4 comments

• J Fincannon

  January 23, 2018 at 7:47 am

  Bob,
  Do you really think those claimed “skylights” are real? I looked at all LRO NAC images of those features. They do not lead me to think they are anything but a crater with a shadow in it. I can find lots of those. The reason I think you will likely not be able to find any skylights at the latitudes closer to the pole (using imagery) is due to the lousy Sun angle. At this particular site, the sun angle never goes above 19 degrees above the horizon and this is when the Sun is due south. The rest of the day period it is even lower elevation. You need a higher Sun to see into presumed “skylights”.

  Dr. Spudis raises a number of good points especially how you do not really need lava tubes for a base especially near the poles.

  So, I am inclined to interpret the story about these “polar” lava tubes/skylights to be hype and must be taken with a grain of salt.
• Robert Zimmerman

  January 23, 2018 at 8:41 am

  J Fincannon: I recognize totally all the uncertainties here. I spent a lot of time looking very closely at the images, and came away with some doubt about whether they were skylights. At the same time, to my eye these particular dark spots appeared different than mere shadows. In addition, the work you and I did inspecting the floor of Copernicus demonstrated to me that skylights and lava-type tubes can exist in the floor of a crater.
• Cotour

  January 23, 2018 at 9:09 am

  Q’s: How big are these caves estimated to be / how big do they need to be? And more importantly, how stable might they be? (Are they lava tubes and if they are will they be naturally stable because of how they were created?) And how is it suggested that the interiors of these spaces be structurally stabilized, if need be, so as to be relatively safe space’s?

  Is there any way to competently answer these questions without actually getting there in person?
• J Fincannon

  January 23, 2018 at 9:55 am

  >At the same time, to my eye these particular dark spots appeared different than mere shadows.

  Really? Look around the entire Philolaus crater and you find a lot of little craters with the same shadow.

  >In addition, the work you and I did inspecting the floor of Copernicus demonstrated to me that skylights and lava-type tubes can exist in the floor of a crater.

  Yes, they can exist, but I feel that the authors of the press release needed a lot more proof before making their claims. I can point out a lot of “skylights” at the higher latitudes (thousands I dare say), but without proof, it is just speculation and hype. I say it is impossible to confirm them without something like orbiting radar data (or going there with a rover). The LOLA (laser data) is not good enough because of the poor point density. If they had some clever dataset like thermal data at high enough resolution (which also does not exist), then maybe I would be impressed, but no, they just used the “best” LRO image they had which although at the highest Sun elevation, was not enough to show any more than the typical crater wall.