http://www.rssboard.org/rss-specification 720 http://ecuip-xtf.lib.uchicago.edu/xtf/search?expand%3Dsubject;f1-subject%3DObservatory%20(ground-based);f2-associated-Lesson%3DGamma%20Ray%20Impact Results for your query: expand=subject;f1-subject=Observatory (ground-based);f2-associated-Lesson=Gamma Ray Impact Thu, 01 Jan 1970 12:00:00 GMT http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/Keck_telescope_mount/Keck_telescope_mount.dc.xml The twin Keck telescopes are located on Mauna Kea, a dormant volcano in Hawaii. The telescopes are the largest optical and infrared telescopes in the world with segmented mirrors that are made up of 36 hexagonal shaped mirrors each. Each 10-inch telescope stands eight stories tall and weighs 300 tons. http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/Keck_telescope_mount/Keck_telescope_mount.dc.xml Thu, 01 Jan 1970 12:00:00 GMT