“The Source a Mystery” –Ancient Rivers Ran Through Mars

  Mars is crisscrossed with the distinctive tracks of big, long-dead rivers but we still don’t know what kind of weather fed them. Scientists aren’t sure, because their understanding of the Martian climate billions of years ago remains incomplete. NASA’s spacecraft have taken photos of hundreds of these rivers from orbit, and when the Mars … Continue reading “The Source a Mystery” –Ancient Rivers Ran Through Mars