There are conflicting stories about Luna 18 (landed on a slope and fell over, ran out of fuel as it descended) but they all seem to agree it was already travelling quite slowly (by orbital standards) as it came in for a landing. Any crater should be small, and it might have landed nearly intact and not made much of a crater, just broken up.

I don't think this can be the right feature, but I have searched for it and not found anything. Another mystery on the Moon!

First, the crater is not at the indicated coordinates in any image. The coordinates were probably assigned early in the LRO mission and have not been updated as registration has improved. The crater is about 20 m across. Ranger craters were 10 m across, Apollo Saturn upper stage craters were 40 m across. This might be OK for something coming in fast like those things, but it's too big for something which was braking for a landing So what happened to Luna 18?

The crater can't be seen in that last map but here I zoom in on it. The blue dot is the indicated latitude and longitude. Note how it seems to move relative to the craters... but this is deceptive. It's the craters which are moving, the point is fixed. Each image (from 3 separate NAC layers in Quickmap) is registered to the coordinate grid differently, illustrating how uncertain coordinates are in this or any other map. But is it the right crater? #moon #luna18

The NSSDCA link yesterday says the Luna 18 impact was tracked to c. 3.57 N, 56.50 E, and that LRO shows a crater which may be the impact site at 3.76 N, 56.66 E.

My map, from Quickmap, shows those locations and Luna 20's landing site. I had not seen the impact crater suggestion until right now when I looked it up for you, dear reader. I think it's a bit too far from the tracking position but not impossible. Let's take a closer look...
#maps #moon #luna18

Moving on to Luna 18 now... this was another sample return mission like Luna 16. The area accessible to these sampling missions was very limited and within it was Mare Fecunditatis, sampled by Luna 16, and a highland region north of it which was another obvious target. NSSDCA has a description of the mission here:

https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1971-073A

Things were going wrong during the flight and Luna 18 failed at some point during the landing attempt. Can we find it? #moon #luna18