Bell work

Have scientists ever brought extraterrestrial material to Earth? Scientists have studied rocks from Mars and other parts of the solar system. How have scientists obtained these rocks?

Record your answer in your science journal.

Comets, Meteors, and Asteroids

Today’s Objectives

Explain why comets, asteroids, and meteoroids are important to the study of the formation of the solar system.

Describe the similarities of and differences between asteroids and meteoroids.

Explain how cosmic impacts may affect life on Earth.

Comets

Small body of ice, rock and dust loosely packed together that orbits the sun

A comet is a “dirty snowball” about the size of an earth mountain. (dirt and ice)

Comets’ orbits are usually very long, narrow ellipses. They produce tails of gas and dust when they

approach the sun. Look like “shooting stars” but can move much

slower.

Comet Parts Tails

Ion-electrically charged ions, always points away from the sun

Dust- follows the orbit of the cometGas-follows the orbit of the comet alsoCan extend millions of km

Comet Parts Nucleus

Averages 3 miles in diameter, by can be between ½ and 100 km

Solid, rocky, icy centerShows different features as it nears the

sunComa forms a large halo around the

nucleus of a comet as it nears the sunThe Coma’s halo is made of dust and gas

Structure of a Comet

To Sun

Ion Tail

Dust Tail

Coma

Orbit

Highly elongated Very elliptical

Oort Cloud

Oort cloud- Oort cloud- sphere that sphere that surrounds the surrounds the solar system 1 solar system 1 light year away light year away from the sun from the sun made of dust and made of dust and gasgas

The Oort Cloud

Kuiper Belt- outside orbit of Neptune- made of dust and rocks- Kuiper Belt- outside orbit of Neptune- made of dust and rocks- where most dwarf planets are found.where most dwarf planets are found.

Comet names

Comets are often named after the person who discovers them!

Maybe the next one could be named after you!

Comet Halley

Comet Halley 1910

•Pope Callixtus III excommunicated Halley's Comet in 1456

•In 1910, charlatans sold "comet pills"

Orbit

Halley’s Comet (1986)

Halley’s Comet…. Orbits every 76 years

Hyakutake

Comet: Hale-Bopp

Winter and early spring of

1997

Next sighting: 4380

www.brainpop.com/science/space/comets/

Hale-Bopp

Comet West

Today’s Objectives

Explain why comets, asteroids, and meteoroids are important to the study of the formation of the solar system.

Describe the similarities of and differences between asteroids and meteoroids.

Explain how cosmic impacts may affect life on Earth.

Meteoroid- small rocky body often made of rock,

metal, or dust. Meteorite- meteoroid that hits the Earth

Meteoroids survive as they pass through the atmosphere and hit Earth’s surface

Meteor- meteoroid that burns up in the Earth’s atmosphere Shooting stars are not actually stars. These flashes of light across

the sky are small bits of rock burning up in the Earth’s Atmosphere. They often move very fast across the sky.

They are called “fireballs” when it creates a long streak of light as it gets close to the ground.

Meteoroids, Meteorites, and Meteors

3 types Stony Metallic Stony-iron

The Cause of Meteor Showers

P55/Tempel-Tuttle

The 1833 storm

The 1966 storm

1997 Leonids from Orbit

Two Showers for Halley

Sporadic Meteors

Irons Stony-Irons

Chondrites Carbonaceous Chondrite

Achondrite

Barringer’s Crater

An iron meteorite 100 feet across and 70,000 tons slamed into the Earth at about 43,000mph in the Arizona desert near Flagstaff 40,000 years ago. Barringer Crater is 4,100 feet wide and 571 feet

deep.

Other Impact Craters

METEOROID: A piece of stone or metal that travels in outer space.

METEOR: An object from space that becomes glowing hot when it passes into Earth's atmosphere.

METEORITE: A piece of stone or metal from space that falls to Earth's surface.

SUMMARY

Today’s Objectives

Explain why comets, asteroids, and meteoroids are important to the study of the formation of the solar system.

Describe the similarities of and differences between asteroids and meteoroids.

Explain how cosmic impacts may affect life on Earth.

Asteroids

Small rocky bodies in orbit around the sun. (larger than meteoroids)

Have the same compositional matter as the Terrestrial planets

Located between Mars and Jupiter in the Asteroid Belt.

Ceres was the largest asteroid ever discovered Now it is classified as a Dwarf Planet!

Asteroids

Apollo

Trojans

Ida - Dactyl

Gaspra

Today’s Objectives

Explain why comets, asteroids, and meteoroids are important to the study of the formation of the solar system.

Describe the similarities of and differences between asteroids and meteoroids.

Explain how cosmic impacts may affect life on Earth.