The landslides were spied by the Mars Reconnaissance Orbiter during a routine tracking of seasonal changes. The probe arrived at the planet in 2006.
It is rare for scientists to catch a natural event in action on the surface of Mars. Most of the landscape that has been recorded so far has not changed much in millions of years.
The avalanches occurred near the north pole and broke part of a 2,300-foot cliff.
"We were checking for springtime changes in the carbon-dioxide frost covering a dune field and finding the avalanches was completely serendipitous," Jet Propulsion Laboratory scientist Candice Hansen said in a statement.
Scientists were unsure what set off the avalanches and whether they occur frequently or only during the spring.
