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

[Phil Stooke]

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.

[Shan]

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)

[JRehling]

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.

[fredk]

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?

[Phil Stooke]

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

[Shan]

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..

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[Shan]

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

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?)..

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[Phil Stooke]

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

[Shan]

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..

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[Shan]

@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/

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[Shan]

@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

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[Phil Stooke]

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

[Shan]

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..

[Explorer1]

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).

[Phil Stooke]

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

Phil