<span>Many planets are made of gas, and in different situations, the atmosphere can be destroyed.
The sun which is burnt measures atmosphere and in the same case planets can be in a good situation on galactic map and a great condition in the atmosphere as well as earth.
For example, the mass of an object can attract a smaller object causing gravity. The bigger the masses of a planet when it is in the right condition the more atmosphere it can attract if there is any floating on the planet. If it is big it will make a gravitational influence and gather more gases.</span>
Probably the animals and what the animals live in.
