What is the smallest planet where an astronaut could accidentally escape gravity?

Leon Rozing


In this article, it is evaluated what the required dimensions of a small object in space (such as a small planet, a moon or an asteroid) should be in order to have a gravitational pull that is just strong enough to not let humans escape it by running and jumping. By evaluating the escape velocity, it is found that a mass-to-radius ratio of 5.8x1010 kgm-1 will prevent regular astronauts from escaping, and a ratio of 1.15x1012 kg m-1 will prevent even the fastest human alive from escaping the gravitational pull. Objects in our solar system that are near these ratios are Leda, 433 Eros and S/2003 (130) 1.


Physics; Gravity/orbits; Astrophysics; Escape velocity

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