kometid

Kometid, also known as comets, are small celestial bodies that orbit the Sun. They are composed of a nucleus, a coma, and a tail. The nucleus is typically a few kilometers in diameter and is made up of ice, dust, and rocky material. As a comet approaches the Sun, the heat causes the ice to sublimate, creating a glowing coma around the nucleus. The solar wind and radiation pressure then push the sublimated material away from the Sun, forming the comet's tail, which can stretch for millions of kilometers. Comets are often referred to as "dirty snowballs" due to their composition. They are believed to originate from the Oort Cloud or the Kuiper Belt, and their orbits can be highly elliptical, taking them far from the Sun for most of their orbit. Comets are of great interest to astronomers as they provide insights into the early solar system and the formation of planets. Some comets are periodic, returning to the inner solar system at regular intervals, while others are non-periodic and may only pass through the inner solar system once. Famous comets include Halley's Comet, which is visible from Earth every 76 years, and Comet NEOWISE, which became visible to the naked eye in 2020.