wow, i guess it was a cave (could there be caves on the moon?) that was hit by a meteorite then..
Originally posted by Romanian
wow, i guess it was a cave (could there be caves on the moon?) that was hit by a meteorite then..
[..] scientists say, the unusually proportioned feature is most likely a portal into an underground cavern that once held flowing lava.
The feature is likely what geologists refer to as a skylight, or collapsed portion of the roof of an underground tube that once held flowing lava, van der Bogert and her colleagues propose. If that’s true, the skylight is the first such portal spotted on the moon.

That hole is where the Selenites had their Solar lense - to focus Sun light onto their crystal sphere below, for power. The lense was broken out
when Joseph Cavor's Cavorite sphere-ship broke through it, to return to Earth. I guess the Selenites never repaired it.