Martian landslide

An avalanche of rock and ice slid down a cliff at the edge of Mars's north polar ice cap moments before this picture happened to be taken. The landslide sent a cloud front of dust 600 feet (190 meters) long billowing down the gentler slopes beyond.

NASA / JPL / University of Arizona

Last summer I stood on the deck of a boat off Alaska watching the face of a glacier. We couldn't actually see the glacier moving, but moving it certainly was. Every few minutes a small piece of the white cliff would crumble, smash to rubble as it slid down in slow motion, and hit the ocean with a booming roar. In between times, the cliff face was pregnant with menace and suspense. We wondered if we were too close for safety. That ice was on the move.

The same thing seems to be happening, more or less, along a cliff face at the edge of Mars's north polar ice cap. Aboard the orbiting Mars Reconnaisance Orbiter, the powerful HiRise Camera (the best ever to orbit another world) took an enormous, high-res image that included a long polar cliff. Amazingly, the image caught four widely separated landslides in progress along the 2,300-foot-high cliff — all at once! That's one place on Mars I wouldn't want to be exploring on foot.

"It really surprised me," says discoverer Ingrid Daubar Spitale. "It's great to see something so dynamic on Mars. A lot of what we see there hasn't changed for millions of years."

Read all about it — and download incredible high-res images — at today's news posting from the HiRise Camera team. NASA has also put out a Science@NASA news story.

Comments


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Marc

March 5, 2008 at 2:35 pm

"A lot of what we see there hasn't changed for millions of years."
Sigh...
Why are those millions of years still taken for granted? It's Theory!
You begin to see with your own eyes that Mars is a dynamic, moving planet (like all of 'em are) and you still think nothing changed in millions of years... well, the coming time we'll be seeing more unexpected movement.

Beautiful, all this imagery, really! But don't present theory as a fact. Please? In the name of science...

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James Juno

March 7, 2008 at 11:21 am

Marc - Of course it's science. The topography of Mars is millions of years old! Do you really believe the hundreds of thousands of impact craters on impact craters on Mars were all created within the past, oh I don't know, 6,000 years? I'll never understand why some folks refuse to accept the volumes of data (like radioactive isotopic dating, stratigraphic measurements, nuclear physics of stellar process, etc etc etc) that indicate both quantitatively and qualitatively the passage of great stretches of time. It scares me, frankly.

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James Helmer

March 7, 2008 at 11:21 am

Rotate the image 90° CCW and it looks much more realistic.

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Brian

March 7, 2008 at 11:55 am

Notice how low gravity and negligible atmospheric pressure allow for such a large plume of dust from what was a fairly small rock and ice slide. It's difficult to measure scale here. Was the slide of rock a volume of a handful (~60 cubic centimeters) or a truckload (~60 cubic meters) or more than that? Anyone care to make a guess-timate?

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Image of Brian

Brian

March 7, 2008 at 11:55 am

Notice how low gravity and negligible atmospheric pressure allow for such a large plume of dust from what was a fairly small rock and ice slide. It's difficult to measure scale here. Was the slide of rock a volume of a handful (~60 cubic centimeters) or a truckload (~60 cubic meters) or more than that? Anyone care to make a guess-timate?

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