Comet Macholz: January 13, 2005. Comet nucleus tracked for 30 minutes with a Pentax 105 SHDF telescope and Canon 10D, Colorado Springs. In this view, the essential components of a comet are identified. The central nucleus of the comet is contained within the coma or atmosphere of the comet-the blue round cloud . The coma is very thin-- containing perhaps 100 particles per cubic centimeter as opposed to the earth atmosphere which is many millions of particles/cc. The smudge like extension pointing downward is the dust trail- a stream of dust that billows from the surface of the comet and trails the nucleus along the orbital trajectory of the comet. The long leftward tail is the ion tail of the comet which consists of ionic material swept from the nucleus by the solar magnetic field. The ion tail points directly away from the sun. The nucleus is 1-10 km in diameter and is sometimes referred to as a "dirty snowball-"it contains ices of water, methane,ammonia, and carbon dioxide with some organic compounds. Comets may have seeded the early earth with water and organic materials....