Rocks that range in size from a boulder to a grain of sand, are called meteoroids. They are composed of a number of different substances including; ice and iron. Meteoroids travel at very fast speeds in orbit around the sun. When that meteoroid or other interplanetary debris passes through our atmosphere, it burns up and creates a flash of light. This is commonly referred to as a meteor or "shooting star," and they are clearly visible from Earth under the ideal conditions. If any portion of that meteoroid lands on Earth, it is called a meteorite. This is also applicable to asteroids and comets. Meteorites are comprised of many different elements and if large enough, are capable of affecting our landscape. Asteroids are large rocks (remnants