The soft avalanches of Mars

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Krupac Crater gullies

Cool image time! The image on the right, reduced in resolution to show here, shows the gullies flowing down Krupac Crater on Mars. Be sure to check out the original, released today by the Mars Reconnaissance Orbiter science team, since they have enhanced the colors to bring out the sandy flows, noting as well that while most of these gullies are found in higher latitudes, this crater at 7.8 latitude has them as well.

Although large gullies (ravines) are concentrated at higher latitudes, there are gullies on steep slopes in equatorial regions. An enhanced-color closeup shows part of the rim and inner slope of Krupac Crater located just 7.8 degrees south of the equator.

The colors of the gully deposits match the colors of the eroded source materials. Krupac is a relatively young impact crater, but exposes ancient bedrock. Krupac Crater also hosts some of the most impressive recurring slope lineae (RSL) on equatorial Mars outside of Valles Marineris.

Below I have cropped out a small section showing, at full resolution, the termination point of one of these flows, indicating where this section is on the larger image to the right. This avalanche is clearly not liquid, though it has a very sandy and soft nature, suggesting — as some scientists have theorized — that liquid from below the surface might have played a part in its flow.

It is important in looking at these images to repeatedly remind yourself that the gravity here is about one third that of Earth, and thus the angle of repose will be different, and that avalanches will behave very differently in this environment. Moreover, Mars’s far colder climate will also effect things. The avalanche we are looking at could not happen in this way on Earth.

close-up of flow



  • LocalFluff

    Amazing imaging!

    Congress a few days ago ordered NASA to include a Mars helicopter on its 2020 rover. Here’s a talk by the mission manager of (what I’m sure of is) that Martian helicopter. They did make it fly in a chamber with Mars’ atmospheric density. If this actually works it could dramatically increase the productivity of rovers. AND examine steep slopes where no rover can roll.

  • LocalFluff

    Okay, here’s the link to the lecture:

    I hope NASA doesn’t forget things as easily as I do. It would be a bit embarrassing to launch this thing, just to discover a bit later that the spacecraft is still in a garage at JPL.

  • LocalFluff: The lecture you linked to was a presentation describing the proposal only, by the scientists proposing it. She says right at the beginning that the proposal has not yet been selected. Where did you see anything about Congress ordering this? Please provide a link.

  • LocalFluff

    Robert, I just assume it is the same project. NASA can’t have multiple conceptual Mars helicopter missions going this far through their technology readiness levels. That talk was 2 years ago. Now it seems that it has been selected. By none less than the Congress! They legislate that a helicopter must be put on Mars. Seems like one team cornered that market.

    And it was more than a proposal, they did test fly a prototype in simulated Martian atmosphere. It is happening! Air force on Mars. We’ll see if they can put it on the 2020 Mars rover this late in the game. I suspect it was provided for to begin with.

  • LocalFluff: I repeat my question: What is your source for your claim that Congress has mandated that NASA put a helicopter on Mars? I haven’t seen any stories like this anywhere, and if true I want to read them. You need to provide a source or link. Otherwise, you are just spouting off silliness based on nothing.

  • LocalFluff

    Oh, I took it for granted that *a* Martian helicopter has been financed. That’s why I assumed it was the specific one I linked to the talk about.

    Here is a link to the very recent news that Congress orders a helicopter to Mars:

    “Planetary science wins a large increase, to nearly $1.85 billion, well above the 2017 request of $1.52 billion and the $1.63 billion it received in 2016. That total includes $408 million for the Mars 2020 rover mission, including language directing NASA to add a small helicopter technology demonstration to the mission as long as it does not delay the mission’s launch.

  • LocalFluff: Thank you. What this means is that NASA is to try to put this drone on the next rover, but has the freedom to pull it if the agency doesn’t think it will be ready in time.

  • wayne

    “Tiny NASA Helicopter Drone Could Explore Mars One Day”
    January 2015

  • Wayne: As this article is from 2015, the same time that the presentation that LocalFluff linked to, it does not give us any up-to-date information on the status of this drone idea.

    I remain skeptical that this drone will fly on the 2020 rover.

  • LocalFluff

    I’m hopeful. It is a very independent “instrument” that could be added without messing too much with the rest of the rover. They could even land separately. And I’d think that designers have had this option in the back of their head all along since it is an “old” idea. I’m amazed if it really works in the 0.6%-1% of Earth’s atmospheric density. One jump a day would be big leaps for Mars exploration.

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