Wow! I wonder if this area was covered by Apollo CSM or Metric Camera photography?

The crater is only about 2 m across. There are no Apollo images of the area at any useful resolution.

Phil

Excellent find, Phil! That's exactly the kind of image I was looking for.

And, see -- once you locate hardware on the surface, the low sun images are actually helpful in characterizing them. The high-sun images would never have implied the amount of the retro-rocket that survived its final plunge intact.

-the other Doug

I should say that that particular image is one of those taken from the very low orbit a few years ago before LRO moved into its current high orbit. It has a scale of 25 cm/pixel, twice as good as the best we have for any other Surveyor.

Phil

I have an exciting addendum to Phil's Surveyor 3 retro-rocket discovery, as detailed here:

http://www.planetary.org/blogs/guest-blogs...n-the-moon.html

Last night, I came upon the candidate crater formed by the retro-rocket impact in the Apollo 12 descent film:

https://www.youtube.com/watch?v=NlgGveDiqW4

It first appears at 3:24, is best seen around the 3:39 mark, and goes out of frame at 3:51.

A frame culled from the 16-mm film (shot out of LMP Alan Bean's window), is shown below alongside a crop of the highest resolution LRO frame:

Click to view attachment

My thanks to Phil for confirming what I think is a rather interesting find: a man-made crater within walking distance of one of the Apollo landing sites!

OK, it's time to prepare LPSC abstracts for next year. And what do you know, I was working on Surveyor retro-rocket images when I found that my Surveyor 6 suggestion above is wrong, and I found the real thing not far away.

This was the result of looking at Lunar Orbiter images from before the Surveyor 6 landing. LO2 frame 121-H3 reveals that the little spot I identified as the retro-rocket was there before the landing. But another one, the same distance from the lander (300 m) was NOT there before the landing. Eureka! Guess I should have done this earlier. (Unfortunately there are no pre-landing Lunar Orbiter images for Surveyor 1 or Surveyor 5)

Phil

Click to view attachment

Click to view attachment

Oh, yeah -- it looks like you've definitely nailed it. If that's not the Surveyor VI retro-rocket, it's a very, very coincidental impact of exactly the right size, and in exactly the right place, that came from something else.

I still think the items with the highest cool factor would be to find the impact sites of Surveyors II and IV. I know that at least one of them is likely to be a small field of little craters, since it's likely that its solid-fuel retro exploded. But it would be really interesting to see the resulting impacts. (Doubtful they would be discernible, more's the pity...)

-the other Doug

On a related note - not a landing site exactly - news of the Apollo 16 SIVB impact location on the Moon:

http://www.leonarddavid.com/found-impact-s...6-rocket-stage/


The location was very uncertain. I don't have coordinates yet.

Phil

From this link:

http://lroc.sese.asu.edu/posts/894

the coordinates are now available.

Phil

And here is a locator image if you want to find it yourself.

Phil

Click to view attachment

I have been experimenting with making improved images of Luna 17 and Lunokhod 1 for my revised moon atlas. These two images are each composites of eight LROC NAC images, enlarged and registered. The tracks are much more visible than in single images.

Phil

Click to view attachment
Luna 17

Click to view attachment
Lunokhod 1

continuing the theme of improving LRO NAC images by combining several of them... here are two Surveyors:

Surveyor 1
Click to view attachment

Surveyor 3
Click to view attachment

Phil

I had someone ask me about Surveyor 4 today, and the question comes up every now and then. Recently I tracked down a candidate for it, so here it is, with a bit of speculation.

What should we be looking for? There are three obvious suggestions arising from three possible fates for the spacecraft.

1. Successful landing, but power or communications fail. We would see a lander like the other Surveyors, a lump casting a shadow in low sun images, probably surrounded by a bright patch where the rocket exhaust changes the surface - we see that for most landers. Also, a few hundred meters away we might see a dark spot, possibly resolved as a small crater, where the retro-rocket hit the surface after it was ejected.

2. The retrorocket fails to separate and the small thrusters used for landing fail or can't cope with the extra weight. A crash, showing up as a dark spot or small crater, but no separate retro-rocket impact.

3. The retrorocket separates, but one or more thrusters fail to ignite. The lander falls to the surface, with a retro-rocket impact nearby.

