A. Comet: dust and rock particles A. Comet: dust and rock particles combined with frozen water, combined with frozen water,

methane, and ammonia.methane, and ammonia.

1. Halley’s comet: orbits Sun 1. Halley’s comet: orbits Sun every 76 years.every 76 years.

2. Oort Cloud: large group of 2. Oort Cloud: large group of comets surrounding solar system comets surrounding solar system

beyond Pluto.beyond Pluto.

3. Amateur astronomers 3. Amateur astronomers discovered Hale-Bopp in 1995.discovered Hale-Bopp in 1995.

4. Comet structure: large dirty 4. Comet structure: large dirty snowball of frozen rock and ice.snowball of frozen rock and ice.

CometsCometsa. Ice and dust vaporize as comet nears a. Ice and dust vaporize as comet nears

Sun.Sun.b. Vaporized material forms bright cloud b. Vaporized material forms bright cloud

called coma around comet nucleus.called coma around comet nucleus.c. Solar wind pushes on gas and dust in c. Solar wind pushes on gas and dust in

the coma, causing the particles to form a the coma, causing the particles to form a tail that always points away from the Sun.tail that always points away from the Sun.

d. Eventually, most of the ice in the d. Eventually, most of the ice in the comet’s nucleus vaporizes, leaving only comet’s nucleus vaporizes, leaving only small particles.small particles.

Comets vaporize and break up Comets vaporize and break up after passing close to the Sun after passing close to the Sun

several times. When the nucleus several times. When the nucleus breaks up, pieces spread out. The breaks up, pieces spread out. The dust and rock fragments are called dust and rock fragments are called

MeteoroidsMeteoroids..

B. (1.) B. (1.) MeteoroidMeteoroid: name given to : name given to small pieces of comet when they small pieces of comet when they

move through space.move through space.

B. (2.) B. (2.) MeteorMeteor: small meteoroid : small meteoroid that burns up in Earth’s that burns up in Earth’s

atmosphere.atmosphere.

B. (3.) Meteor ShowersB. (3.) Meteor Showers: occur when Earth’s : occur when Earth’s orbit passes through a group of meteoroids orbit passes through a group of meteoroids

that enter the atmosphere.that enter the atmosphere.

B. (4.) B. (4.) MeteoriteMeteorite: meteoroid that : meteoroid that strikes Earth.strikes Earth.

C. C. AsteroidAsteroid: rock similar to that : rock similar to that which formed planets.which formed planets.

C. (1.) Most asteroids lie in an C. (1.) Most asteroids lie in an asteroid belt located between Mars asteroid belt located between Mars

and Jupiter.and Jupiter.

Asteroid Info:Asteroid Info:Jupiter’s gravity may have kept these Jupiter’s gravity may have kept these

asteroids from forming a planet.asteroids from forming a planet.some planets’ moons may be asteroids some planets’ moons may be asteroids

pulled from the asteroid belt.pulled from the asteroid belt.asteroid sizes range from very tiny to 940 asteroid sizes range from very tiny to 940

km in diameter.km in diameter.

Near: The Near Earth Asteroid Rendezvous Near: The Near Earth Asteroid Rendezvous probe indicates asteroid 433 Eros has been probe indicates asteroid 433 Eros has been

in many collisions over time.in many collisions over time.

What is a shooting star?What is a shooting star?

It is NOT a star!!It is NOT a star!!

Look Familiar??????Look Familiar??????

Shooting Star:Shooting Star:

A meteor that is burning up A meteor that is burning up in the Earth's atmosphere. in the Earth's atmosphere. A.K.A. a Meteor!!A.K.A. a Meteor!!