From a hole in the ground, to one in space, it's all a mystery

Just about every news organization across the planet carried the first-ever image taken of a black hole last week. And the photo, captured by the Event Horizon Telescope, a global array of eight ground-based radio telescopes, was literally out of this world.

The image, which emerged from joint efforts by more than 200 astronomers worldwide, including 16 from the Chinese mainland, offered up the first visible representation of what are generally considered to be the most extreme objects in the universe.

The photo depicts the black hole at the heart of Messier 87, a galaxy some 55 million light-years away from Earth, that has a mass 6.5 billion times greater than the sun.