What sets a dwarf planet apart from an asteroid or comet?
Form sets them apart.
A dwarf planet is usually circular or oval shaped while asteroids and comets have irregular forms. Also, comets are made out of mostly ice, asteroids are that what is left from the creation of planets and dwarf planets are planets but just smaller in size. Hope it helps it's my first time I answer somewhere.
There is a well defined definition for a dwarf planet.
A dwarf planet has to meet two criteria:
- It must be orbiting the Sun
- It must be massive enough fro gravity to make it roughly spherical
Asteroids are typically small rocky objects. They meet the first criteria, but usually not the second as they are too small. One asteroid Ceres is now classified as a dwarf planet.
Comets are icy bodies which tend to have very eccentric orbits. They again meet the first criterion, but are two small to meet the second.