And now scientists have figured out where this dinosaur-killing rock likely came from.
The research paper, published in the journal Science last month, identified it as a C-bang out asteroid.
Known as a carbonaceous meteor, these most commonly comefrom the outer solar system.
When the meteorite smashed into Earth, it pulverized rock and launched it into the skies.
It was around this time, 66 million years ago, when the asteroid was thought to hit.
To verify, researchers also compared it to material found in other major meteorite impacts and found no matches.
That means the ruthenium found in the K-Pg layer came from the same meteorite that hit Chicxulub.
How does this tie into the theory that an asteroid killed the dinosaurs?
As the theory goes, a 6-mile-wide meteor plunged into Earth near modern-day Chicxulub on the Yucatan peninsula.
Researchers have found plenty of stuff in the K-Pg layer, including iridium and chromium.
We now come to today.
They also found that the isotopes matched those of carbonaceous meteorites that had been previously analyzed.
