Scientists believe it happened when the area began to thaw in local spring.
Rock, ice and dust were sent plummeting 2,300 ft causing a cloud of fine debris to billow to a distance of 625 ft.
The top of the cliff is still covered with bright carbon dioxide frost – the dry ice used to create “smoke” at rock gigs.
Spacecraft orbiting Mars have taken thousands of photos of the planet’s surface. But they mostly show an unchanging landscape. All the more surprising then that the spectacular avalanche was one of four falls spotted in one wide scan of the zone at a latitude of around 84° N.
The photo, just released, was taken on February 19 from orbit around Mars by HiRISE, the most powerful camera ever sent to another planet, operating on board NASA’s Mars Reconnaissance Orbiter.
HiRISE scientist Patrick Russell said: “Cameras orbiting Mars have taken thousands of images that have enabled scientists to put together pieces of Mars’ geologic history. However, most of them reveal landscapes that haven’t changed much in millions of years. It is extremely rare to catch such a dramatic event in action.”
