S When you look into the heart of the Crab Nebula, you are staring at the gamma-radiation-soaked nightmare of history. You may have already known that this gorgeous nebula is the result of a supernova that Chinese and Arab astronomers recorded back in 1054. But what you didn't know is that the dead star became a pulsar that's still pouring ultrahot, oscillating gamma radiation out into the cosmos. Researchers in the U.K. are investigating this gamma-spewing pulsar, and Clara Moskowitz has the story at Space.com. Image credit: NASA/ESA and Jeff Hester (Arizona State University).