Ice planets form just like any other planet, matter and space dust clouds collide into one another and slowly form a planetoid. For a planet to fall into the category of an ice planet they must have extremely low surface temperatures which create their icy surface.

Ice planets have such a low temperatures due to their distance from a star. The planet would capture less of a stars energy due to the extreme distance from the energy source. An example of this is the dwarf planet Pluto, which is about 3.67 billion miles (Earth is 92.96 million miles). Due to this vast distance the dwarf planet receives an insignificant amount of energy to change the dwarf planets surface temperature.

Another reason for these extreme temperatures is that these planets have a little or no atmosphere, all the energy that the planet receives is quickly lost due the law of thermodynamics. An example of an insignificant atmosphere is the planet Mercury, a rock basin planet. Mercury is the closest planet to our sun, Mercury's temperature ranges from 465 to -184 Cecilius this is due to not having an atmosphere.