A comet is a small celestial body made up of ice, dust, and various gases. They typically have a relatively small solid nucleus, around which a bright and large coma (a cloud of gas and dust) forms as the comet gets closer to the Sun. The coma can be several hundred thousand kilometers across. As the nucleus warms, gas and dust are released and form a bright tail that always points away from the Sun.
Comets are considered to be “dirty snowballs” because they are made mostly of water ice, but also contain dust, carbon dioxide, nitrogen, and other volatile materials. They are believed to have formed in the colder regions of the solar system, such as the Oort Cloud and the Kuiper Belt, and are thought to be leftover debris from the formation of the solar system.
When a comet’s orbit brings it close to the Sun, the heat causes the ices in the nucleus to sublimate (go directly from a solid to a gas), and the gas and dust from the coma and tail form. This is why comets are often visible in the night sky as they approach the Sun. The most famous comet is Halley’s comet, which has a regular orbit and is visible from Earth every 75-76 years.
Comets have been known since ancient times and have been observed by civilizations all over the world. They have also been studied by astronomers and scientists for centuries, and many comets have been visited by spacecraft to study their composition and behavior in more detail.
Overall, comets are fascinating objects that can provide insight into the formation and early history of the solar system and still are a subject of research and study by astronomers and scientists.
Some examples of Comets:
- Halley’s Comet [ This is the most well know comet I think, haha ]
- Comet Hale–Bopp
- Comet ISON
- Comet Shoemaker–Levy 9
- Comet Encke