When they do the color correction I swear you could just walk around up there. Looks like Nevada.
Also as smart as the engineers at NASA are (Lots of respect here) you would think they would have used a better material than aluminum for the wheels. I mean honestly that was a dumb choice. Titanium or even 1080 carbon steel (heavy I know) would have been a far better choice. I mean 1 ton stilling on paper thin aluminum? Not smart.
I was with a team of engineers at school who were designing a lunar rover prototype. The reason they gave for aluminum was three fold. It deforms much easier than other metals, it forms a protective layer during oxidization, and the weight is low.
Deformation makes traveling over uneven surfaces much easier. The shaped treads are able to elasticaly deform around the surface, and scale surfaces that would otherwise only allow the wheels to spin on.
Oxidization prevents pretty much any ferric materials from being used. The whole "red planet" moniker isn't for nothing. Carbon steels would oxidize too fast, and stainless steels are far too heavy. Utilizing titanium is tricky. Titanium tends to oxidize in a rather funny way, and produce some stunningly colored metal. If you have time, check out the forced oxidization projects, which can produce a rainbow of colors. All you need is an acidic solution and a controlled amperage.
Low weight is a huge concern in the rover. Titanium sounds great on paper, being that it is stronger than steel and significantly less dense. The part that is often forgotten is that aluminum and its alloys are nearly half as dense as titanium. That kind of weight reduction yields a significantly less robust wheel, but at almost half the mass you can actually afford to send it into space. Each pound counts.
Again, focusing on the small amount mass that can be blasted to the red planet, that "paper thin" aluminum makes us squishy humans look pretty fragile by comparison. It's less than that thickness of aluminum which skins the wings on passenger planes, which generate enough lift at take-off to carry several tons of aircraft into the sky. The steel mesh that you load lawn mowers onto (assuming you've got a trailer) is only 0.101 inches wide by 0.068 inches thick, and it isn't even a solid. Engineers for NASA are good at pushing the envelope. Occasionally this backfires...fill in your own jokes about metric to imperial conversions here.. but more often than not we get to see something truly amazing.