A historic telescope is now very modern: the 200-inch (5.1 meters) Hale Telescope on Palomar Mountain in California has a web cam.

The Hale was the world's largest telescope for 45 years (1948–1993), and it still performs science. This morning, around 9 PST, engineers will lift off the top of the telescope and bring it down to the observing floor in order to aluminize the secondary mirror. Check it out. If you miss it, don't worry — the web cam will run 24/7, so you'll have plenty of chances to see the scope in action.