, leaving only small particles.
- 7. Comets vaporize and break up after passing close to the Sun several times. When the nucleus breaks up, pieces spread out. The dust and rock fragments are called Meteoroids .
- 8. B. (1.) Meteoroid : name given to small pieces of comet when they move through space.
- 9. B. (2.) Meteor : small meteoroid that burns up in Earth’s atmosphere.
- 10. B. (3.) Meteor Showers : occur when Earth’s orbit passes through a group of meteoroids that enter the atmosphere.
- 11. B. (4.) Meteorite : meteoroid that strikes Earth.
- 12. C. Asteroid : rock similar to that which formed planets.
- 13. C. (1.) Most asteroids lie in an asteroid belt located between Mars and Jupiter.
- 15. Asteroid Info: Jupiter’s gravity may have kept these asteroids from forming a planet. some planets’ moons may be asteroids pulled from the asteroid belt. asteroid sizes range from very tiny to 940 km in diameter.
- 16. Near: The Near Earth Asteroid Rendezvous probe indicates asteroid 433 Eros has been in many collisions over time.
- 17. What is a shooting star? It is NOT a star!!
- 19. Shooting Star: A meteor that is burning up in the Earth's atmosphere. A.K.A. a Meteor!!