What do we see? Here is a map showing the target and a zoom-in sequence leading to my candidate site:

Click to view attachment

And here is a comparison of the five LROC-NAC images we have now:


Click to view attachment

My candidate is a dark spot which, in the best images may be resolved into a small crater. No bright halo, no lump casting a shadow. If it is Surveyor 4, it crashed. South of it at a distance of 200 m is a small dark spot which might be the retro-rocket.

To me this suggests scenario 3.

Phil

Looks compelling. Is it well within the intended landing ellipse? If there was a single thruster failure it may be offset from the projected course line.

Well within the ellipse which was about 30 km across, and in fact only about 1500 m from the location suggested by tracking.

Phil

Hmm. Sounds like a #2 splat is more probable, then. A #4 splat (total, near-simultaneous descent thruster system failure after retro jettison) might also explain it, esp. if they did fire for a bit but cut off prematurely, which would also explain the apparently very good targeting.

It would be so cool if some of those private company landings (Lunar Express, etc.) launching soon were targeted to this location to get the ground truth. Since they aren't scientific missions, they could play a part in solving some of these space age mysteries. It's a crash site already, so it's not like landing at the Apollo sites, which raises heritage issues...plus practicing precision landings is always a useful exercise!

There are probably more interesting targets! And remember this is only a suggestion, it might not be correct. A bigger splat like a Saturn SIVB stage impact might be more exciting to look at close up. Right now, though, most of the people who want to fly commercial missions are looking at doing science rather than just sightseeing. PTScientists are looking at landing in the Taurus-Littrow valley and inspecting the Apollo 17 rover, but other post-GLXP teams are focussed on science, hoping for a boost for future missions if they can demonstrate their technology works.

Phil

You could make the argument that these splats are worth scientific investigation, because they're likely to expose blocks of "fresher" rock from within the regolith or even solid crust (depending on penetration depth and what not). They're not in-situ, but you're also able to get a look at larger samples without having to grind away on them to get a fresh surface.

I saw your post on Surveyor 4 and dug up my old candidate files...
These are NAC images with illumination from West, Small incident, East , and Terminator (west)
The Object is at 0.407N, -1.3493W
It is probably a rock (sigh)
I forget how much I blew them up, but they are all the same scale (3x?)
anyway it's a nice little shadow casting object near the landing point...
here is a GIF ...

Click to view attachment

Going back a little, to the chat about LM impact images (and Post #384 by dvandorn about seismic detection)... they all came in at low incidence angles, quite unlike the SIVBs, hence the "smear" effect of tumbling debris in multiple dark streaks. Might this not produce a quite different seismic result than direct impacts from the virtually overhead descent of the SIVBs?

I’d like a possibility to be checked that I’ve found Luna 9 in LRO images.
Expected:
Two objects of different size, namely E6 descent stage and the Luna 9 probe, landed in the vicinity of 7.13 N 64.37 W according to the TASS report of 06 Feb 1966.
Found:
Two bright objects of different brightness, with long shadows, 130 meters apart, at approximately 7.02 N 64.33 W.
Positions:
M132071202LE
Larger one – Line=23370, Sample=1379
Smaller one – Line=23220, Sample=1645
See attached fragment (N at bottom, E at left)
M114376090RE
Larger one – Line=27910, Sample=3828
Smaller one – Line=28056, Sample=4073
M132071202LE
Smaller one – Line=23660, Sample=275
Larger one – off picture but a black scar (?) seen at L=23706, S=66
Cross-posted in Russian at http://novosti-kosmonavtiki.ru/forum/forum...255/?PAGEN_1=91

It's always interesting to see attempts to find one of the early Luna landers.

In this case, first, can you show with arrows which objects you think are the lander and the descent stage? There is one particularly large object but there are at least two smaller ones. (ADDED later: OK, I see you did that in the post on the Russian forum).

Second, the coordinates given at the time were not very reliable, with an uncertainty of about 30 km (1 degree on the Moon). The landing should be in an area within about 30 km of the stated position, not necessarily right there.

Third point - we don't have to rely only on looking for objects on the surface. Luna 9 took images which include a full 360 degree panorama showing about 200 degrees of the horizon (south, west and north of the lander). That horizon is flat, a point which I have argued for years to imply that the lander is not where the early reports said, near a range of 1000 m high hills, but must be far enough away that the hills are hidden below the local horizon. That local horizon could be a gentle ridge or degraded crater rim, so we can't just use the geometry of a featureless spherical moon to calculate a distance from the suggested point. Your coordinates are at the east end of the range of hills, and the western horizon from that location would not be flat. I personally prefer to look further north, maybe about 7.9 north, 64.2 west. But there is room for a lot of variation in those values.

