[cabojoe]

Cave entrance on the flank of Arsia Mons At its highest resolution of 25 centimeters per pixel, the HiRISE camera can see the detailed shape of the slightly scalloped edge of a hole on the flank of Mars' Arsia Mons (left), but no amount of image enhancement (right) can bring out any further details inside the hole. That means that the walls of the cave are overhanging -- the cave is larger below the ground than the entrance we can see at the surface -- and that it is very deep. Mars' dusty atmosphere produces enough scattered light that "skylight" would illuminate the floor of a shallow cavern well enough for HiRISE to detect it. Credit: NASA / JPL / U. Arizona

[Lancey Howard]

That is a very round hole, and no doubt it was perfectly round at one time, shortly after the mighty launch of a spacecraft of obviously huge proportions which carried the survivors of the great Martian apocalypse. I wonder where they went?

[Renfield]

This looks like a bullet hole in a piece of blotter paper.

As far as I know, the Planetary Society is a legitimate organization, but I sure am suspicious of this photo. It makes the surface of mars look as thin as an eggshell.

[Cricket24]

I don’t know. It looks like a black spot on the picture! It seems that it’s too perfectly round. Just a glitch with the camera?

[MHGinTN]

Suspicious ...looks more like a touch up job to blot out something the public is not supposed to see. Look along the left edge of the enhanced ... OTH a solidified then indented pool of oil would allow for the same effect of light absorption, wouldn’t it?

[Tolsti]

Watch out for these:

[Brilliant]

I would say that a very energetic asteroid made that hole.

[Hot Tabasco]

Looking at that close-up, that could very well be uranus.....

[GregoryFul]

Not just one, but seven of these odd pretty round “holes” have been imaged. I wonder if they are all the same size?

[Covenantor]

So that's where all the Iraqi oil went. Does Rosie know this yet?

[Ruy Dias de Bivar]

Don't look too close!