When astronomers discovered a strange pattern of light near a distant star called KIC 8462852 back in October, it was like nothing anyone had observed before. When a planet passes in front of star, the star’s brightness usually dips by around 1 percent, but KIC 8462852 has been experiencing dips of up to 22 percent, suggesting that something huge is zooming past. And now a second star with strange dips in brightness has been identified. Named EPIC 204278916, the star is estimated to be about the size of our Sun in diameter, but has only half its mass. It was...