All About Comets

            
             The picture of a comet is a spectacular object, with a brilliant head and a .
             long tail, streaming across the heavens. Observations of the comet of 1577 by .
             Tycho Brahe demonstrated that comets were more distant than the moon. Some .
             comets are spectacular objects, but definitely the greatest numbers are not very .
             bright, and many do not develop tails. Comets are classed with asteroids, .
             satellites of the planets, and meteoroids. Comets provide a source of .
             information on how the solar system originated, and also provide opportunity to study .
             matter under abnormally physical conditions. The distinguishing feature of a .
             comet is its ability to release large amounts of dust and gas when its nucleus .
             is heated by solar radiation when close to the sun. The material released is .
             lost to the comet, and therefore the lifetimes of comets must be limited. .
             The majority of comets observed today is faint, and have no tail and little .
             coma. While in orbit, comets cover a wide range, moving about the sun in .
             orbits impossible to tell apart from those of minor planets, while others follow .
             paths similar to the earth's orbit plane. Many comets have elongated orbits, .
             which draw back to tens of thousands of astronomical units from the sun. The .
             comets actually observed are just a tiny part of the whole number of other .
             objects in the solar system.
             DISCOVERIES.
             There have been many discoveries of comets, recent, and from past years. .
             Professional astronomers have found most new comets reported in recent years, .
             while others are discovered by accident. When a new comet is discovered, the .
             most important need is to be able to make additional observations. Often the .
             motion of comets is slow and uniform that observations every within a few .
             nights can provide enough information to assume its position for the next .
             observation session. Sometimes, if the comet is fainter or if observations are to be .
             obtained without the proper telescope, more exact knowledge of the position .