NASA reveals finalists for next New Frontiers robotic mission: Saturn's moon Titan or Rosetta spacecraft's comet

The field for NASA’s next New Frontiers mission is narrowing. Officials announced the two finalists for a new robotic explorer mission — one that would send a spacecraft to bring samples of the comet 67P/Churyumov-Gerasimenko to Earth, and another to explore Saturn’s moon Titan.

The two mission...