3* Water also appears to be present on the moon[0] 4* Is that enough? We don't know, we've yet to do any centrifuge habitat experiments with small mammals 5*

3* Water also appears to be present on the moon[0] 4* Is that enough? We don't know, we've yet to do any centrifuge habitat experiments with small mammals 5* oxygen is so common, CO2 has the advantage of being gasseous, but silicates, aluminum and iron ores are the rocks you can't throw a rock without hitting and has the advantage that you only need to process a millionth the volume to get an equivalent number of moles to martian CO2. [0]https://en.wikipedia.org/wiki/Lunar_water https://en.wikipedia.org/wiki/Lunar_water