Not for the first time, actually. We started shooting images of the moon with Hubble circa 1999, mostly to see if we could. Hubble was designed to look at stuff that’s faint and far away and doesn’t move much over time. The moon is really close, extremely bright (by Hubble standards), and moves very fast compared to Hubble’s speed (17,000 mph, more or less) and the relative stillness of the more distant objects Hubble was designed to study. So a science team tried a quick experiment to see if it was possible to get a decent shot of the moon with Hubble, and it was.

A couple of years ago, Hubble was used to look for oxygen on the moon.

And geologists have also been using Hubble to map minerals on and below the lunar surface.

Space scientists are keen to map the concentration of the titanium-dioxide-rich mineral ilmenite on the moon’s surface, says Jim Garvin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Oxygen production from TiO2-enhanced lunar soils could potentially make breathable oxygen and even oxidiser for rocket fuel.”

UV images of the lunar surface show patterns that correlate with the concentration of TiO2 measured in lunar samples collected by the Apollo missions, and so a map of the UV variations can be used to create a map of TiO2 abundance. However, Earth’s atmosphere interferes with UV readings, so the team used Hubble to take UV images of a small area of the lunar surface that included the landing sites of the Apollo 15 and 17 spacecraft.

The point of this whole exercise is to figure out whether and where it might be possible to build a somewhat self-sustaining base on the moon. Astronauts, scientists and whoever else ends up living there will need to be able to “live off the land” as much as possible. And if there are enough minerals of the right types and quantities, it might be possible to assemble launch vehicles on the moon, gas ’em up there and send them on their way to Mars.

Which would be very cool.

It’s also worth pointing out that that telescope wasn’t designed to do any of this stuff. Exploring the moon with the Hubble Space Telescope in preparation for eventual manned missions to Mars is very much a bonus.