Unmanned landing sites from LRO, Surveyors, Lunas, Lunakhods and impact craters from hardware impacts Options

[dvandorn]

I figured it was time to begin a thread like this, especially since some of us may still be looking for the Surveyor III retro motor casing (assuming the bright dot to the north of the landing site isn't it).

We ought to be seeing some of the other Surveyors fairly soon, I would think. We know most of their locations pretty accurately. Again, I think there is a lot to be gained, both from scientific and engineering standpoints, from detailed imaging of the Surveyor VII landing site, just to mention one. And I really want to see how visible the Lunakhod tracks are as opposed to the MET and LRV tracks.

So... until we begin to see images of other unmanned hardware (or the craters caused by same), we could always discuss comparisons of Surveyor III surface imagery to the new LROC images of its landing site here. I'm especially taken by how you can resolve many of the blocks in Block Crater in the LROC image, which gives you a good feel for the explosive nature of the ejecta and roughly where in the ejecta plume a given block might have come from. Might be interesting/useful to apply this information to the samples taken at that location.

-the other Doug

[Phil Stooke]

OK, I have been pondering this. Ponder, ponder - there, I just did it again.

Here is my guess for Surveyor 4:




This shows the Surveyor 4 target as it evolved from before launch to after launch (when they had a better idea of the trajectory and could shrink the landing ellipse) and where tracking suggested it actually went. The failure came at or just before the end of the retro burn, which did most of the job of bringing it to the surface, so it should be fairly close to the tracking location.

The site I zero in on shows two little dark spots. When you start looking at the high sun LROC NAC images there are a surprising number of little dark spots and it is not at all easy to decide which to pick. My rationale is that the retro burn was probably completed and the failure occurred when the small vernier thrusters took over from the retro system. Therefore I assume the retro engine fell to the ground as expected rather than exploding into fragments. So I was looking for a place where there were two dark spots, one for the lander and one for the retro rocket system. The one I found has two spots about 200 m apart, which is roughly what we see for the two where we know we have it right from before/after images (Surveyor 3, Surveyor 6). But other searches might find different candidates.

Shan's point is close to the target but quite a long way from the tracking location. So I still prefer mine for the time being. But I will change my mind if someone finds a better candidate.

Phil