A closeup of an impact crater shows distinctive bright lines and spots on the steep slope, indicating bouncing boulders have fallen down the incline. Credit: NASA/JPL/University of Arizona.

Tell-tale Evidence of Bouncing Boulders on Mars

10 Apr , 2013 by

What are the types of things that happen on Mars when we’re not looking? Some things we’ll never know, but scientists with the HiRISE camera on the Mars Reconnaissance Orbiter have seen evidence of bouncing boulders. They haven’t actually captured boulders in the act of rolling and bouncing down the steep slope of an impact crater (but they have captured avalanches while they were happening!)

Instead, they see distinctive bright lines and spots on the side of a crater, and these patterns weren’t there the last time HiRISE imaged this crater 5 years ago (2.6 Mars years ago), in March 2008.

“The discontinuous bright spots indicate bouncing, so we interpret these features as due to boulders bouncing and rolling down the slope,” said HiRISE principal investigator Alfred McEwen, writing on the HiRISE website.

Where did the boulders come from?

“Maybe they fell off of the steep upper cliffs of the crater, although we don’t see any new bright features there that point to the source,” McEwen said. “Maybe the rocks were ejecta from a new impact event somewhere nearby.”

The trails are quite bright, and McEwen said that perhaps the shallow subsurface soil here is generally brighter than the surface soil, just like part of Gusev Crater, as the Spirit rover found. McEwen added that the brightness can’t be from ice because this is a warm equator-facing slope seen in the summer.

Source: HiRISE


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April 10, 2013 10:47 PM

This is another great reason to just keep imaging over and over the surface of Mars and the planets in general! Each occurrence tells a short story, an adventure, or a mishap and we benefit by learning more about both Mars and our own planet as well. Superb.

April 11, 2013 1:09 AM

I hope we can gain more knowledges about Mars surface

Mpj Marsphotojournal
April 11, 2013 8:15 AM

That was one of my first interesting observations back then I started to view the HiRISE imagery in detail (jpg2000): There are a lot more interesting things in the HiRISE imagery though! smile

Sreejith Ramakrishnan
April 11, 2013 5:12 PM

Doesn’t this happen in any and every rocky world?

April 11, 2013 7:37 PM

I wonder if HiRise will see anything new after comet ISON passes nearby? Inspire a sample gathering mission?

April 18, 2013 4:46 PM

sometime i look into the sky and ask myself that what universe is