How do you make a telescope mirror 8.4 meters in diameter? Well, it’s easy — you just take 24 metric tons of glass, put it in a big form, spin it while you’re melting the glass….
Oh, alright — there’s nothing easy about it! But people are going to the effort in order to build the Large Synoptic Survey Telescope (LSST), a leviathan designed to record the whole night sky every three days from the Chilean Andes. Unlike most large astronomical telescopes, the LSST was designed to have a very large field of view — the idea being to help with tracking near-Earth asteroids and catch supernovae explosions.
This week’s video comes courtesy of New Scientist magazine, explaining the telescope’s history (to date), and a tantalizing bit of how it’s being built:
The mirror is now in the middle of a three month cool-down after being melted; hopefully we’ll get to see some video of the melt / cooldown process in the not too distant future. Of course, since the source of the video is a magazine, there’s also lots of good reading material in the video’s accompanying article here.