Extricating Spirit, Digging out from Troy Options

[briv1016]

5 downsampled navcam frames from sol 2078 are down. Someone might want to make an animation.

[imipak]

I don't remember seeing any estimates of how far back along her path Spirit needs to move to have all five working wheels on solid ground. Does the thin crust over the bright, dusty material extend further back than the visible piles of powder excavated by the left hand wheels?

And - forgive me if this has been answered, I've searched but not been found it - do we know what the pale material actually is? Silica or sulphate salts, or something else?

(Edit: Found CosmicRocker / Paolo :

http://www.unmannedspaceflight.com/index.p...;p=142244"]http://www.unmannedspaceflight.com/index.p...st&p=142244

...which doesn't shed much light )