“Wanted: Amateur star-gazers and Star Trek fans interested in exploring planets outside this solar system. Must be open to the possibility of life beyond Earth. Knowledge of Klingon not necessary. Sense of humor a plus. So might read the description for Andrew West’s MOOC–massive open online course–called Alien Worlds: The Science of Exoplanet Discovery and Characterization. The course launches on Friday, October 31, and more than 4,870 people have already registered. More are welcome to join.”