Is it feasible to think we could produce an atmosphere on Mars 'Alien' style, given the fact that mars has polar caps? What about 'air plants' ~ the sort you never have to water. Would they survive on Mars? Also what about Venus? Given that there are microbes that exist in the extreme conditions of immense pressure and hostile sulphur vents at the bottom of the ocean. Could we pollenate Venus with these and try to introduce life there?