It has been to believe that comets are masses of tiny solid particles held together loosely by gravitation. But this theory does not fit all the observed f

acts. Another theory suggest that comets are formed in cold outer space from the interstellar dust particles consisting of such compounds as methane, ammonia, and water, which probably exist as icy particles in outer space. They believe that 70 to 80 per cent of the mass of a comet form those icy particles. The other 20 or 30 per cent is formed from the interstellar dust into rocky and metallic materials such as found in meteorites. This rocky and metallic materials are found in meteorites. This rocky material is imbedded as dust and chunks in the icy material.

Comets travel around the sun in egg-like paths called ellipses. The time it takes a comet to make a complete orbit is called its period. Some comets travel in such long orbits that they are near the sun only once in t

Some common words found in the essay are:
, Edmund Halley, Europe Christian, halley's comet, metallic materials found, rocky metallic materials, materials found meteorites, interstellar dust, found meteorites rocky, materials found, tail bright, comet 1910, meteorites rocky, rocky metallic, metallic materials, found meteorites, miles diameter,
Approximate Word count = 531
Approximate Pages = 2 (250 words per page double spaced)