Mars Rover Finds Ancient Streambed Proof of Flowing Water

Adding a scale to the pictures might have been useful.

Agreed. Found this on the NASA site:

Thanks, John.

I just had a mental image of the rover arm holding an old engineering ruler next to the camera.

Ha!

I've just split my sides thinking of all sorts of possibilities ! Imagine mission control seeing some articulated arm curling around and giving them the finger, a polystyrene burger box fluttering across the field of view. There's a goldmine of 'things you never expected to see' in this one. Rover goes rogue - I love the notion .