Could we terraform the Moon?

Tamsin Bell asked planetary scientist David Rothery from the Open University to weigh in on this question from Chad.

Is it possible to terraform the Moon so humans could live there long term?

塔姆——我们问我们的追随者在论坛上they thought. User, diverjohn points out that the Moon is relatively close to Earth and suggest living in underground spaces would be possible. We could even use solar panels on the Moon’s surface to supply our electricity.

I spoke to Planetary Geoscientist David Rothery from the Open University…

David - Terraforming is usually understood to mean modifying the atmosphere, and hence also the temperature of a body to give it an environment where we could live. So in terms of us going to live in the open on the Moon, the answer is no. Because the Moon’s gravity is too weak to hang onto relatively light molecules such as water vapour, oxygen, and nitrogen in the long term.

Even supposing you found a way to liberate enough of those gases at the Moon’s surface to give it a breathable atmosphere, you’d have to continually replenish it as it leaked away to space.

Tamsin - So like all ‘bad first date’ restaurants on Earth, restaurants on the Moon would have no atmosphere…

David - It’s not just the Moon’s weak gravity that’s the problem, the Moon has no magnetic field to deflect the solar wind so this would always be eroding the top of the atmosphere.

The closest we might one day come to to a terraformed environment on the Moon might be inside a large transparent and leak proof dome. Fill this with the right mix of oxygen, carbon dioxide, water vapour, and nitrogen to more or less match the Earth’s atmosphere, and you could probably arrange for the average temperature inside the dome to be comfortable for humans, despite the nights lasting for two weeks. You could probably grow crops there too after a lot of work on the soil to get its structure and the microorganisms right.

Tamsin - If we did decide to move to the moon, we certainly would need to planet …

David - The biggest obstacle to humans living on the moon, or indeed anywhere in space, is the cost of transporting whatever resources you need from the Earth. Things would be so much easier and cheaper if we could get most of what we need at our destination rather than taking it with us.

We know there’s water in the form of ice inside the shadowed craters near the Moon’s poles. There’s plenty of oxygen that you could liberate at a large energy cost from lunar rocks. Carbon and nitrogen might not be so easy to come by though so we might need to depend on the Earth for quite a while.

Tamsin - Thanks for bringing us back down to Earth, David.

Next time we’ll be sticking to this one from Tom in Australia: Why is Blu Tac sticky?