Comets were discovered by danish astronomer tycho brahe in 1577.Haleys comet was named after comond halley.Isaac newton showed that a comets movements are much like the same laws that control the planets orbits.

Comets are usually about 9.2 million miles from earth.Sometimes comets get in the way of another comet and they will collide.

Comets have an icy body. Therefore they are super cold.The atmosphere around a comet is a gas cloud.

There are many different kinds of comets.This is a list of them:Main belt comets, centaurs, krentz sungrazers, short period comets, and great comets.

The physical characteristics of comets are that they have an icy body that releases gas or dust.

No life on comets could not exist because comets are made of ice, dust, and little pieces of rocks; therefore it is impossible to go to a comet.

Asteroids were made when something hits a planet or moon and a piece of rock chips off.Asteroids are known to be grouped together in an asteroid belt.

The main asteroid belt is about 5 km from the earth.

Asteroids are made of rocky chunks of matter in orbit around the sun.

Asteroids are varied in their composition.Most are made of rock, but some are composed of metals and other materials.

Asteroids range in size and are just rocks.

Life could not exist on an asteroid because it is just a giant rock.

Every asteroid is different because of the different sizes,orbits, and compositions; But the average asteroid in the asteroid belt is about -150C.Around an asteroid is usually rocks, cold ice, dust, and other minerals.

They have only found 7 meteoroids that have hit earth in history. All of the 7 that hit earth were large impact.

Most meteoroids move close to the earth, however, only few of them hit earth. The rest of them just pass by.

Meteoroids are 3.5x more dense then an earth rockTheir size is at least the size of speck of dust but smaller then an asteroid.Meteoroids are made of a small piece of dust, rock, ice, or metal.

Meteoroids are mainly iron.Meteoroids temperature depends on weather in sunlight or moonlight.Move at light speed.

No life could not exist because a meteoroid is just a fast moving space rock and will get to cold and to hot.