Comets and Asteroids

By: Cole Johnson

Comet Section

- Comets are small bodies in our solar system that show a thin, hazy atmosphere and usually a tail when they are close enough to the sun.

- Where do Comets form ? Well where comets form depends upon the period of their orbit. So comets with shorter orbital periods come from a part of the solar system called the scattered while the comets with longer orbital periods are believed to come from the Oort cloud.

When did comets form ? about 4.6 billion years ago

How do comets form ? They form from the material left over from the formation of the planets.

- In the Solar system, all of the Planets ( Mars, Earth Venus, etc. ) orbit in a counter-clockwise direction while comets orbit in the opposite direction.

- Comets have tails because as they approach perihelion ( place in their orbits when they are closest to the Sun ) the Sun's heat vaporizes some of the comets material, releasing dust particles that were trapped in ice.

- The picture on the upper right of the page is the Hyakutake comet. This picture was taken by the Hubble Space Telescope on April 4, 1996.

Comet Video

The video below talks about comets, how and where they orbit, how they are compared to asteroids, and how they form tails. Facts that you may see in the video are "Comets are created in the deepest reaches in the Solar system" and "Sublimation is the process of making a tail for the comet. One vocabulary word in the video that you may hear is "vaporized", vaporized is to be convert or be converted into vapor. The creator of this video is the "History" channel, company.
The Universe: Comets

Asteroid Section

- An asteroid is a small rocky body orbiting the sun.

- A meteor is a flash of light that we see in the night sky when a chunk of interplanetary debris burns up as it passes through our atmosphere. The debris is called a meteoroid and an asteroid is a small rocky body orbiting the sun.

- A "near-Earth asteroid" is an asteroid that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighborhood.

- About 2 billion years ago the Vredefort Crater which had an estimated radius of 118 miles crashed in Free State, South Africa. This made it the world's largest known impact structure.

-The picture below is the Ida Asteroid, this photo was taken by the imaging system on the Galileo space craft.

Big image

Asteroid News/Article

This article is about how earth is vulnerable to asteroid strikes as every decade. This news was provided by "The New York Times".