Scientists at the University of Arizona's Steward Observatory Mirror Lab in Tucson have prepared the second 8.4-m mirror for the Large Binocular Telescope, scheduled for completion in 2004. They inspected and sorted tons of E 6 borosilicate glass from Ohara Glass Co. of Kanagawa, Japan, and hand-loaded more than 41,000 lb for the honeycomb mirror blank into the mold inside the furnace.

The binocular telescope, which will be located at Mount Graham International Observatory in Safford, Ariz., will produce images 25 times brighter and 10 times sharper than those from the Hubble Space Telescope. Acting as a nulling interferometer, the telescope will eliminate the light from nearby stars to resolve planets or planetary discs around them.