One of the reasons Elon Musk proposes a Mars colony is that it would serve as a backup for Human Civilization, just in case the worst happens to Earth. The idea has caused some controversy from environmentalists who suggest that Musk regards the home planet of humanity as disposable. Better, they suggest, that we bend all efforts to preserving the Earth before gallivanting off to someplace else.

Robert Walker, writing for Science 2.0, is okay with the idea of a backup to Earth. However, he suggests that the moon is a better location. The reason he suggests this stems from the principle familiar with every computer user that the purpose of a backup is to restore the original if it should prove necessary.

What does a lunar based backup look like?

The first thing that needs to be protected from some planetary catastrophe on the moon would be the life that resides on Earth. A seed bank, similar to one that already exists in Norway, could be tucked away in one of the lava tubes that resides deep below the lunar surface. Likely some way would be found to preserve animal life as well, likely as frozen embryos and so on. The human colonists themselves, who would partly serve as caretakers for the backup system, would serve as the start of a restoration of Earth’s population should the human planet need restoration.

The other thing that will need backing up will be the sum total of knowledge, history, and culture of the human race.

Copies of the content of the Internet would be uploaded to a lunar based storage facility periodically. Copies of every book ever written would also be stored. 3D virtual reality images of culturally and historically significant places on Earth say the Pyramids of Giza, Angor Wat, and the Acropolis would also be stored away.

Restoring Earth

Suppose that some catastrophe were to wipe out all Life On Earth, say an asteroid impact, a thermonuclear exchange, or an environmental disaster. The lunar colonists will wait until the after-effects of such an event die down, even if it takes decades, and then go to work. New life would be seeded in appropriate locations.

Then animals would be “hatched” and released into the wild. Human beings, as a reverse of what many assume the future to be, would recolonize Earth, either restoring wrecked cities or building new communities. The process would likely take centuries

What about the Mars colony?

None of what was described above precludes settling Mars. One of the most tiresome debates in space policy circles is, go back to the moon or go to Mars. Every good undertaking, especially preserving and backing up the Earth, benefits from redundancy. Earth, moon, or Mars? Why choose?