"Discoveries like this really open our eyes to the fact that we are still uncovering mysteries and exploring wonders in the universe..."

The event was spotted in infrared data — also a first — suggesting further searches in this band could turn up more such bursts.

We ask Avi Loeb, founding director of Harvard’s Black Hole Initiative, to help us picture the scariest void in the universe.

"The question of the nature of dark energy is perhaps the most important unanswered question in contemporary physics...."

Astronomers have found that mysterious dark energy may originate in black holes.

"Relatively few dual black holes like this have ever been confirmed. This pair has the closest separation yet measured..."

Researchers have created millions of simulated galaxies to find out how black holes grow with their galaxies.

Gamma-ray bursts occur when a massive star explodes or when two neutron stars merge. A newly discovered burst has puzzled astronomers, as it lasted much longer than astronomers would have expected.

Current measurements of black holes are not enough to nail down how the invisible giants form in the universe, researchers say.