It happened March 19, 2008.

The optical afterglow was 2.5 million times more luminous than the most luminous supernova ever recorded, making it the most intrinsically bright object ever observed by humans in the universe. It was so bright that immediately after the blast, Swift’s UltraViolet and Optical Telescope and X-Ray Telescope indicated they were effectively blinded, originally leading researchers to think something had gone wrong.

"For a few precious seconds, the luminosity was a million times that of the whole galaxy," explains Dieter Hartmann, a Professor at Clemson University.

And on top of that, the burst shattered the record for the farthest object that’s ever been visible to the naked eye. The previous record was a spiral galaxy called M33, which is thousands of times closer than the March 19 explosion.

The explosion, which took place halfway across the universe, was so far away that it took its light 7.5 billion years to reach the Earth. In fact, the explosion took place so long ago that neither the Earth nor the Sun had come into existence.

To top it off, it was a supernova-collapsing, planet-destroying, blackhole-creating gamma-ray burst. Here’s Bad Astronomy:

A GRB is born in the fury of an exploding massive star, when its core collapses into a black hole. A vast amount of energy is released, more than the Sun’s entire lifetime’s output. A hellish mix of forces focuses, squeezes this exploding energy and matter into beams, extremely narrow cones of emission, cosmic blowtorches which march across space. If you are too close, and in the path of a beam, well, saying "you’re toast" doesn’t quite cover it. But if the beam misses you, you don’t get the gigantic burst of light; the energy drops of very rapidly if the aim of the GRB is off. Even a miss by a fraction of a degree is enough to change its apparent brightness hugely.