Editing Escape velocity (section)

=== From the surface of a body ===
An alternative expression for the escape velocity ''v''{{sub|e}} particularly useful at the surface on the body is:
: <math>v_\text{e} = \sqrt{2gr}</math>
where ''r'' is the [[distance]] between the center of the body and the point at which escape velocity is being calculated and ''g'' is the [[gravitational acceleration]] at that distance (i.e., the [[surface gravity]]).<ref>Bate, Mueller and White, p. 35</ref>

For a body with a spherically symmetric distribution of mass, the escape velocity ''v''{{sub|e}} from the surface is proportional to the radius assuming constant density, and proportional to the square root of the average density ''ρ''.
: <math>v_\text{e} = Kr\sqrt\rho</math>
where <math display="inline">K = \sqrt{\frac{8}{3} \pi G} \approx \mathrm{2.364\times 10^{-5} ~m^{1.5}{\cdot}kg^{-0.5}{\cdot}s^{-1}} </math>.

This escape velocity is relative to a non-rotating frame of reference, not relative to the moving surface of the planet or moon, as explained below.