Here’s a cool idea:

Angel, a leading astronomer at the University of Arizona, is proposing an enormous liquid-mirror telescope on the moon that could be hundreds of times more sensitive than the Hubble Space Telescope.

Using a rotating dish of reflective liquid as its primary mirror, Angel’s telescope would the largest ever built, and would permit astronomers to study the oldest and most distant objects in the universe, including the very first stars.

One thing I don’t get, though. How would you point it? It doesn’t seem like it could be angled up very much out of local horizontal without both messing up the surface shape and requiring higher spin rates. That means that it’s only going to point at the area of the sky corresponding to the current local vertical at the lunar location (presumably they’d want to be on the far side to avoid light interference from the earth). And even then it would take a month to see the whole sky on a swathe, with no ability to go back and take a second look until twenty-eight days later. But if you had a bunch of them scattered all over the far side, you could have a pretty flexible system. This also means you’d have to have data relay satellites, either a constellation in lunar orbits, or a halo around L-2, if you’re going to be able to do earth-based astronomy with it.

As the article notes, this would probably require hand assembly to a large degree, which could provide a lot of motivation for lunar bases and lunar construction workers, and potentially even affordable, as long as you don’t let NASA get involved. It’s the kind of project that demands a lunar infrastructure, for communications as noted above, and habitats. It would be a great way (and perhaps incentive) to industrialize the moon. NSF should tender some bids, and see what the private sector comes up with.

[Via John Hood]