Like any spiral galaxy, M106 has a pair of arms full of bright young stars (green), but researchers have long wondered at the source of its two extra arms (purple and blue), visible in radio and X-ray images. Now they think they know. Using archival data from four NASA and ESA space observatories, they measured the gas temperature and X-ray absorption of the so-called anomalous arms, which suggest they are heated by shock waves from twin jets of particles streaming from the supermassive black hole at M106's core. Their report is scheduled for publication May 10 in The Astrophysical Journal.