For the first time since Mars has been under surveillance, scientists were surprised to witness something unprecedented: an active avalanche near the planet’s North Pole. The images were captured with the help of the High Resolution Imaging Experiment camera (HiRISE) on NASA’s Mars Reconnaissance Orbiter on February 19.

So far, the only images scientists have had on Mars were nothing but static, scenery reminiscent for millions of years. “It really surprised me,” said Ingrid Daubar Spitale of the University of Arizona, the first to notice the phenomenon. “It’s great to see something so dynamic on Mars.”

The camera captured not one, but al least four Martian avalanches while tracking for seasonal changes: “We were checking for springtime changes in the carbon-dioxide frost covering a dune field, and finding the avalanches was completely serendipitous," said Candice Hansen, deputy principal investigator for HiRISE, at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The cause of the landslides remains unknown, as well as the conditions they appeared in, but scientists are planning to further investigate the phenomenon and establish whether it is restricted to one season in particular or they occur all year round.

What they do know is that the avalanches, or landslides, involve layers known to be rich in water ice, and dust as well in the upper portion of the scarp. Scientists believe that one way of understanding the water circle on Mars is by studying these phenomena closely.

According to the scientists involved in the HiRISE project, if blocks of ice broke and fell, the water should be changing from solid to gas, which is exactly what they will be looking for from now on.

Up until this point, the Mars mission (the spacecraft landed on the Red Planet in March 2006), proved to be the most successful mission so far, after sending to Earth the highest amount of data, and things won’t stop here.

Image credits: NASA