Some time ago, I posted an image of the Copernicus Crater for the Astronomy Picture of the Week. Now I stumbled upon an amazing painting by Marshal T. Savage depicting his vision of a future colony on the Moon. It’s the same Copernicus Crater, except it’s domed over and terraformed to create an ecosphere.
At first I thought that this was really cool, but it would be impossible to build such a gigantic structure. (The crater has a diameter of 93 kilometers!) However after giving it some thought I changed my mind. If it was built with a material strong enough like carbon nanotubes, it could in theory be built. While such as structure would be impossible on Earth, the Moon has a gravity six times lower, which means the structure would be six times lighter on the Moon. Also, the Moon has virtually no atmosphere. This means that the air inside the dome will create a difference of pressure between the inside and outside of the dome, which would help support the structure.
Though I doubt that this will be built in my lifetime, I would definitely want to live there if it happens! 🙂