20th and 21st Centuries Developments Posted on 8th November 20248th November 2024 By Stephen Drury No Comments on 20th and 21st Centuries Developments Long exposure wide angle image of the Hale Telescope inside the Palomar Mountain Observatory in southern California. 200” mirror reflector 2.5 meter mirror optical 6.5 meter beryllium gold coated infrared Share on X (Opens in new window) X Share on Facebook (Opens in new window) Facebook Like this:Like Loading... Uncategorized