In 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) impacted the Moon to determine the existence of water ice in permanently shadowed lunar craters. The upper stage of the satellite struck the Cabeus crater near the lunar south pole, creating a large plume. The satellite flew through that plume […]

The Navier-Stokes (continuum) equations fail to accurately represent a flow when the characteristic length scale for macroscopic gradients is on the same order as the mean free path of the molecules in a gas, and the Boltzmann equation is needed. It remove the continuum constraint and models the gas on […]