Big Ideas: New Clues to Dinosaurs' Demise and Wolf Puppies Play Fetch

Was it a meteorite or a volcano that made dinosaurs extinct 66 million years ago? Scientists present new evidence. Plus, a new study reveals that some gray wolves can also play fetch. And, here's everything 2020 could bring in spaceflight.

Big Ideas: New Clues to Dinosaurs' Demise and Wolf Puppies Play Fetch

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