So I was sitting in Classic Civ today, bored out of my effing MIND, when I came up with this.

WHAT IF:

Aliens visited this planet.... 65 million years ago.

They saw Earth as a habitable planet worthy of colonization. They landed, tried to settle, but couldn't figure out a way to get rid of those pesky dinosaurs. They tried and tried and tried, but big poppa T-rex kept eating them alive. Velociraptorswould overwhelm and chomp on them every time they tried to go out and take geological surveys. They could never fully understand this planet because they just couldn't coexist with the life on it.

So when they finally got fed up with Earth, they went back up to their space ships and used a tractor beam to get the biggest rock in the asteroid belt. They flung it towards Earth as a symbolic middle finger to it inhabitants.

Then they disappeared into the cosmos from whence they came.

It totally could've happened. If you think about it.