[swombat]

It's pretty high-contrast, though. Presumably an algorithm could find interesting high-contrast, high-symmetry structures quite easily...

[ojilles]

This image is probably not the resolution all of Mars got imaged at, right?

[Arelius]

I don't have the tools on this CPU to get good numbers, but if that hole is about 35 Meters, I'd estimate to resolution to be about 20 CM/Pixel. I know it's often difficult to find civilian access to Imagery at a better resolution than 5 M/Pixel for some places on Earth.

It's probably safe to assume we don't have imagery this good for the entire surface of Mars.

Edit: It seems likely that these new images are captured with this equipment: http://en.wikipedia.org/wiki/HiRISE