The University of Arizona

GMT4 Systematically checking the casting results

The fourth primary - center mirror of the Giant Magellen telescope began Friday, September 18, 2015.  The annealing process was completed December 21, 2015.  The mirror is now be prepared for the move to the handling ring and then the clean-out phase.
The mirror lab is the only place in the world you can experience this process.  Tours are available Monday through Friday.  Visit the Tour section of the website to purchase tickets.