Curiosity Meets Martian Dunes

In December, the rover Curiosity reached some sand dunes on Mars, giving us the first views of these dunes taken from the ground instead of from above. It’s impressive how the dune seems to shoot straight up from the rocks here!

In fact this slope—the steep downwind slope of one of “Bagnold Dunes” along the northwestern flank of Mount Sharp—is just about 27°. But mountaineers will confirm that slopes always looks steeper than they are.

The wind makes this dune move about one meter per year.

For more, see:

• NASA, NASA Mars rover Curiosity reaches sand dunes, 10 December 2015.

• Jet Propulsion Laboratory, Mastcam telephoto of a Martian dune’s downwind face, 4 January 2016.

• Jet Propulsion Laboratory, Slip face on downwind side of ‘Namib’ sand dune on Mars, 6 January 2016.

4 Responses to Curiosity Meets Martian Dunes

  1. Your G+ post had me reading all sorts of things about the differences in the “angle of repose” between Earth and Mars. Which theoretically isn’t gravity dependant although there’s some evidence (including the photo in your post) that there are in fact differences.
    I was ready to enjoy the conversation on your G+ post and noticed, sadly, you’ve disabled your comments. Please reconsider.

    • John Baez says:

      Yes, the dependence—or lack thereof!—of the angle of repose on the acceleration of gravity is a fascinating puzzle. I’d forgotten that when posting this article. What did you learn about this?

      I no longer enable comments on any of my G+ posts. For reasons explained here, I find G+ to be a frustrating place for conducting conversations. I don’t want to spend time there anymore. So if people want to talk to me, they’ll have to come here, or send me an email. I just post things on G+ to remind people that I still exist.

      (Actually it’s a bit more complicated than that. I had tried to set up a system where my posts here would automatically be copied to G+ and comments there would be automatically be copied here. That could be nice, and I’d been told it was possible. But I was unable to get it to work, perhaps because I’m not naturally talented at such things and have little patience for them. So, I gave up.)

  2. I’m imagining a news item a thousand years from now: “The trailing side of a dune is now approaching the site where Curiosity broke down, raising hope that the old probe might soon see daylight for the first time in centuries”

    If terraforming doesn’t interfere.

    • John Baez says:

      That would be cool. A bit like Ötzi the Iceman:

      Five thousand years ago in the European Alps, a man was shot by an arrow, then clubbed to death. His body was subsequently mummified by ice until glacier retreat exhumed him in 1991. Subsequently, this ancient corpse has provided a trove of intriguing information about copper-age Europeans. Now, Maixner et al. have identified the human pathogen Helicobacter pylori within the mummy’s stomach contents. The strain the “Iceman” hosted appears to most closely resemble pathogenic Asian strains found today in Central and Southern Asia.

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