A comet is an approximately spherical body that can reach a diameter of about ten kilometers. It is made of ice and dust. Its name comes from the Greek coma which means “tail”. Indeed, when a “dirty snowball” approaches the Sun, some of its matter sublimates and the star develops a tail of dust several million kilometers long. This matter reflects the Sun’s light, which makes the body visible from the Earth, we then speak of comets.
Comet Neowise (C/2020 F3)