Animation depicting the birth of a quasar, seen from a distant planetary system. A quasar is a type of highly energetic active galactic nucleus AGN, and they are the most luminous objects known. Their active nuclei are thought to be powered by matter in an accretion disc around a supermassive black hole at the galaxy磗 centre. The gravitational force accelerates the infalling matter, causing it to emit radiation. The process can switch on and off depending on the availability of matter near the black hole. Quasars and other AGNs often show bipolar jets, streams of matter and energy directed away from the black hole磗 poles. One such jet is directed straight at the planet here.