you might be talking about Pluto, but its not considered a planet anymore.
Usually comets are icy as that is why you see the icy trail, but asteroids can be icy too.
Basically, Earth is a planet, the Sun is a star, and a comet is an icy small body of ice.
Comets are often referred to as "dirty snowballs" or "icy mudballs" due to their icy composition mixed with dust, rock, and organic compounds.
Uranus and Neptune are the Ice Giants. Mars also has ice as too does Mercury and Earth.
Asteroids orbit the Sun between the orbits of the planet Mars and the planet Jupiter. Comets orbit the Sun on very elliptical orbits, originating from the Kuiper belt beyond the orbit of Neptune or the Oort cloud at the edges of the solar system. Comets are also usually (but not always) icy bodies that give of gas and dust (a tail) as they approach and get heated by the Sun. Meteorites are bodies that were Asteroids or Comets that have hit the planet Earth and landed on the surface.
The vast disk of icy comets near Neptune's orbit is called the Kuiper Belt. It is a region of the outer Solar System that contains numerous small icy bodies and serves as a source of short-period comets.
dirty snowballs or "icy mudballs
Comets
comets.
They have to orbit the sun or orbit a planet. This means they are if they are in the Galaxy.
Yes, comets have cores, also known as nuclei, which are typically made up of ice, rock, and organic compounds. The icy nucleus is the solid center of a comet that remains intact as it travels through space, with a coma and tail forming as the comet approaches the Sun.
They are called comets.