Alluvial fans are gently-sloping wedges of sediments deposited by flowing water. Some of the best-preserved alluvial fans on Mars are in Saheki Crater, an area that has been imaged many times previously. via NASA http://ift.tt/1UKgLwX

A United Launch Alliance Atlas V rocket carrying Orbital ATK’s Cygnus spacecraft on a resupply mission to the International Space Station lifts off from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida at 11:05 p.m. EDT on March 22, 2016. via NASA http://ift.tt/1q1rw1q

The Cygnus spacecraft sits on top of an Atlas V rocket ready for launch to the International Space Station on March 22, 2016. via NASA http://ift.tt/1RhQDns

A new map of Mars’ gravity is the most detailed to date, providing a revealing glimpse into the planet’s hidden interior. The map was derived using Doppler and range tracking data collected by NASA’s Deep Space Network from three NASA spacecraft in orbit around Mars: Mars Global Surveyor, Mars Odyssey, and the Mars Reconnaissance Orbiter. via NASA http://ift.tt/1S0UaX5

A Soyuz rocket lifts off from rom the Baikonur Cosmodrome in Kazakhstan on March 19, (March 18 U.S. time) carrying Expedition 47 to the International Space Station. via NASA http://ift.tt/1pRW2L3

The gantry arms close around the Soyuz TMA-20M spacecraft to secure the rocket, as seen in this long exposure photograph taken on Wednesday, March 16, 2016 at launch pad 1 at the Baikonur Cosmodrome in Kazakhstan. Launch of the Expedition 47 crew is scheduled for 5:26 p.m. EDT Friday, March 18. via NASA http://ift.tt/1SYozdh

This image of haze layers above Pluto’s limb was taken by the Ralph/Multispectral Visible Imaging Camera (MVIC) on NASA’s New Horizons spacecraft. About 20 haze layers are seen; the layers have been found to typically extend horizontally over hundreds of kilometers, but are not strictly parallel to the surface. via NASA http://ift.tt/1MpKPpM

On March 16, 1966, command pilot Neil Armstrong and pilot David Scott successfully docked their Gemini VIII spacecraft with the Agena target vehicle, the first-ever linking of two spacecraft together in Earth orbit. This crucial spaceflight technology milestone would prove vital to the success of future moon landing missions. via NASA http://ift.tt/1VcGwFr

The remotely controlled Sally Ride EarthKAM aboard the International Space Station snapped this striking photograph of South Africa on Feb. 9, 2016. The EarthKAM program allows students to request photographs of specific Earth features, which are taken by a special camera mounted on the space station when it passes over those features. via NASA http://ift.tt/1RLHIu8

NASA’s Cassini spacecraft captured this view of Saturn’s moon Enceladus that shows wrinkled plains that are remarkably youthful in appearance, being generally free of large impact craters. via NASA http://ift.tt/22dWNj0