By Matt Lever
Nothing.
“But… but Mars has CO2 in the atmosphere, soil, and sunlight!” I hear you reply.
Mars has an atmosphere, sure. But it’s atmosphere is so incredibly tenuous in comparison to Earth’s that it may as well not be there at all, at least so far as a respirating organism is concerned. Partially thanks to this, it is also perishingly cold, particularly at night. Siberia would seem like Tunisia in comparison.
And yes, Mars has soil. It’s dead soil, though. Not only is it not going to be nutritious to a burgeoning plant baby, but it would also be toxic. To say nothing of how frigid and dry it is.
And it may well receive sunlight, but only about half as much as we get on Earth. Contrariwise, Mars lacks an effective magnetosphere, so much more radiation gets down to the surface. So even if that first shoot somehow forced its way out of the toxic, perishingly cold, infertile soil, and somehow managed to suck out some CO2 from that tenuous, dry atmosphere, it would be starved of light and irradiated.
And then blown away by ferocious winds and torn apart by sandstorms.
Mars is one of the most habitable planets in the solar system besides Earth. But don’t let that fool you — that says more about the rest of the planets in the solar system than it does about Mars. As it stands now, planting a tree there would just be a seed funeral.