Not only do we know what killed the dinosaurs, we now know when.
Give or take 11,000 years.
Physicist Paul Renne from the Berkeley Geochronology Center reported that they think an asteroid struck the earth 66,038,000 years ago, according to the San Francisco Chronicle.
That's within 33,000 years of a mass extinction, meaning the "asteroid killed the dinosaurs" theory now has more legs.
Of course, other scientists for 30 years have hotly debated this theory, the newspaper reported. Some say that volcanic eruptions ruined the earth's climate enough to kill off life.
Walter Alvarez and his father Luis, a Nobel winner, first posited the cosmic event theory in 1980.
Using a "high-precision dating technology," scientists have connected dinosaur fossils found en masse to around the time a comet or meteor hit the earth.