Nebula
It is a cosmic body, formed from a cloud of dust and gases.
A comet has a tail composed of gases and dust. As a comet travels through space, it heats up, causing the gases and dust to vaporize and form a glowing tail that points away from the Sun due to solar wind.
my planet
The planet that fits this description is Pluto. It is considered a dwarf planet and is composed of rock, water ice, and frozen gases like methane and nitrogen, giving it a "dirty snowball" appearance.
Jupiter
rock dust water
none
planet 78 is a made up planet by a boy. it has green dust on the ground and is very big
A comet is made up of icy dust particles and frozen gases such as water, carbon dioxide, methane, and ammonia. When a comet comes closer to the sun, these ices can vaporize and form a glowing coma and a tail.
Milky Way Galaxy
Saturn.
It has faint rings which are made of dust.