Astronomers have made the unexpected discovery of two black holes inside an ancient cluster of stars in our galaxy, the Milky Way.
The research, published today in the prestigious journal Nature, describes the detection of two black holes that are about 10 to 20 times heavier than our Sun in the globular cluster named M22.
Black holes, so dense that even light can't escape them, are what is left when a massive star reaches the end of its life and collapses in on itself.