We need a better way to map Earth's magnetic field. Finding it could win 1 of these teams $2 million

Close call! 2 huge pieces of space debris had a near-miss in Earth orbit

This weekend NASA will attempt a "highly choreographed" operation to deliver an ancient "grandfather rock," as the team calls it, to Earth. This piece of an asteroid could provide clues about how our solar system evolved, and is the largest sample ever collected from beyond the orbit of the Moon.

Telescope spots NASA's OSIRIS-REx probe as it brings asteroid samples to Earth (photo)