When you're a kid, there are two great mysteries that beguile you about the world: what's in outer space and what the hell happened to the dinosaurs?
Well, why the existence of alien life forms remain TBC, a group of researchers from Germany claim to have settled the debate over T-Rex and co for good.
Yup – it's the old 'obliterated by an asteroid' theory, only with more detail than ever before.
A team inspected the famous Chicxulub crater in Yucatan, Mexico and unearthed 260 rocks which they sent back to the University of Bremen in Germany.
There, a bunch of clever adults who never shook off that childhood wonder reconstructed the most detailed theory yet on what precisely happened.
They say the nine mile wide piece of space litter smashed into earth while travelling at 40,000 mph, destroying everything it hit and causing fragment in a 600-miles radiation fireball that burned at approximately 10,000 degree Celsius, which even the really hard dinosaurs like the T-Rex and that fast one from Jurrasic Park would have been pretty hopeless against.
Not only that, but the blast caused fragments of the Earth's crust to explode into the air at heights as large as mountains where it polluted the atmosphere, blocked out most of the world's sunlight and, just for good measure, caused the biggest tsunami in history.
And if that doesn't sound unlucky enough for our absent friends, the researchers also crucially concluded that it was the location of the impact that was the most important – had it landed elsewhere the relatively small asteroid wouldn't have set off this biblical sequence of awful events and dinosaurs may still rule the world.
Professor Alice Roberts said: "As the clouds started to clear, plants came back to life and a tiny group of animals came out of hiding to inherit the Earth. With the dinosaurs gone, suddenly the landscape was empty of competitors and ripe with possibilities.
"Just half a million years after the extinction of the dinosaurs and landscapes around the globe had filled with mammals of all shapes and sizes."
You know the rest: monkeys, men, civilization, war, peace, Trump.
Now what about those aliens?
The team's findings will be feature in The Day the Dinosaurs Died on BBC2 on Monday at 9pm.