Sarah Kaplan, writing for the Washington Post: NASA's newest mission will either land a quadcopter-like spacecraft on the surface of Saturn's moon Titan or collect a sample from the nucleus of a comet. (Editor's note: the link may be paywalled; alternative source.) The two proposals were selected from a group of 12 submitted to the New Frontiers program, which supports mid-level planetary science missions. The first, called Dragonfly, would be an unprecedented project to send a flying robot to an alien moon. Equipped with instruments capable of identifying large organic molecules, the quadcopter would be able to fly to multiple locations hundreds of miles apart to study the landscape on Titan. This large, cold moon of Saturn features a thick atmosphere and lakes and rivers of liquid methane, and scientists believe that a watery ocean may lurk beneath its frozen crust. [...] The Comet Astrobiology Exploration SAmple Return, or CAESAR, mission would circle back to the comet 67P/Churyumov-Gerasimenko, which was visited by the European Space Agency's Rosetta spacecraft from 2014 to 2016. After rendezvousing with the Mount Fuji-size space rock, CAESAR would suck up a sample from its surface and send it back to Earth, where it would arrive in November 2038 (mark your calendars!).