JASE and All,
Indeed, this is a big fan. Rather spectacular, while puzzling, development!
What has struck me even more than the fan in this image is the
shapes that can be seen on the cave's walls. There is two rocky, smooth, O-ring shaped circles in those walls, one that seems to be aligned with the fan and one, less visible, a few yards behind it.
What kind of "tool" would be needed to create such shapes in solid rock?
Some type of unknown laser beam technology?
Hard to imagine such an Alien tool!
Could this tool also be used as a...
...weapon?
=(
Macmarts