Just a brief post to highlight a cool image. Several of us over at unmannedspaceflight.com noticed that the pretty peaks of the eastern rim of Gale crater suddenly disappeared from Curiosity's view a couple of days ago. Egorov Vitaliy put together this little animation that documents the changes. There's nothing surprising about changes in the atmospheric opacity; Mars' dust is very easy to lift into the atmosphere, so changes in atmospheric opacity happen with every variation in the winds. It strikes me that if you lived on Mars, dust opacity would be part of your morning weather report, like humidity is for us Earthlings.
NASA / JPL / Egorov Vitaly ("Zelenyikot")
Changing atmospheric opacity in Gale crater, sols 59 through 101
Six Navcam images pointed toward the horizon taken over the course of Curiosity's time near Rocknest document changes in the transparency of the atmosphere.