I think they picked this crater because it exposes base rock.................
They picked this particular crater because pictures from the Mars orbiter clearly showed that this crater was once a lake with a river that filled it, and a river that maintained the water level. If they can’t find some manner of fossil there, it’s dead Jim and always was.
What’s crazy about Mars is I never realized how incredibly far it is from earth. I read something once that said if you could drive there going 100 mph 24 hours a day it would take 4 HUNDRED years to get there!! That’s unreal, if you left in the year 1621 around the time the pilgrims landed at Plymouth rock, you’d be hitting Mars about now