1. Comets are frozen leftovers from the formation of the solar system composed of dust, rock and ices.
2. Oort Cloud
3. Comet tails get longer and more impressive as the comet gets closer to our Sun.
4. A meteor shower occurs when the Earth passes through the trail of debris left by a comet or asteroid. /OR/ Meteors are bits of rocks and ice ejected from comets as they move in their orbits about the sun.
I have no idea to answer the ASTEROID Sorry but the following question will help.