I'm no trained scientist, but I bet that Opportunity is indeed at the site of what was once a salty sea that has since evaporated away, leaving salt (and whatever else) galore. What I wouldn't give to have been on Mars a few million years (or however long) ago.. but now, I can only imagine, which maybe is better, who knows. Cough up your secrets, Mars, and cough them up now!

Possibly this dunes riding give a good clue about the internal structur of these dunes. My first guess is that they don't shift or only very slow. Perhaps each time there is a sandstorm the dunes gets a little changing, or in better words, cumulates some matter and after the hard solar radiation acts in a manner that give this cohesion.

I wonder if it might make sense - if they get much bigger - to direct blind-drives straight down the middle of these - to save the effort of clambering across them.

Perhaps they could drive accurately enough to drive on the western side of a dune - so as to give a favourable western tilt during the afternoon for better solar power - and then shift that to the other side at the end of the drive for a better power budget the following morning

Doug

The wheel swivels do look intentional, but the drivers could not have reacted in real-time quickly enough. This has to be a side-effect of the auto-nav program-- the Navcams (and other sensors) detect a tilt in Oppy when there is no boulder imaged in the path and it goes through several backup-turn-backup-turn cycles and moves on. I've not noticed, have we seen other examples of this while driving over these dunes?


Tweaking of the autonav programming may take care of this, but she may have to end up driving parallel to the dune and then shifting over periodically to keep the proper average heading. Much like "tacking" on a sailboat.

--Bill

Spirit did this once near Middle Ground - shuffle back and forward quite a lot. It saw a big rock and got scared.

Perhaps Oppy is identifying the ridge of each dune as a hazard of sorts.

Doug