A Medieval Monk Beat Halley by 700 Years!

A clever monk named Eilmer spotted the same comet twice—in 989 and again in 1066—and figured out it was the same space rock coming back! Nobody knew comets could return before this, so Eilmer should probably get the credit instead of Edmond Halley, who made the same discovery way later. Now scientists are wondering if we should call it Eilmer's Comet instead!