Astronomer Chris Impey examines the possibilities of the universe in his new book Beyond. "I like the idea that the universe — the boundless possibility of 20 billion habitable worlds — has led to things that we can barely imagine," he says. In the 1970s, NASA Ames conducted several space colony studies, commissioning renderings of the giant spacecraft which could house entire cities. Rick Guidice/NASA Ames Research Center hide caption

itoggle caption Rick Guidice/NASA Ames Research Center

An image of the galaxy EGS-zs8-1, which set a new distance record after researchers determined it was more than 13 billion light-years away. NASA, ESA, P. Oesch, and I. Momcheva, and the 3D-HST and HUDF09/XDF teams hide caption

itoggle caption NASA, ESA, P. Oesch, and I. Momcheva, and the 3D-HST and HUDF09/XDF teams

This visualisation of the 3-D structure of the Pillars of Creation is based on new observations of the object using the MUSE instrument on ESO's Very Large Telescope in Chile. The pillars actually consist of several distinct pieces on either side of the star cluster NGC 6611. In this illustration, the relative distance between the pillars along the line of sight is not to scale. ESO/M. Kornmesser hide caption

itoggle caption ESO/M. Kornmesser

This image of a "red spot" on Mercury, which is thought to be the result of a volcanic explosion, was sent to Earth by the Messenger probe in 2011. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington hide caption

itoggle caption NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

An artist's rendition of the HD 7924 planetary system — just 54 light-years away from Earth — shows newly discovered exoplanets c and d, which join Planet b. Karen Termaura, BJ Fulton/UH IfA hide caption

itoggle caption Karen Termaura, BJ Fulton/UH IfA

A Russian launch vehicle carrying the Progress M-27M cargo ship lifts off from the Baikonur cosmodrome in Kazakhstan on Tuesday. Fears mounted Wednesday that the unmanned cargo capsule was lost and may plunge back to Earth as ground control failed to gain control of the orbiting ship for a second day in a row. Roscosmos /EPA /Landov hide caption

itoggle caption Roscosmos /EPA /Landov

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

Native Hawaiians dance in honor of Mauna Kea at the base of Pu'u Huluhulu on the Big Island. Molly Solomon/NPR hide caption

itoggle caption Molly Solomon/NPR

You won't be able to use a robot lawn mower within 55 miles of the Robert C. Byrd Green Bank Telescope in Green Bank, W.Va., if the National Radio Astronomy Observatory has its way. Patrick Semansky/AP hide caption

itoggle caption Patrick Semansky/AP