I've seen plenty of things on the rover pics that have never really been explained. There were bits of pieces of something lying on the dust in the 360 pan view, one of which looked like a skull with antlers. I know it's not, and most likely it's part of the lander, but I wish NASA would say something about these things! Same with ESA and its green patches and the dark blue deposit in some deep gully. None of this was even mentioned.
As for the bright stuff in the track, I'm at a loss. If I didn't know better I'd say it was chalk in that pic - but earlier landers have tested the dust and there is no chemical evidence for it. Its not life because that dust is obviously very dry. It may be some kind of powdery mineral deposit such as silica. But why is it only a few cm down? Why is none on the surface??
