Once I forgot, it is appreciated for the relevant discussions that have taken place with the supplied data and hope that we shall not be in the pit to formulate theories that are nothing but nonsense.
I'm not trying to explain how this stone moved. Instead, I will point out what the soil is loose and soft, see, for example, this tiny stone that seems to have blown by the wind or been thrown and leaves a fine line on the surface, for this to occur must the surface layer have to be very fine and light.
Perhaps some of those rocks where moved by the rover however if that's not the case then there must be some other forces at work on Mars similar to Earth and Moon. There have been many ideas such as condensation, high-winds, ice or frost, flooding, even a slippery cyanobacteria sheath that somehow allows the stones / boulders to propell in different directions. Regardless, this thread reminded me of some photos from the lunar surface and also the moving rocks of Death Valley, US:
Hi, would you please add direct links to the images . Which explanations are given by science for the moving rocks of Death valley ?
Thank you very much. osd
-- Edited by One single drop on Wednesday 16th of March 2011 12:29:31 PM
Just to show you what I mean about both larger and tiny rocks having the same tracks behind them, (see the original link in the first post) I have enlarged the tiny track to the same kind of size as the larger one.
You can see the similarity one to the otherbut it is not a terribly good illustration because one is so smuch smaller than the other. This means that when it is enlarged, it loses most of the definition.
Any blast strong enough to blow the larger rock over would have totally blown away the smaller tiny particle (at the larger rock's 10 o'clock position) which also has the same shaped track.
A blast would have cleared the area of smaller particles and any that had initially been in the lee of a rock would not be in the lee of the rock once the larger itself started moving.
I do not think this is a reasonable nor logical scientific explanation of this phenomena since both large and tiny rocks have the same track behind them.
I do not know if this actually addresses the issue because I would have thought that something pushed by a blast of landing rocket exhaust will have a uniform trail and will not show separate indents.
If you are saying that it was pushed so that it rolled, then that is a different matter entirely. I believe that to roll a rock requires far more "up-and-under" force than a straightforward "push" and it does look as if the original rock has been rolled more than once because of the indentations in the track.
The other thing I wonder about is, why are they moved in a circular way rather than straight? The landing rockets do not move that much in relation to the rock to account for a semi-circular track perhaps?
With this in mind, is this still a valid explanation of this phenomena?
Nope. This rock (named "King's Horses") as well as several others were blown a few inches across the surface presumably as a result of the landing rockets. They showed this characteristic trail when the ground was photographed on the first sol. The arm was not unstowed for several sols after landing. The digger arm had nothing to do with this anomaly.
Here's a panorama in cylindrical projection from Sol 1.
Source: S_001EDN_CYL_SR10D0E_R111M1 retreived from Planetary Data System
King's Horses is half in shadow close to the (0, -50) mark. If you can't read the numbers, it's the rock half in shadow just left of center. The trail is in shadow, but can still be seen. Another unnamed rock has skittered across the surface on the left, right by the edge of the lander.
The tiny rock that gbull has shown with a similar skitter trail is further evidence that the rocks were moved by the descent motor.
Images throughout the mission show these trails of moving rocks to have been there from the landing, and not as a result of being moved by the digger arm.
I tell you what - I have seen some amazing things done with full size builders JCBs (diggers) here in China. They even pick up beer bottles without knocking them over. I doubt that they could move a small rock like that with a digger without pushing it into the ground more than that, or without making a digger-mark on the surface.
Does it say anywhere that an unmanned machine was able to move that rock so accurately on its own without any help from humans?
