Back to Math And Terraforming The behavior of an atmosphere is very important for terraforming. There are a few formulas that can calculate if a planet is suitable to support an atmosphere and under what conditions. You can determine average gas speed with the formula [1]: The second thing we need to consider is escape velocity, to see if the gas will escape or not the planet. The formula, adapted for our simulation and our measure units, is: Here, Ev is the escape velocity in km/s, mass is the planet's mass (Earth's mass = 1) and diam is the diameter, in thousands km.