The most massive black hole in the universe tips the cosmic scales at 18 billion times more massive than the sun, astronomers suggest today at a meeting of the American Astronomical Society. Even though researchers suggested black holes up to this mass might exist in quasars, this is the first direct confirmation of such a behemoth. The hefty gravity well is six times more massive than the previous record and is orbited by a smaller black hole, which allowed the measurement of the giant's mass.