Red Planet or Bust? Nat Geo's 'Mars' Finale Takes a Sharp Twist

National Geographic's "Mars" TV series is coming to an end with the sixth and final episode airing tonight. The fate of the fictional Mars colony and the future of human space exploration are on the line after a major disaster on the Red Planet. In last week's episode, titled "Darkest Days," the Mars colonists suffered a devastating loss that could mean the end of the mission after four years of building a home on the Red Planet.