Stuck in the sand and with time to spare, Spirit hits the jackpot.
Analysis of soil samples from where the Mars rover Spirit is stuck shows evidence of subsurface water.
The sand is stacked with less soluble compounds at the surface and increasingly more soluble minerals farther down.
The finding is a fluke. Scientists added the research after the rover got stuck and engineers were trying to figure out how it could extricate itself.
Stuck in the sands of Mars, the grounded Spirit rover unearthed evidence of subsurface water in the planet's recent past.
"It's total serendipity," Washington University planetary scientist Ray Arvidson told Discovery News. "We're driving backwards, the right front wheel doesn't work, so wherever we went we had to drag it along. It's like pushing a shopping cart with a bad front wheel. You don't push it, you pull it, but the wheel has torque."
The rover ended up getting stuck, breaking through the crust and -- surprisingly -- discovering telltale byproducts of water passing through the exceptionally silica-rich patch of soil.