This was
your sky.

Dark Sand Cascades on Mars

These dark streaks on Mars might resemble trees, but they are actually sand cascades. Photographed by the Mars Reconnaissance Orbiter near the Martian North Pole in April 2008, these formations appear on melting sand dunes. As the spring Sun warms the surface, lighter carbon dioxide ice melts, revealing the darker sand beneath. This dark sand then slides down the dunes, creating these distinctive patterns.