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Snowy dunes on Mars.

Over the winter, snow and ice cover Martian dunes…and unlike on Earth, this snow and ice is carbon dioxide… a.k.a. dry ice. When the Sun starts shining on it in the spring, the ice on the smooth surface of the dunes cracks and escaping gas carries dark sand out from the dune below, often creating beautiful patterns. On the rough surface between the dunes, frost is trapped behind small sheltered ridges. Seen by our Mars Reconnaissance Orbiter, this image was taken over the Northern hemisphere of the Red Planet. Credit: NASA/JPL/University of Arizona
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Rhea is a heavily-cratered, airless world, while Titan’s nitrogen-rich atmosphere is even thicker than Earth’s. This natural color image was taken in visible light by the Cassini spacecraft on Nov. 19, 2009, at a distance of approximately 713,300 miles (1,148,000 kilometers) from Rhea. After a nearly 20-year mission that overflowed with discoveries, the Cassini spacecraft ended its mission on Sept. 15, 2017. Credit: NASA/JPL-Caltech/Space Science Institute

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David Benioff and D.B. Weiss are going from #Westeros to a galaxy far, far away. Click the link in our profile to learn more.