Comets are small celestial bodies composed of ice, dust, rock, and other volatile compounds. They orbit the Sun in elliptical or elongated trajectories. As a comet approaches the Sun, the frozen material on its surface heats up, begins to vaporize, and forms a luminous coma (a kind of atmosphere) around the comet’s nucleus.
The nucleus of a comet is essentially a solid conglomerate of ice, dust, and rock. As the comet approaches the Sun, the coma is created by the heated gases released from the nucleus. These gases form a glowing veil around the nucleus. Under the influence of sunlight and the solar wind, the comet’s tail is often visible.
The comet’s tail consists of gases and tiny dust particles blown away from the Sun by the radiation pressure and solar wind. There are two main types of comet tails: the gas or ion tail, typically blueish and composed of ionized gases, and the dust tail, made up of small, reflective dust particles, usually appearing whitish.
Comets often originate from the outer regions of the solar system, beyond the orbit of Neptune. As they approach the Sun, they may become visible in the sky through telescopes or even with the naked eye. Some comets have a periodic orbit, recurring regularly near the Sun, while others are one-time visitors. Comets are considered “cosmic time capsules” as they may contain information about the composition and conditions of the early days of the solar system.
12P/Pons-Brooks
C/2017 K2 (PANSTARRS)
C/2021 A1 (LEONARD)
C/2022 E3 (ZTF)
