Meteors come from meteoroids. Meteoroids are small particles usually the size of a grain of sand that enter the atmosphere. Then as it is burning up, it is called a meteor. Meteors become visible when friction caused by air molecules slamming against the surface of the high-velocity particle. The friction cause the meteor to change to a color or colors. Most meteors burn up in the atmosphere at altitudes of 60 to 80 miles. They are mostly seen for only a period of a few seconds. Sometimes a large meteor won't burn up completely as it travels through the atmosphere. The remaining pieces that hit the earth are called meteorites.
