Almost but not quite in time for Halloween, astronomers announced Friday that they had discovered the closest known black hole. It is a biggie, a shell of yawning emptiness 10 times as massive as the sun, orbiting as far from its own star as the Earth is from ours.
Not to worry, however: This black hole is 1,600 light-years away, in the constellation Ophiuchus; the next nearest known black hole is about 3,000 light-years away in the constellation Monoceros. What sets this new black hole apart from the 20 or so others already identified in our Milky Way galaxy, besides its proximity, is that it isn’t doing anything — not drawing the nearby star to its doom, not gravitationally consuming everything nearby. Rather, the black hole is dormant, a silent killer waiting for the currents of space to feed it.