A new study shows energy output from 200,000 galaxies is half what it was billions of years ago. It's further evidence the universe is slowly declining. This undated NASA Hubble Space Telescope image shows the spiral galaxy NGC 1512 captured in all wavelengths from ultraviolet to infrared. Kevin Dietsch/UPI/Landov hide caption

itoggle caption Kevin Dietsch/UPI/Landov

The SpaceX Falcon 9 rocket and Dragon spacecraft break apart shortly after liftoff from the Cape Canaveral Air Force Station in Cape Canaveral, Fla., on June 28. SpaceX CEO Elon Musk said Monday the failure of a steel strut likely caused the rocket to explode. John Raoux/AP hide caption

itoggle caption John Raoux/AP

Harry Kroto, pictured in 1996, displays a model of the geodesic-shaped carbon molecules that he helped discover. Michael Scates/AP hide caption

itoggle caption Michael Scates/AP

The new spacecraft, called LightSail, is orbiting Earth. Future versions could travel to the moon and beyond. The Planetary Society hide caption

itoggle caption The Planetary Society

The Two-Way

Solar Sail Unfurls In Space

A nonprofit has successfully tested technology that could one day be used to explore the solar system on a budget.

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The view of the universe known as the Hubble Deep Field, presented in 1996, shows classical spiral and elliptical shaped galaxies, as well as a variety of other galaxy shapes. NASA/AP hide caption

itoggle caption NASA/AP

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

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