Lunar shadowed areas becoming revealed.

[3488]

NASA's MINI RF aboard the LRO & the MINI SAR aboard ISRO's Chandrayaan 1 in orbit around the moon are imaging the permanently shadowed areas in the moon's polar regions, where temperatures remain at approx minus 223 Celsius.

Below, the 42 KM wide Rozdestvensky K Crater 82.7 North 144.6 West near the lunar north pole on the far side as seen by the MINI SAR on Chandrayaan 1.
Major slumping within the permanently shadowed area is very apparent.

58 KM wide Sylvester Crater near the lunar north pole. 82.7 North, 79.6 West.
Large Image

10 KM wide north polar Erlanger Crater. 87 North 28.6 East.
Large Image.

Normal LRO LROC NAC image of the 10 KM north polar crater Erlanger. 87 North 28.6 East.
Large Image.

Andrew Brown.

 

[neuvik]

Haha, cool thing about that RF imaging is the picture created already looks like the lunar surface. Not much need for digital editing I should think. Still its amazingly crisp, nice images and thanks for the info Andrew!

Chandrayaan is approaching the end of its first year of its two year mission. Happy its is doing well! I heard though, that they are going to stop mapping at the end of its first year. Is that true? Something to do with the intense logistics and tracking it needs.

 

[silylene]

Erlanger, Sylvester N and Peary and several of the unnamed smaller craters look very cone-shaped (almost like the craters on Hyperion), and unlike lunar craters in the sunlit regions. Is this an artifact of the imaging process?

 

[Boris_Badenov]

Are there any theories on what caused that slumping in Rozdestvensky K Crater? It looks unusual & might be something of great interest (water Ice?).

 

[3488]

Thank you neuvik, silylene & Boris for you input here. :mrgreen:

I am pleased to see that people are interested in this, I absolutley love this sort of thing. :mrgreen: :mrgreen:

Hi neuvik,

Yes AFAIK Chandrayaan 1 is completing the lunar mapping cycle at the end of Year 1. Year 2 will be devoted to targetted obvervation of features of added interest. The mission will enter a new phase, it is not being wound down, if anything it will become even more scientifically interesting if anything.

Hi silylene,

I suspect it is an artifact of how the returned signal is received by the orbiting receiver. You are certainly correct regarding the Saturn moon Hyperion with the deep drilled down conical craters. We now know, that Hyperion is the least dense 'solid' body known in the Solar System at only 0.55 gcm3 (grams per cubic centimetre), barely over half that of coherent water ice.

Ice rich lunar regolith may behave in a similar fashion perhaps??? An interesting thought. What would need to be doen is for those SAR (Synthetic Aperture Radar) observations to be repeated but with either Chandrayaan or LRO passing over in a differnt direction. If the conical structure remains & is oritated the same way as in these images, then we can be sure that the conical shape is real. If not, than it's an artifact. The features shown on the crater floors are real, but it's how they are presented is probably due to artifacts.

Hi Boris,

Yes that grabbed my attention as well. That slumping is major. Itg looks like to me that the material was very fine. If it was denser, it would still slump but not pile up like that. To me fine material slumped, & collided with itself on the crater floor, creating that folded appearance. Could be explained by ice rich regolith, that would certainly fit with what we are seeing on the shadowed floor of Rozdestvensky K Crater.

There is also this, an LRO Mini RF (Mini Radio Frequency) radar strip of an 12 KM wide, 100 KM long area close to the lunar south pole.

Also lets not forget this incredible piece of work carried out by JAXA with Kaguya / Selene, a very long exposure of the 19 KM wide south polar Shackleton Crater. The long exposure by the Terrain Camera, captured very weak reflected sunlight from the upper rim, very, very faintly illuminating the permanently shadowed floor, some 3,300 metres deep. I have put a formal suggestion to the Mercury MESSENGER team to attempt this at Mercury with the shadowed terrain on mercury, which they have accepted & have suggested likewise with Shackleton Crater & other polar lunar craters to the LRO team.

19 KM Shackleton Crater long exposure Kaguya / Selene. X marks the Lunar South Pole.

As above but with cropped & enlarged portion showing the permanently shadowed floor of Shackleton Crater by Kaguya / Selene.

Normal shot of Shackleton Crater from the ESA Smart 1 craft.

Andrew Brown.

 

[kelvinzero]

Those artifacts do look like they are aligned with the strips. Could it be that the images are taken at a steep angle and just layed out to look flat? Could these craters look different because they are less likely to have flooded with larva than low land craters? (just testing my amateur observation skills )

 

[neuvik]

Those artifacts do look like they are aligned with the strips. Could it be that the images are taken at a steep angle and just layed out to look flat? Could these craters look different because they are less likely to have flooded with larva than low land craters? (just testing my amateur observation skills )

Oh no, not horrible Moon Larva! Hehe. I would think lava would be more apt to shape the craters in such a way. But those impacts were probably many decades after the moon had any flowing lava. Regolith liqification from impact probably doesn't have any changes in cooling time from the sub polar regions to the polar regions.

Heres hoping its expanding and contracting water causing the odd crater features though!

 

[silylene]

Andrew, I agree, it is likely that the cone shaped craters are an artifact of the imaging process. But I'd like to know for sure, if that is correct. If they are cone shaped, I think that may imply that the regolith at the pole has a different less dense composition (which has other more interesting implications).