Comet
A comet is a small celestial object that orbits the Sun and is composed of ice, dust, and rocky debris. When a comet approaches the Sun, the heat causes the ice to vaporize and release gas and dust, forming a glowing coma or a tail that points away from the Sun due to solar wind.
Comets are often described as "dirty snowballs" because they consist of mostly water ice mixed with dust and other organic compounds. They originate from two regions of the solar system: the Kuiper Belt, which is located beyond Neptune's orbit, and the Oort Cloud, a far-reaching region beyond the Kuiper Belt.
Comets can have highly elliptical, elongated orbits that take them to the far reaches of the solar system and back. When a comet is far from the Sun, it is in a dormant state and is difficult to observe. However, as it approaches the Sun, the increased heat causes the ice to vaporize and form a glowing coma, which gives the comet its characteristic appearance.
The tail of a comet is formed when the solar wind pushes the released gas and dust away from the comet, creating a bright trail that points away from the Sun. This tail can be visible from Earth and can sometimes stretch for millions of kilometers.
Comets have been observed by humans for thousands of years and have often been associated with mythical and supernatural events. They have been studied extensively by astronomers, and their composition provides valuable insights into the early formation of the solar system.
Some famous comets include Halley's Comet, which has been observed since ancient times and returns to the inner solar system about every 76 years, and Comet Hale-Bopp, which made a highly visible appearance in 1997.