A NASA spacecraft has taken the first-ever image of an avalanche in action near Mars' north pole. -- The High Resolution Imaging Experiment (HiRISE) on NASA's Mars Reconnaissance Orbiter took the photograph Feb. 19. The image, released today, shows tan clouds billowing away from the foot of a towering slope, where ice and dust have just cascaded down.

The camera was tracking seasonal changes on Mars when it inadvertently caught the avalanche on film. -- HiRISE mission scientist Ingrid Daubar Spitale of the University of Arizona was the first person to notice the avalanche when sifting through images.

"It really surprised me," she said. "It's great to see something so dynamic on Mars. A lot of what we see there hasn't changed for millions of years." ...   more »