Moon bounce

By Phil Plait | November 9, 2012 7:00 am

Of all the amazing pictures returned from the moon by the Lunar Reconnaissance Orbiter – and I may include the Apollo landing sites among them – I think my favorites are the ones showing boulders that rolled down slopes.

Did I say rolled? I mean bounced!

[Click to enselenate.]

This shot from LRO shows the floor of crater Shuckburgh E, an impact crater about 9 km (~6 miles) across. The image shows a region about 655 meters (0.4 miles) across. The crater floor here is not level; it’s tilted up from left to right, and also has contours. Boulders dislodged for some reason (a seismic event, or a nearby impact) on the right have rolled down to the left… and some actually skipped along, bouncing and bounding as they did.

The two biggest trails are dashed, indicating the boulders had a bit of a rollicking time before coming to rest. You can see both boulders at the left of the trails, where they came to a stop. Note that the sunlight is coming from the bottom of this picture, which can play tricks on perspective. I see the boulders looking almost like craters and the skidding trails they left like little mounds. If you flip the picture over it may look better to you.

As always, pictures like this are a strong reminder that even on the Moon, where time stretches long and processes are slow, changes do occur. Maybe not often, and maybe not recently, but given enough time you have to think of the Moon as a dynamic place.

Image credit: NASA/GSFC/Arizona State University

Related Posts:

Lunar boulder hits a hole in one!
Excavating a long-dead lunar fire fountain
A lunar crater is graben the spotlight
Peaking into lunar craters

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Comments (18)

  1. Alex W.

    The sun’s to the bottom right in the image, right? I assumed that the big white patch was a hill catching the sun, which threw me and made it seem like the boulders had left lumpy trails behind them. I guess it’s actually a depression.

  2. Nigel Depledge

    In ham radio parlance, “moonbounce” is a technique for getting VHF and UHF signals (that do not usually propagate through ionospheric refraction the way shortwave signals do) from one side of the planet to the other. It usually involves large antenna arrays.

  3. Captn Tommy

    Ed Shuckburgh? How the heck did he get a crater named after him?

  4. Chris

    @3 Captn Tommy
    Actually it’s named after George Shuckburgh.,_6th_Baronet

  5. timbebinder

    At last, lunar change I can believe in.

  6. Jenn D.

    You couldn’t flip the picture for us? I’m on a laptop, can’t easily turn the screen upside down.

  7. Lenny

    Brilliant, to me the most fascinating thing about this picture is the optical illusion of the mounds vs craters.
    No matter how much i stare at it, or how many times i rotate it I still see mounds one way and craters the other.

  8. Manuel

    Mr. Plait can you elaborate on the news from NASA that states it will unveil a manned moon mission and among other missions?

  9. Tara Li

    @Alex – actually, I think that’s a case of lighter exposed regolith from the cluster of small impacts located at the center of it. Maybe a smaller, rounder version of Tycho’s rays. Not all color variation comes from elevation changes, after all.

  10. Markus

    Examples of such boulder traces can be found in old Lunar Orbiter images as well. Years ago these used to prompt The Usual Conspiracy Theorists With A Geocities Homepage out there to come up with sensationalist crap along the lines of “Ancient Alien Machines Left Rover Tracks On The Moon!!!!1!!” (and of course NASA knows it and lies about it, yadda yadda…)

  11. CatMom

    RE: Markus – actually, it’s where Alan Shepard putted the ball a looooong way and put it right into the cup. :)

  12. Grizzly

    It’s a wonderful night for a moon bounce…

  13. wright1

    Magnificent image. Those bounce / roll tracks are so eloquent!

  14. Messier Tidy Upper

    @6. Jenn D. asked : “You couldn’t flip the picture for us? I’m on a laptop, can’t easily turn the screen upside down.”

    Can you do handstands? Or cartwheels and have a quick glance mid turn, mid air? 😉

  15. Andrei

    @2 Nigel
    That was the first thing I thought also when I first saw the title. And then when I first saw the picture I thought of being maybe a radar image of the moon – a continuation of the impression of radio bounce on the moon surface.

  16. @Messier – what’s wrong with just making the laptop levitate upside-down? Why are you people always finding the most complicated ways imaginable to do things?

    Remember, the SIMPLEST way that works is the best.

  17. Peter

    This obviously is one of Alan Shepard’s golf balls.

  18. Matt B.

    @6 Jenn D. – Right-click on the picture and select “Copy”. Then open Paint if you’re using Windows, and paste. Then you can rotate the picture there by 90 degrees at a time.

    By the way, if you want an astronomy-themed handle to use here, you could go with “Solar Jenn”, a name that a friend of mine came up with for a superheroine. I was thinking of switching to something clever when BA goes to Slate myself.


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