And since we have images, a rough map of the landing site can be made and the pattern of craters can be compared with the LRO images. Now what we need is an object representing the lander, an object representing the descent stage, AND several craters with sizes and positions matching the lander images.

I will compare lander images and your LRO image in a later post. I do believe the search can be made successfully, but I don't think your identification is correct. I actually think Luna 13 will be easier to find than Luna 9 because the features seen in the distant landscape are clearer. For Luna 9 the distant landscape is down-sun and all washed out.

Phil

OK, here is a comparison of the suggested features with two versions of maps of the site.

1. The LRO image (rotated north-up) with two identified features, from the link in the previous post.
Click to view attachment

2. Shaded relief version (by me) of the original Soviet published map (from 'First Panoramas of the Lunar Surface').
Click to view attachment

3. A different interpretation of surface features, by me, derived from a reprojected panorama.
Click to view attachment


The differences between the two maps from Luna 9 images show how difficult it is to map the surface from a camera at such a low elevation above the surface.

I don't see any obvious matches.

Since we don't see the descent stage in the lander images, most likely it is east of the lander (or northeast or southeast), excluded from the tilted panorama. It might also lie west of the lander in an area in the foreground which was also not imaged.

Phil

Thank you Phil.
The Luna 9 maps show area some 15 meters in diameter; I'm not sure if these can be matched against LRO photos.
A 1967 description of Luna 9 say it rests in the western slope of a depression of 14-15 meters in diameter, hence the tilt to the east. Such a depression should probably have been visible.
Also, we should expect two fresh craters in the vicinity where two equipment sections crashed after separation at descent brake start.

May be this is the elusive Luna9 we are looking for?

May be this is the elusive Luna9 we are looking for? There is small mark from NorthWest (25m from where it would have landed & rolled off?)

The crater to the right is 6m in length
Landed near to a crater with diameter of 210-360m ( North of the landing spot there is a crater with length of 360m)
There is a SouthWest small Hill feature at a distance of 7.5 km(Not sure whether it will be visible)
LRO Images are from 0.44,0.52m resolutions

To the Southern Side is the feature next to Plantia Descencus (The height of is 600m & I am not sure whether they would be visible from a distance of 7.5km due to Moon's curvature)

That's quite a good match to nearby features, better than what I usually see. I have highlighted one object which I think should be very apparent in the images but is missing. I feel that the feature in the area of my 'crater E' should be more prominent.

I don't mean to be eternally negative, but this is a very difficult problem to solve and only the most convincing evidence is good enough.

It would be useful to know where this is. The issue of the mountains near the usually reported position has to be addressed. Shan had previously suggested a location in the hills south of the usual position but I didn't like the topography nearby which I felt would not allow a flat horizon to the south and west.

Phil

Click to view attachment

Sent you the co-ordinates in a message with links

Yes there is something visible as you said see the below images and One is the normalized without any zoom & another one is a zoomed in picture.. And also attached a Gif of the same area under different lighting conditions & the object lighting remains almost the same with darkness underneath due to soil disturbance?

There are some debris to the South East side but I don't see any craters ( The images I have attached here are 0.44m resolution)

The only thing I doubt is all the reports mention it should be on the western slope of a small depression so the tilt to east

Lat:7.506
Lon:295.508

https://quickmap.lroc.asu.edu/query?extent=...teQDeAvgLqlFmlA

Is the Western slope means the slope is from east to west? and the place where I am exactly showing is 2m below the surface

The lander is tilted so that its top is pointing towards the east. The image strip is looking down at the foreground on the east and up into the sky on the west - just catching he horizon at the bottom of the panorama. The trouble is, we don't know if that means it is sitting on a small rock or a crater wall. If it's a crater wall it is on the western inner wall of the crater so it faces towards the east - but there is no evidence in the image to say that is what it has to be. It could be on a small rock on otherwise level ground.

Your location is not very far from the hills to the south, and I think they should be visible in the southern part of the panorama. I would feel more comfortable being another 10 km north to get those hills below the horizon. The Soviet coordinates came with a big uncertainty, plus or minus about 15 km. An exact distance from a hill of any given height is difficult to state because the horizon could be formed by a local rise, not an ideal horizon on a smooth sphere.

The crash stage - the discarded landing rocket - should be visible nearby as well, substantially larger than the lander and probably mostly intact as it was also travelling at low speed.

