Comets, Meteoroids, Asteroids

A comets tail

As the comet approaches the sun and heats up, some of its gas and dust stream outward forming a tail. Comet means long-haired star. Most comets have two tails, a gas tail and dust tail. Both tails usually point away from the sun. The tail can be more than 100 million kilometers long.

Comets

Comets are basically large, dirty snowballs. They are loose collections of ice, dust, and small rocky particles whose orbits are usually very long and narrow ellipses.

Asteroids

Huge chunks of rock usually found between Mars and Jupiter are called asteroids. The region of asteroids between Mars and Jupiter is called the Asteroid Belt. Scientists hypothesize that asteroids are pieces left over from the early solar system that never formed planets.

Meteoroid

Meteoroids are chunks of rock or dust in space. Meteoroids can come from asteroids or comets. Some meteoroids form when asteroids collide in space. Others form when comets break up and create a cloud of dust that continues to move through the solar system.

Size of Asteroids

Most asteroids are less than 1 km in diameter, only Ceres, Pallas and Vesta are bigger than 300 km in diameter.

orbits of asteroids

Some asteroids have very elliptical orbits that bring them closer to the sun then Earth's orbit. Someday one of these asteroids could hit.

Kuiper Belt

The Kuiper Belt is a doughnut shaped region that extends from beyond Neptune's orbit to about 100 times Earth's distance from the sun.

Oort cloud

The Oort cloud is a spherical region of comets that surrounds the solar system out to more than 1,000 times between the distance of Pluto and the sun.

Asteroid Belt

The biggest asteroids in the asteroid belt are Ceres, Pallas, Juno and Vesta. Astronomers have discovered more than 100,000 asteroids and they are constantly finding more.

A comets head

The head is the brightest part of a comet made up of the nucleus and coma.

Nucleus

The solid inner core of the comet.

Coma

When comets get close enough to the sun, the energy from the sun turns the ice into gas, releasing gas and dust. Clouds of gas and dust form a fuzzy outer layer called a coma.

Meteors, Meteoroids, meteorites

When meteoroids enter Earth's atmosphere, friction with the air creates heat and produce a streak of light in the sky (a meteor) as they burn up. Meteoroids that are large enough to pass through the atmosphere and not burn up and hit Earth are called meteorites. The moons craters were formed by meteoroids.

Origin of comets

most comets originate in one of these two distinct regions of the solar system: the Kuiper belt or the Oort cloud.