In a separate thread I uploaded a photo of a lunar scene showing astronauts or their equipment in the foreground while on a hill in the background you can see a rock that has rolled downhill. I don't know how to post more than one photo at a time so I had to post this closeup separately.

you know, you could just post it in one thread. this looks like spamming now =/

OkayProbably a stupid question but i'll bite. Why would a rock roll on the Moon? ...Dont you need an atmosphere or seizmic activity to make things move about

there is gravity on the Moon, so why wouldn't a rock roll?

BTW, is there a source for the picture?...

I understand that there's gravity....but if you had say two rocks on Earth and one was finely balanced on top of the other ...it would never move unless there was an external force to move it...such as wind , vibration etc ...if gravity would move it ...it's not balanced.
So my point is this...if gravity is going to move stuff on the Moon shouldn't it have finished after any seizmic activity there finished?.

it's clear the Moon has been bombarded by meteorites for a long time, how can anyone say when the rock rolled or what the impetus was?

maybe it was hit by a meteor causing a slight moonquake...its possible

Sorry I failed to list the source. I took the photo of the photo found in "APOLLO OVER THE MOON: A VIEW FROM ORBIT" - NASA SP-362, published in 1978, page 53. This is a closeup of the main picture which is AS17-136-20694 and which I had to list separately because I tried to upload both photos but only 1 appeared.

NOTE: The URL doesn't show complete so between apollo and ?AS17-144-22129 enter /frame/
You can also see it at: http://www.lpi.usra.edu/resources/apollo/f...?AS17-144-22129

To clear up the air about why a boulder would roll down a hill in an airless world, here is what the book says about the photo: "This a closeup view of part of the boulder track shown in figure 40 [Skepticaled: figure 40 is the main or overall photo AS17-136-20694]. The track is about 10 m wide and the boulder that made the track is abut 18 m in diameter (Mitchell et al., 1973).The cause of movement, othr than the obvious effect of gravity, is uncertain. Various investigators have suggested that movement was initiated by seismic vibrations of internal origin, vibrations caused by repeated impact events, cyclic thermal expansion and contraction, and instability as soil acccumulates above the boulder or is removed from below it. It is also possible that some of the tracks are formed by projectiles, presumably from impact craters, that skid or bounce along the surface before coming to rest. From detailed studies of boulder tracks, some properties related to the strength, density, and thickness of the lunar soil can be measured. - G.W.C.

The main photo (AS17-136-20694) can be seen on another thread much better than here, where it is seen as a small photo without boulder detail [NOTE: I don't know what the technical problem is on the forums but URLs are not being reproduced in their entirety. So, in the URL below between apollo/ and /magazine enter catalog/70mm]: http://www.lpi.usra.edu/resources/apollo/c...m/magazine/?136

In a science report I read on Apollo 17, it described the evidence for the possibility that the Crater Tycho impact (100 mya) sent material into the Taurus-Littrow region.

I certainly have no idea whether those tracks are that old, but who knows?

Thanks for the explanation Scepticaled
Bogey