I believe the previous picture might not be the luna9 landing site as the craters surrounding it are too large (They are nearly 10m in Size whereas from your pictures its supposed to be less than 1m or 2m in diameter)

And the most important thing I found out is the landing location of Luna13 is 440km from Luna9 (from Soviet sources & papers). If you calculate the distance between Luna9 (7.13, 295.63) and Luna13 (18.87, 297.95)..it comes to around only 390 kms.. so Luna9 might be have landed South of the intended landing site (If we find Luna 13 then we must be able to find Luna 9 sooner)

The process here reminds me to a fair extent of what I go through when I take pictures of a star field trying to locate a point object, such as a comet, quasar, dim star, or Pluto. Pluto is invariably surrounded by many brighter stars and so I must compare the stars in my image to the finder image. This is in principle not a challenge because a match always exists and can always be found, but in practice – an imperfect mount alignment combined with the time pressure of making sure my telescope is aligned in time to take longer-exposure images – it can turn into 30 minutes of high stress and I find myself doing almost exactly what you are doing in this thread here.

So I wonder about an algorithmic approach to solving this problem.

Of course, one big difference is that sky field images consist, essentially, of points of varying brightness, with pure black between them. The lunar map analog would be craters, and that's a strong but imperfect analog, with other variations in topography being part of the reality and hard to abstract into something that an algorithm would represent and handle well.

If there are enough outstanding mysteries to solve, it might be worth pursuing an algorithm to facilitate the process. Our eyes are wonderful at identifying patterns of many kinds, but aligning maps of star fields or of craters is not one of them.

I guess you're talking about plate solving - the process of automatically matching a star field image to a map. I could imagine applying plate solving software to matching a projected local lunar panorama to maps. Someone would need to identify craters and create an effective "star map", with the position of each "star" representing the crater location and the brightness of each "star" representing its size. Plate solvers incorporate tolerances that could take into account errors in the panorama due to topography etc. But that would be a huge amount of work unless it could be automated somehow.

Otherwise some more generic image matching might work, if maps and panoramas had similar lighting?

This problem is not really suitable for the kind of algorithm being suggested here. A problem that would be suitable would be trying to match a descent image taken by Chang'e 5 with an LRO image to locate the landing area. That's two overhead views. With Luna 9 we are looking at a very low angle oblique image (the camera was about 50 cm above the surface) and a restricted area of good coverage (looking down-sun there are no visible details, looking up-sun we are only seeing an area about 2 or 3 m wide as the camera was tilted down in that direction) and everywhere the image contains bad relief distortions. My reprojected Curiosity panoramas are much more amenable to comparison with a HiRISE image because of the higher viewpoint and 360 degree coverage, but even there we are helped by knowing pretty closely where to look (and I have made bad mistakes sometimes). For Luna 9 we could be looking anywhere within a circle 30 km in diameter (maybe a bit more).

Eventually it will be found. The LRO image will show the lander, the landing stage, maybe the air bag pieces, a brightened blast zone around the landing stage site, and several craters and rocks recognizable in the panorama. When it's found it will be immediately obvious, but until then we will just have rocks and craters in some vague semblance of the expected pattern.

I think Luna 13 will be easier to find because of a better view of middle distance features.

Phil

I believe Luna9 will be easier to find as the hill that is visible on the image might be the one that is to the east of Planitia Descensus and searching in and around the area found something like these.. but need to see what exactly they are those.. They might be the debris as they nearly match the distance the hills can be seen from the pics..

Phil whether the rocket stage impact of Luna9 would look similar to this? Not sure but this one has a diameter of 5~8m & irregular in shape (Whether a mass of 1400kg hitting at 22 km/hr would make such a impact?)..

I think if an object hits the surface at 22 km/h it would be damaged but it would still remain largely intact and would show up in the images as a single object. It would be similar to a large rock in appearance. it would probably not look like this, a crater with rays. To me this looks like a natural crater formed by a high speed impact. If it was the Luna 9 braking rocket stage the lander would be close to it and the pattern of craters visible around the lander in the panorama should be visible as well.

Phil

Not sure my 22 km/hr estimate was right because from here - https://nssdc.gsfc.nasa.gov/nmc/spacecraft/...d=1966-006A.The article says that capsule impacted at 22 km/hr and didn't mention anything about the rocket stage.

https://nssdc.gsfc.nasa.gov/nmc/spacecraft/...on?id=1965-044A - Luna8 one..

