Comets

Gravity, one of the four forces in creation also has effect on comets also. Comets are sometimes known as "dirty snowballs". The ice on these comets isn't just from water...it is also from frozen carbon dioxide.

When a substance turns from a solid to gas we say it has sublimated. The nucleus of a comet is is the dirt and ice and the coma of a comet is the atmosphere around it. There are particles being emitted from the sun and when these particles pushed away it causes a wind called, solar wind.

There are short period comets and long period comets. Short period comets take less than 200 years to orbit. Long period comets take more than 200 years. Scientists have found many comets, the shortest orbit is 3.3 years and some of the longest go over 5,000 years.