On July 20, 1976, at 8:12 a.m. EDT, NASA received the signal that the Viking Lander 1 successfully reached the Martian surface. This major milestone represented the first time the United States successfully landed a vehicle on the surface of Mars, collecting an overwhelming amount of data that would soon be used in future NASA missions. via NASA http://ift.tt/2a90sYR

Sea ice across the Arctic Ocean is shrinking to below-average levels this summer. NASA’s Operation IceBridge, an airborne survey of polar ice, just completed its first flights studying the aquamarine pools of melt water on the ice surface that may be accelerating the overall sea ice retreat. via NASA http://ift.tt/29RigKX

Saturn’s main rings, along with its and moons, are much brighter than most stars. via NASA http://ift.tt/29IeWgg

This image, taken by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), shows a starburst galaxy named MCG+07-33-027. This galaxy lies some 300 million light-years away from us, and is currently experiencing an extraordinarily high rate of star formation — a starburst. via NASA http://ift.tt/29JrCFz

Expedition 48 Commander Jeff Williams of NASA captured photographs of western Cuba and the Gulf of Batabanó as the International Space Station flew overhead. Williams shared this composite image on social media, writing, “Wow! Look at how the navy blue contrasts with the aqua, Gulf of Batabano Cuba.” via NASA http://ift.tt/29SEGs9

In this view looking up from the floor of the Vehicle Assembly Building at NASA’s Kennedy Space Center, four levels of new work platforms are now installed on the north and south sides of High Bay 3. The G-level work platforms are the fourth of 10 levels that will surround and provide access to the Space Launch System rocket and Orion spacecraft. via NASA http://ift.tt/29ypmhH

Crew members on the International Space Station re-installed the first 3D printer in orbit, during the week of June 27, 2016, to continue research on the developing technology and how it can be used in space. NASA astronaut Jeff Williams installed the printer in the Microgravity Science Glovebox to begin another round of sample builds. via NASA http://ift.tt/29ESS9C

Around local midnight time on April 8, 2015, astronauts aboard the International Space Station took this photograph of Paris, often referred to as the “City of Light.” The pattern of the street grid dominates at night, providing a completely different set of visual features from those visible during the day. via NASA http://ift.tt/29rwZuE

This image of dark dunes on Mars was taken on Feb. 6, 2016, by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter. These dunes are influenced by local topography. The shape and orientation of dunes can usually tell us about wind direction, but in this image, the dune-forms are very complex, so it’s difficult to know the wind direction. via NASA http://ift.tt/29nBK4S

The Soyuz MS-01 spacecraft launches from the Baikonur Cosmodrome with Expedition 48. via NASA http://ift.tt/29lNbcQ