• At 48 seconds before the capsule velocity was at 9300 km/hr (2.6 km/s)
• Then main engine fired for 48 seconds from 75km to 250m
• At 250m 4 vernier engines with a thrust of 245N fires and slows down the vehicle further (A probe is released from the bottom of the spacecraft to measure the altitude)
• When probe makes contact with the ground..the capsule is ejected from top of the spacecraft (Whether it's the same one that has a lander or a different one)
• After the capsule was ejected it impacted at 22km/hr & then bounced off several times

Whether it would be possible to have the velocity reduced from 9300 km/hr to 22km/hr under 50 seconds by 45000N Engine from 75km altitude to 250m? I am not sure about the exact details but there might be more to it as the details when the probe was ejected are still a mystery..Luna8 page on NASA says a boom was released from the bottom of the spacecraft to check the altitude but the pnot sure whether Luna9 capsule was ejected when the spacecraft was hovering? and after ejection it seems the 4 Vernier engines were cut off which might have resulted in spacecraft crashing on to the surface. The only way to verify this is to look for an impact similar to this near Luna13.. (Wish we had more details)

Location : https://quickmap.lroc.asu.edu/query?extent=...AyAbwF8BdC0yioA (Lat: 7.37233 Lon: 295.26334) - The small crater is about 4~5m in size..This might be even Luna8

if this is Luna9 rocket stage impact then Luna9 might be lying to North west of the impact point and the area also has depression from West to East..

@Phil - Luna9 might have landed to further east of

From 3D model of the area, I believe the hill we are seeing SW at 240 degrees is the one to the left of Planitia Descensus. Luna9 might have landed between 7.20-7.50N and 296-297E (It might have been possibly inside the crater or an area that obscured Planitia Descensus with the hill to the right of Planitia Descensus being visible)

http://target.lroc.asu.edu/qm3d/o2w_3d_815...10_0_100_101_0/

@Phil

Whether this could be one of the Luna9's Debris? Are we looking for something similar to this?

The 2nd picture is comparison of 3 different LRO images side by side

It is a nice candidate. The landing stage should be visible somewhere nearby, and could possibly be the object in a small crater WNW of the 'lander' object, and larger than the lander. I would be happier if the crater SE of the lander in the panorama was more visible here, and if the area around the putative landing stage was brighter. So far, though, I would say this is the best candidate I have seen.

Can you show us where this is?

Phil

Here is the location - https://quickmap.lroc.asu.edu/layers?extent...bREONLRfImq7ioA

Lat:7.42075
Long:296.93447

I am not sure exactly whether this is the landing stage or we are looking at Luna9 itself. There are objects to NorthWest and SouthWest of this region looking liking debris but it's hard to tell..Will search more on the surrounding area..

Probably the best thread to post this (mods, please move if the LROC thread is better) It appears that DSCOVR'S second stage will be impacting the moon in a little over a month (far side):
https://www.projectpluto.com/temp/dscovr.htm
The chances of witnessing the impact by orbiters is tough, but a very fresh crater should have some scientific value (and the first ever unintentional impact, at least that has been precisely calculated).

Thanks for pointing that out! Another point on the map.

Phil

Shan, that location is quite far east of where we might expect Luna 9 to be. I think the Soviet idea of uncertainty for this site was about 30 km and this would be right on the outer edge of that or even a bit beyond it. It's not impossible but I would be happier if it was further west.

Phil

Phil, These might be the side modules which got jettisoned before landing and also there is another similar rocket plume marks to the North East of the region (Both got jettisoned about 74km from the surface)

https://quickmap.lroc.asu.edu/query?extent=...AyAbwF8BdC0yioA

I believe it's somewhere to the east of the region but need to look into those.. or in that area itself..as that hill would be still visible from that area, but I need to keep looking into it..

Some more estimates in this article, including a map of dispersions: https://www.space.com/spacex-falcon-9-moon-...-one-month-away

North of Mare Orientale, so still a chance of impact on on the near side, depending on the solar pressure, other noise (and also lunar libration).

Unexpected turn of events... it's not the DSCOVR upper stage, it belongs to the Chinese Chang'e 5-T1 mission launched slightly earlier than DSCOVR.

https://arstechnica.com/science/2022/02/act...o-hit-the-moon/

Don't worry, we still get a crash!

Phil

Fascinating... I wonder where DSCOVR s upper stage went, then!

How different are the empty masses of the upper stages, for comparison, since the crater produced might be a bit different too?