Context is everything. Hi-res images of Mars's mountains and landscapes are all very impressive, but this shot of Curiosity's wheels really drives home the fact that we've got a robot romping around on an alien planet. Mars has never seemed so close.
This image also reminds us how big Curiosity really is. Each of its six wheels measures a half-meter across, about 1.6 feet. The rover is currently making the rounds in Yellowknife Bay.
Image: NASA, JPL-Caltech, MSSS, MAHLI.