A black hole deep in the cosmos, some 5 billion light-years away, could be the most massive ever found.The galaxy SDSS J1148+1930 harbors a behemoth, around 36.3 billion times the mass of our Sun.This newly discovered black hole no longer fits within the category of supermassive – the giant beast of a thing is ultramassive.The discovery was made using a rare cosmic alignment called a gravitational lens, which allowed the researchers to determine the mass of the black hole.The black hole is located in a fossil galaxy, which is a single, massive blob of a galaxy that was once a galaxy cluster.The researchers believe that, over time, the galaxies in the cluster – each with a supermassive black hole in its center – merged, their black holes also eventually glomming into one big 36 billion solar mass black hole.This discovery provides a huge clue about one of the Universe's many open questions: how supermassive black holes get so enormous.