Comets are celestial bodies that consist mainly of a nucleus made up of icy materials, such as water, dust, rock, and various organic compounds. They typically originate from the outer regions of the Solar System, particularly the Kuiper Belt and the Oort Cloud. Comets are characterized by their highly eccentric orbits, bringing them closer to the Sun at certain points in their trajectory.
The nucleus of a comet is relatively small, ranging from a few meters to tens of kilometers in diameter, and it is often referred to as the "dirty snowball" due to its composition. When a comet approaches the Sun, the heat causes the ice on its surface to vaporize, releasing gas and dust into space. This process creates a glowing coma, a cloud-like structure surrounding the nucleus, which may span several thousand kilometers in diameter.
As comets move closer to the Sun, the solar wind and radiation cause the released materials to form two distinct tails. The dust tail consists of tiny solid particles that reflect sunlight, while the plasma tail contains ionized gas that interacts with the solar wind. These tails can extend for millions of kilometers in the direction opposite to the Sun.
Comets are often observable from Earth as they approach the inner Solar System, illuminating the night sky and captivating observers. Throughout history, comets have been considered as omens or mystical phenomena by various cultures. Their study provides important insights into the early Solar System's formation and evolution, as well as the composition of distant bodies in the cosmos.
