Characteristics of comets
In addition, comets can carry the names of the people who discovered them, e.g., comet Halley, comet Machholz, comet shoemaker–levy 9 comet or Mac Note.
Movement and spatial distribution
All comets are members of the Solar system. They, like the planets, are subject to the laws of gravity, but move very peculiar. All the planets revolve around the Sun in one direction (which is referred to as “direct” as opposed to “reverse”) on nearly circular orbits that lie roughly in one plane (the Ecliptic), while comets move in both forward and reverse directions on highly elongated (eccentric) orbits, inclined at different angles to the Ecliptic. It is the nature of motion immediately gives the comet.
Long-period comets (orbital period greater than 200 years) come from regions located thousands of times further than the most remote planets, and their orbits are tilted at all angles. Short-period comets (period less than 200 years) come from the region of the outer planets, moving in the forward direction for orbits lying close to the Ecliptic. Away from the Sun, comets usually do not have “tails”, but sometimes have a barely visible “to”, surrounding the core; together they are called the “head” of the comet. Approaching the Sun the head is increased and there is a tail.
Types of tails comets researched by the Russian astronomer F. A. Bredikhin. In the late nineteenth century from razdelyvanie comets into three types:
Type I tails of comets straight and directed away from the Sun along the radius vector; type II tails wide, curved; type III tails directed along the comet’s orbit. Such tails are narrow.
Quite rare comet tails are directed towards the Sun. This so-called anomalous tails. Under the influence of the solar wind and dust particles are discarded in the direction opposite the Sun, forming the dust tail of the comet. The dust tail of a comet usually has a yellowish color and the light reflected from the Sun light.
Visible white dust and blue plasma tails of comets
Plasma tail of a comet is usually a bluish color. Plasma tail of a comet is formed from gas that is electrified under the action of ultraviolet radiation from the Sun – plasma.