Explanation:
Landing
on Mars in January, NASA's twin rovers Spirit and
Opportunity have now each spent over 330
solsroving
the martian surface.
Still healthy and well in to extended missions, the
golfcart sizedrobots
have operated five times longer than planned.
Ranging
across the floor of Gusev crater,
the Spirit rover has reached the
Columbia Hills
and journeyed nearly four kilometers.
Half a planet away, Opportunity has spent much of
its tour
on Meridiani Planum
exploring the 130 meter wide
Endurance Crater.
Opportunity recently returned
this panoramic view
of rock outcrops and steep crater walls.
Both
rovers have uncovered
strong
evidence that ancient salty
oceans left their mark on the alluring
Red Planet.
