Expedition 47 Flight Engineer Tim Peake of the European Space Agency photographed rare, high-altitude noctilucent or “night shining” clouds from the International Space Station on May 29, 2016. Noctilucent clouds form between 76 to 85 kilometers (47 to 53 miles) above the Earth’s surface, near the boundary of the mesosphere and thermosphere. via NASA http://ift.tt/25HBcgZ

This 10.5-billion-year-old globular cluster, NGC 6496, is home to heavy-metal stars of a celestial kind! The stars comprising this spectacular spherical cluster are enriched with much higher proportions of metals — elements heavier than hydrogen and helium are curiously known as metals in astronomy — than stars found in similar clusters. via NASA http://ift.tt/1Zj64kh

New stars are the lifeblood of our galaxy, and there is enough material revealed by this Herschel infrared image to build stars for millions of years to come. via NASA http://ift.tt/1XgnuRn

An astronaut aboard the International Space Station used a powerful lens to photograph these three reefs in Australia’s Great Barrier Reef on Oct. 12, 2015. Reefs are easy to spot from space because the iridescent blues of shallow lagoons contrast sharply with the dark blues of deep water. via NASA http://ift.tt/1P1a2Iu

Former NASA astronaut Scott Kelly speaks about his historic mission aboard the International Space Station during an event at the United States Capitol Visitor Center, Wednesday, May 25, 2016, in Washington. via NASA http://ift.tt/1sfuKiW

Mars has bright polar caps of ice that are easily visible from telescopes on Earth. A seasonal cover of carbon-dioxide ice and snow is observed to advance and retreat over the poles during the Martian year. Scientists using radar data have found a record of the most recent Martian ice age recorded in the north polar ice cap. via NASA http://ift.tt/1sdb3bv

NASA’s OSIRIS-REx spacecraft is revealed after its protective cover is removed inside the Payload Hazardous Servicing Facility at Kennedy Space Center, on May 21, 2016. OSIRIS-REx, targeted for a Sept. 8 launch, will be the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study. via NASA http://ift.tt/1OWSkLu

On May 19, 2016, NASA’s IceBridge, an airborne survey of polar ice, crossed Greenland to fly central glacier flowlines in the east-central region of the country. This photo captures the fjord of Violin Glacier, with Nord Glacier at the upper left corner. This is IceBridge’s eighth spring campaign of science flights over Arctic sea and land. via NASA http://ift.tt/1s7jaq6

Cassini orbited in Saturn’s ring plane — around the planet’s equator — for most of 2015. via NASA http://ift.tt/1WcJKuB

CubeSats fly free after leaving the NanoRacks CubeSat Deployer on the International Space Station on May 17, 2016. Seen here are two Dove satellites. The satellites are part of a constellation designed, built and operated by Planet Labs Inc. to take images of Earth from space. via NASA http://ift.tt/27I2gi7