Renegade Black Hole
There was a lot of panic that booting up the Large Hadron Collider would cause a man-made black hole to form, sucking all matter and energy in our solar system into it. That didn’t happen, obviously, but celestial vacuums are still something to worry about. The closest known black hole is about 159 quadrillion miles away, so it doesn’t pose a threat to us, but scientists just discovered something new: roaming black holes. These actually move through space, leaving a trail of gravitational destruction behind them. If one got even a billion miles away from Earth, it would be enough to change our orbit around the Sun. Any closer and it could actually suck us in beyond the event horizon.