Two years ago, a team of scientists used an incredibly advanced telescope to observe two neutron stars in a distant galaxy colliding together in a super explosion. The force of that explosion reached all the way to our galaxy hundreds of millions of light-years away.
But according to new research, we didn’t actually have to look hundreds of millions of light-years away to find colliding neutron stars. That’s because one such collision happened right in our own backyard a long time ago.
In a new study, researchers at Columbia University and the University of Florida found hints of the collision in the same area as our solar system about 4.6 billion years ago. This predates the formation of the Earth by about 100 million years. The researchers estimate that our solar system was about 1000 light-years away from the boom when it happened.
The reason scientists were able to gather this much information about an event that predates our own planet is thanks to the leftover materials from the explosion. When neutron stars collide, they undergo a unique fusion process that creates dozens of elements and isotopes that can’t form any other way. The researchers were able to find several of these elements in meteorites that crashed to Earth.
Many of these elements are radioactive, so they decay into other elements at specific rates. By measuring how many of these elements have already decayed, the scientists can calculate when the neutron star collision happened.
Similarly, by measuring the total amount of every element from the collision, the scientists can figure out how far away the explosion was from us.
These elements include a small number of our heavy metals like gold and platinum, radioactive elements like uranium, and other heavy elements like iodine. Some of that iodine—about an eyelash worth—resides in the bodies of each of us, a little leftover reminder that one of the biggest explosions in the universe once happened right next door.
Originally published on Popular Mechanics