Food for thought # 3: planets and atmospheres

Due: Wednesday, 30 September 2020, 11:00 PM

Planets have a so-called escape velocity: if a particle (or body) is moving away at speed exceeding the escape velocity, the gravitational pull is not strong enough to withhold it. The escape velocity is given by where is the gravitational constant, is the mass of the planet to escape from, and is the distance of the particle/body from the center of the planet. Assume that particles at the top of an atmosphere follow the Maxwellian distribution. Discuss the existence of atmospheres around different kinds (size, mass, temperature) of planets keeping in mind that the particles collide exchanging energy and momentum.