Rocks Rolling on Mars

This image covers where the southern branch of Shalbatana Vallis opens into Chryse Planitia, showing a variety of boulders that have moved down slope leaving tracks on the surface. These boulders may have been thrown out from low-energy secondary craters, or simply eroded out of the above rocky cliff.

the left frame shows boulders moving in two directions, indicating that they had different sources. The right frame shows a boulder about 4 meters in diameter in the bottom left, having left a track that begins in the upper right. This boulder rolled down the hill, appears to have jumped the crater, bounced a few times, and then rolled to a halt.

Source

Earlier it was the avalanche on Mars that amazed every one of us; but now it is Rock rolling. What would be next? I am all excited.

In this High Resolution Imaging Science Experiment (HiRISE) on board NASA's Mars Reconnaissance Orbiter (MRO) when the instruments caught this Rock rolling down the hill. This rock rolled down a crater side on Mars leaving its track visible in the picture. No body knows what triggered this event.

That's very cool. I would have liked to be in that crater watching that 4-meter boulder fly over my head.

I usually smack my golf putts so hard that they end up flying over the hole more often than they go in (that's if I even get near the hole at all).

If I were to guess what causes these boulders to move, I would say a combination of wind and gravity. What I mean is this: we know Mars often has sandstorms. During these storms, It is possible that sand under some large boulders sitting on the edge of a crater gets blown away until there is very little sand remaining to hold up that boulder. Then gravity takes over and the un-supported boulder falls into the crater, picking up speed as it rolls down the crater's wall.

It's not the first time I see rolling rocks on photos from HiRISE.

The first was this one, PSP_001415_1875.



The second was PSP_001640_2125, with many examples of rolling and "jumping" rocks.

I love those HiRISE images, I am trying to collect them all (4568 at the time, I only have 1006).

Great Images!

Certainly food for thought! I seem to remember seeing something similar years ago though I can't remember if it was the Moon or Mars. Does anyone know of rolling boulders/rocks on the Moon?

Now that would be even more interesting!

S&F from me!

reply to post by InfaRedMan


Probably on the Moon, probably part of image 5168_h2 from Lunar Orbiter.

reply to post by ArMaP


Great Pic ArMaP!!!

Thanks for clearing that up!

That is indeed the very image I have seen before. You must be psychic!
Unless it was on an extremely steep hill I can't see the Moons low gravity playing a part. Out of interest, what is your conclusion on this picture? How do you think it occurred?

A slow moving meteorite that came in shallow, managed to stick - and was decelerated by the friction of the moons surface perhaps?

I look forward to reading your wise and rational theory!

Cheers,
IRM

reply to post by Enceladus

Enceladus, thanks for sharing these amazing images and for presenting them properly: i'm glad to see that someone is still using common sense rather than making outrageous claimings. I hope that these images won't be seen by someone i have in mind: in the wrong hands, these images may become alien vehicles on Mars.
Star and flag.


[edit on 8/4/2008 by internos]

Originally posted by internos
these images may become alien vehicles on Mars.

Thanks for the laugh of the day internos. We don't know what your talking about.

Great pics, thanks for sharing. Reminds me of the moving rocks in the dry lake beds here on earth that were once mysterious.

[edit on 8-4-2008 by verylowfrequency]

Originally posted by verylowfrequency

Originally posted by internos
these images may become alien vehicles on Mars.

Thanks for the laugh of the day internos. We don't know what your talking about.

Internos, Its all pleasure to bring some of those important events happening in our time; I may not understand the whole event but I am sure of one thing; if i could bring them to ATS, the professionals here would teach me the rest; thanks for your comment.

reply to post by ArMaP


Thanks for adding those amazing pictures and the information you provided; This is why i love to be in ATS; there are many others who can provide you with more details. ArMaP, have you got any idea what makes them roll like this?

Ency

Originally posted by Soylent Green Is People

If I were to guess what causes these boulders to move, I would say a combination of wind and gravity. What I mean is this: we know Mars often has sandstorms. During these storms, It is possible that sand under some large boulders sitting on the edge of a crater gets blown away until there is very little sand remaining to hold up that boulder. Then gravity takes over and the un-supported boulder falls into the crater, picking up speed as it rolls down the crater's wall.

Bright chances and you have some valid points there; but during the time of capturing this photos we hardly had any sand storm formation in that particular area; if there was any, I am sure they would have mentioned it in the website. They did mention about some meteorite activity could have triggered this rolling event.

reply to post by Enceladus

There was a sandstorm a few months ago, and we don't really know WHEN these boulders rolled (do we? -- I could be wrong). If they rolled into the crater soon after that sandstorm event a fews months back, then the trails would probably still be visible, since there is very little other weather on Mars that could have obliterated the trails -- especially since they are "protected" from the wind a bit inside the crater.

More on the Moon than on Mars, I think the most probable reason is the change of temperature.

I suppose that a rock on the Moon can get very hot when it gets sunlight and very cold when in the shadow. The change in temperature, like on Earth, must be responsible for many of the broken rocks we see on the Apollo missions photos, and maybe the reason for some of the strange shapes (I never had thought of that until this moment).

A rock that is supported by another that breaks would loose its support, rolling down hill if it gets enough momentum.

There are also Moon-quakes, very week when compared to those of the Earth, but probably strong enough to shake some rocks.

Ans we don't know if that rock rolled down hill (or up hill, like some people say) the day before the photo was taken or one million years ago, the lack of erosion makes us loose one of the ways we use on Earth to date rocks and ground layers.

Another thing to remember is that, because of the smaller gravity, the slopes on the Moon and on Mars are steeper than on the Earth, so when things fall, although they accelerate slower than on Earth, they have less support and less opportunity of being stopped by something in their way.

Originally posted by verylowfrequency

Thanks for the laugh of the day internos. We don't know what your talking about.

Did you mean: I don't know what you're taking about?
doesn't matter to me, if YOU don't understand.

Originally posted by internos

Did you mean: I don't know what you're taking about?

doesn't matter to me, if YOU don't understand.

Yes, that was the intended reference in response to your unintended humor, but the "We" was for everyone here, as your cryptic message had enough clarity that even a relative newbie like myself understood.

I only commented because you made me laugh, no disrespect was intended. I do appreciate your work - whether or not you care.


As far as the rocks moving: If the rocks that leave these kind of tracks on earth do so because the ground freezes overnight & the ice elevates the rocks then acts as a lubricant while melting and even with light wind or slight grade, I would expect the same to be true on similar landscapes elsewhere.


[edit on 9-4-2008 by verylowfrequency]

Originally posted by verylowfrequency


Yes, that was the intended reference in response to your unintended humor, but the "We" was for everyone here, as your cryptic message had enough clarity that even a relative newbie like myself understood.

I only commented because you made me laugh, no disrespect was intended. I do appreciate your work - whether or not you care.

Ok, sorry for the misunderstanding: honestly, not all may get it
my message was intentionally sarcastic: i was refering to someone who usually inject the trheads on Mars with random images, but more in general the meaning is:
Enceladus has putted as title "Rocks Rolling on Mars"
someone else, would entitle it "alien vehicles on Mars?"
This is what i meant.


[edit on 9/4/2008 by internos]