Steward Observatory Mirror Lab celebrated its 30th anniversary last year, but it’s a campus facility that sees about 2,000 visitors throughout the year, according to Cathi Duncan, the lab’s tour coordinator.

The Arizona Daily Wildcat went on a tour to see how this cornerstone of the UA’s research world helps astronomers and observatories around the world capture the light of the universe.

Visitors can see the progress of lab’s current projects, the Large Binocular Telescope and the Giant Magellan Telescope, through the three stages of mirror construction.

Casting is the first stage where molten borosilicate glass is roughly shaped into a honeycomb structure. The next step is grinding. Glass is chipped off with diamond bits until the mirror reaches its final shape. Finally, the mirror’s surface is polished down to the nanometer scale. Each stage of production is automated with technicians overseeing the process.

Each 8.4-meter mirror takes about five years to complete from casting to polishing. With its production schedule, the lab completes one mirror per year.

Tours are held from Tuesday to Friday at 1 p.m. and 3 p.m. and last 90 minutes. They cost $15 for adults, $8 for students, and groups are available.