Science 7 - Comets, Asteroids, and Meteors

one or more large asteroids hit the earth about ____ years ago

65 million

What is a meteoroid?

A chunk of rock or dust in space

What are comets?

A loose collection of ice, dust, and rocky particles whose orbits are very long narrow ellipses.

What is the Oort Cloud?

A spherical region that surrounds the solar system out to more than 1000 times the distance between Pluto and the sun

Where do most asteroids revolve?

Around the sun, between the orbits of Mars and Jupiter. (Asteroid belt)

what is the Kuiper belt?

Doughnut shaped region that extends from beyond Neptune's orbit to about 100 times Earth's distance from the sun

A doughnut-shaped region of comets that begins near Neptune's orbit is the ___

Kuiper belt

what are the two distant regions?

Kuiper belt and the Oort Cloud

A spherical region of comets is the __

Oort Cloud

A rocky object that revolves around the sun, but is too small to be considered a planet is a ___

asteroid

The region of the solar system between the orbits of Mars and Jupiter is known as the...

asteroid belt

how were the craters on the moon formed?

by meteoroids

clouds of gas and dust on a comet form a fuzzy outer layer called a __

coma

A chunk of ice and dust whose orbit is usually a long narrow ellipse is a...

comet

meteoroids come from...

comets or asteroids

smaller objects are...

comets, asteroids, meteoroids

nickname for a comet:

dirty snowball

4 parts of the comet:

head, nucleus, coma, tail

comet's head:

made from coma and nucleus

comet's coma:

made up primarily by gasses

scientists hypothesize that... (extinct dinos)

many species of organisms, including the Dinos, became extinct as a result of many asteroids hitting the earth

When a meteoroid enters Earth's atmosphere, friction causes it to burn up and produce a streak of light called a ___

meteor

If a meteoroid hits the Earth's surface, it is called a ____

meteorite

Meteoroids that pass through the atmosphere and hit earth surface are...

meteorites

A chunk of rock or dust in space that usually comes from a comet or an asteroid is called a ____

meteoroid

inner core of the comet is the...

nucleus

Most comets are found in...

one of two distant regions

when a meteor enters Earth's atmosphere, friction with the air creates heat and...

produces a streak of light that you can see in the sky-- a meteor

asteroids are too ___ to be considered planets

small and numerous

a comet's tail is _____ and can be more than __________

stretched very thinly/100 million kilometers long

clouds of gas and dust form a fuzzy outer layer called...

the coma

How does the tail of a comet form?

the comet heats up as it approaches the sun