1. Comets and Asteroids BY Travis Mazza & Mack Pekar

2. Comets Comets are small, fragile, irregularly shaped bodies composed of a mixture of non-volatile grains and frozen gases. Comets are small, fragile, irregularly shaped bodies composed of a mixture of non-volatile grains and frozen gases. They have highly elliptical orbits that bring them very close to the Sun and swing them deeply into space, often beyond the orbit of Pluto. They have highly elliptical orbits that bring them very close to the Sun and swing them deeply into space, often beyond the orbit of Pluto. As comets approach the Sun they develop enormous tails of luminous material that extend for millions of kilometers from the head, away from the Sun. As comets approach the Sun they develop enormous tails of luminous material that extend for millions of kilometers from the head, away from the Sun.

3. Cont. develop a surrounding cloud of diffuse material, called a coma, that usually grows in size and brightness as the comet approaches the Sun. Usually a small, bright nucleus (less than 10 km in diameter) is visible in the middle of the coma. The coma and the nucleus together constitute the head of the comet. When far from the Sun, the nucleus is very cold and its material is frozen solid within the nucleus. In this state comets are sometimes referred to as a "dirty iceberg" or "dirty snowball"

4. Cont. The evaporated molecules boil off and carry small solid particles with them, forming the comet's coma of gas and dust The evaporated molecules boil off and carry small solid particles with them, forming the comet's coma of gas and dust As the comet absorbs ultraviolet light, chemical processes release hydrogen, which escapes the comet's gravity, and forms a hydrogen envelope As the comet absorbs ultraviolet light, chemical processes release hydrogen, which escapes the comet's gravity, and forms a hydrogen envelope The tail of the comet stays away from the sun because of the solar winds of the sun blowing the tail away The tail of the comet stays away from the sun because of the solar winds of the sun blowing the tail away

5. Asteriods Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets Asteroids range in size from Ceres, which has a diameter of about 1000 km, down to the size of pebbles. Sixteen asteroids have a diameter of 240 km or greater Most, are found in the main belt that exists between the orbits of Mars and Jupiter

6. Cont. Asteroids are material left over from the formation of the solar system One theory suggests that they are the remains of a planet that was destroyed in a massive collision long ago Asteroids that are on a collision course with Earth are called meteoroids.

7. Work Cited http://encke.jpl.nasa.gov/index.html http://www.solarviews.com/ss.html