In the field of planet hunting, Geoff Marcy is a star. After all, the astronomer at the University of California, Berkeley found nearly three-quarters of the first 100 planets discovered outside our solar system. But with the hobbled planet-hunting Kepler telescope having just about reached the end of its useful life and reams of data from the mission still left uninvestigated, Marcy began looking in June for more than just new planets. He is sifting through the data to find alien spacecraft passing in front of distant stars.