Scientists have been pondering that question for decades—and now we know the fascinating answer: From the collision of two neutron stars 200 million years ago.

The collision sent a ripple through space that was observed early Sunday morning by the Laser Interferometer Gravitational-Wave Observatory (LIGO), the scientific collective whose founders won the Nobel Prize in Physics earlier this month. The group announced that event has revealed the origin of some of the heaviest elements on the periodic table. Included in that list: gold, platinum, and iodine—which is essential for human life.

But the truly exciting thing about the discovery, explains Duncan Brown, a LIGO member and a Syracuse University physicist at the heart of this discovery, is that it provides clues about the origin of the universe and the structure of matter. “This is a major advancement in human knowledge,” he tells Fortune.

Brown believes the neutron star collision may also help shed light on the prevailing theory of the formation of the universe—colloquially known as the “Big Bang” theory: That all matter was once collected into a single incredibly dense point and that that point “exploded” about 13,600 million years ago, creating the universe as we know it.

One of the key ways in which scientists have been trying to learn more about the Big Bang is by observing other explosions and collisions of celestial objects. Until now, LIGO had observed only four such collisions (which cause gravitational “ripples” in space making them ripe for detection); all of them have involved black holes.

But the problem with black holes is that, well, they’re black—and don’t really leave much to observe, Brown explains. The collision that scientists observed Sunday morning, however, “created a pretty spectacular display,” giving scientists insight into the formation of those heavy elements (gold and platinum included) and plenty of fodder to keep working towards the ultimate goal: Figuring out how we all got here.