Submission + - Spelunking the caves of Mars
OriginalArlen writes: After earlier images caught glimpses of mysterious cave openings on flanks of the Martian volcano Arsia Montes, the MRO's superb HiRISE camera has now captured amazing close-up images of this cave / "skylight" on Arsia Montest. How big is the cavern below? What does it look like inside? Somehow I doubt we'll get data from inside in my lifetime, so let the wild-eyed speculation begin!