Comets are small celestial bodies.
They are nebulous in color, and the comets in the Milky Way revolve around the Sun.
Over 6340 comets exist in the known Milky Way.
Like other celestial bodies, we could see comets in the sky every year, still with the naked eye.
Their tail is formed due to the fact that they are approaching the Sun, and the tail is actually formed by the remains of the comet.
We can say that a comet looks like a star, because the comet also has a rather strong core, and its tail is made of cosmic dust and gases from the comet.
There are several types of comets in the Milky Way:
Periodic short comets from the Kuiper Belt;
Long periodic comets that go beyond the dwarf planet Pluto;
Non-periodic comets that are mostly from the Oort Cloud.
Comets can die from lack of fuel, core defragmentation, or impact with another celestial body.