COMETS AND ASTEROIDS

Casey Witthohn
English 11R-9
Elberth

A quick look at the scarred face of the moon provides evidence enough to see that space is not an empty place. Small bodies of rock and frozen materials are traveling around space at all times. As far as scientists can tell, they have been since the dawn of time. These space rocks are known as asteroids, comets, and meteors. Usually, people look at them as a work of art, or a phenomenon, until they come too close. Every few years a comet hits the earth with enough impact to topple trees. These are meteorites.
Asteroids were once dismissed as the rodents of the sky. They have different colors and spin periods than any other space rocks. They are generally small rocks in comparison to the rest of space bodies, but vary from the size of bird house, to the size of a small piece of real estate. Asteroids usually travel in groups and sometimes form asteroid belts that can wrap around an entire solar system. There are about 150 known asteroids that travel in a path near the earth, and they are actually called, "near-earth" asteroids. About 10 percent are bound to hit earth eventually.
Asteroids ranging from fine dust, to house size rocks make up the belt around Saturn, and the belt on the outside of the orbit of Mars. These are pieces of larger rocks that were crashed into the remaining pieces after millions of years of crashes.
Each ring system has distinctive features. Jupiter's rings are tenuous and made mainly of dark particles the size of those in cigarette smoke. The bright rings of Saturn are made of mainly frozen water in the form of snowballs and chunks of ice. Saturn has thousands of rings, some twisted, showing off dusty, spooky markings that form and change constantly. The dark rings of Uranus seem to be made of charcoal or smokey materials. Uranus has nine main rings, a few seem to breathe moving and expanding, then pulling back in.
The rings are formed when a comet or asteroid sails very near the surface, tearing off pieces that fly away and are slowed and caught in the gravity of the planet, then spread out. Another way is when moons are collided or collided into by a large piece of space matter and are shattered and spread out forming rings.
Comets are bits and pieces of planets that smashed together. They sometimes possess the pieces and materials from the dawn of our solar system. Comets have brightness and size variation due to the amount of dust being put off as it floats around space at speeds that could outrun a bullet. Comets follow a reasonably tight schedule in a big loop of passing from one solar system or star's gravity, to the next. Scientists can predict with reasonable accuracy how long it will take to come back around. It is not absolute, however. Things like "jetting" can change the course of the comet. "Jetting occurs because the ice on eh comet contains methane and other volatile gasses. When the portion of the comet facing the sun is heated, the ice tends to erupt, sending off a jet of material streaming off the comets surface." As said by Jim Dawson of the Star Tribune. Due to the fact that the jet stream is toward the sun it pushes the comet into a larger orbit. Other things like dust change the course of the comet due to the fact that it is a small form of resistance that may slow the comet over time. An astronomer, Terry Jones, says "Comets don't last forever. They are either thrown out of the solar system, they break up, or they run into something."
If a comet were to get too close to earth, it is called an "error box" which translates to bad news. That is when the possibility of a collision may occur. If a comet were to hit the earth, it would be approximately the same as if a 100 million megaton nuclear bomb were to be detonated.
A collision of a comet into the earth would be a reasonably bad day. The earth would shake, the atmosphere would heat to about 600 degrees Fahrenheit, and the planet would burst into flames. All buildings