The oldest known intact Earth rock was collected on the moon in the 1970s. Learn how researchers think it got there it in this classic episode of BrainStuff.

BrainStuff Classics: How Did Fish & Chips Become England's National Dish?
07:17

Do Lemmings Really Jump Off Cliffs?
13:23

What Would Happen If You Drank Saltwater?
12:12