Nearly all asteroids are irregularly shaped, although a few of the largest are nearly spherical. They are often pitted or cratered . The surfaces of most asteroids are thought to be covered in dust. Comets are like dirty snowballs, consisting of rocks, dust and frozen gas. As they near the heat of the sun, the ice on their surface begins to melt. This forms a gas cloud that is stretched by solar winds to form their famous tail. Meteors, also known as shooting stars, are small pieces of rock and debris that have entered the Earth’s atmosphere. Most meteors are the size of a pea or smaller and completely burn up before reaching the surface. Occasionally, larger meteors strike the surface, and their remains are called meteorites. hope this helps !!!