The Hooker 100-inch reflecting telescope at the Mount Wilson Observatory, just outside Los Angeles. Edwin Hubble's chair, on an elevating platform, is visible at left. A view from this scope first told Hubble our galaxy isn't the only one. Courtesy of The Observatories of the Carnegie Institution for Science Collection at the Huntington Library, San Marino, Calif. hide caption

itoggle caption Courtesy of The Observatories of the Carnegie Institution for Science Collection at the Huntington Library, San Marino, Calif.

A giant cluster of about 3,000 stars called Westerlund 2. The cluster resides in a raucous stellar breeding ground known as Gum 29, located 20,000 light-years away in the constellation Carina. NASA, ESA, STScI/AURA hide caption

itoggle caption NASA, ESA, STScI/AURA

The Horsehead Nebula, as seen with infrared light, shows clouds surrounding it have already dissipated. The Horsehead formation has about 5 million years left before it, too, disintegrates. NASA/ESA hide caption

itoggle caption NASA/ESA

An image taken with the NASA/ESA Hubble Space Telescope of the galaxy cluster SDSS J1038+4849 shows that it seems to be smiling. The space agency says it's the result of a symmetrical alignment of the galaxy cluster and the telescope — along with a powerful gravity field that can bend light. NASA & ESA hide caption

itoggle caption NASA & ESA

Larkin Carey, an optical engineer with Ball Aerospace, examines two test mirror segments designed for the James Webb Space Telescope. The mirror for the scope is extremely powerful, but heavy and pricey. NASA hide caption

itoggle caption NASA
NASA/ESA/M. Buie (Southwest Research Institute)

Artist concept of New Horizons spacecraft. The Hubble Space Telescope is being pressed into service to help scientists look for a post-Pluto target for the space probe. Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute hide caption

itoggle caption Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute