As always, whenever we have something like this people get overexcited for terraforming Mars. Or even living on Mars. First, terraforming. This is such a monum

As always, whenever we have something like this people get overexcited for terraforming Mars. Or even living on Mars. First, terraforming. This is such a monumentally massive task that it is almost beyond comprehension. The distribution of molecular velocities in a fluid is a Boltzmann distribution. The average of that is the temperature. Some molecules go very fast. In a liquid this allows them to overcome surface tension and gravity and become a gas. This is evaporation in water. In an atmosphere, a certain portion of the molecules are fast enough to escape the atmosphere and to be lost to space. This is called the Jeans escape energy. The Earth's atmosphere loses about a million tons of gas every year. And that's fine because the atmosphere is many orders of magnitude more massive than this. Mars has lower atmosphere and no protective magnetosphere from solar winds. This means proportionally more mass loss. The atmosphere would have to be so massive that you can afford to lose possibly millions of tons of it every year. You can calculate how much energy that requires and it is massive. So this brings us to creating oxygen for habitats. This is a way more solvable problem. Mars still has all the suual negatives: 1. A weak atmosphere, which is actually worse than no atmosphere, because it covers all your stuff in dust. Some dust storms last months; 2. The ground is toxic (eg perchlorates). There'd be no growing food like in The martian; 3. Low gravity; 4. No protection from solar and cosmic radiation because of no magnetosphere and (almost) no atmosphere. So you can calculate the energy cost per gram of oxygen this produces and work out how much you'd need to create for whatever use (eg breatheable air, making water, making rocket fuel) and then work out how you'd get that energy. Solar is the likely candidate. I think you'll find the required footprint is massive. Oh and cosmic radiation is important for life on Earth. Why? Cosmic rays are constantly hitting nitrogen in the atmosphere. At a predictable rate, some of these nitrogen atoms (7 protons, 7 neutrons) such that a proton becomes a neutron. 6 protons and 8 neutrons is Carbon-14. That's literally how we do carbon dating (because C14 is radioactive).