Pupil outcome: I can locate and talk about the Arctic Circle using maps and globes, and describe seasonal changes. Key learning points: - The Arctic Circle is an imagined circle around the North Pole that surrounds the area known as the...

This visualization shows gamma rays detected during 3C 279's big flare by the LAT instrument on NASA's Fermi satellite. The flare is an abrupt shower of "rain" that trails off toward the end of the movie. Gamma rays are...

Try as you might, you can't walk in a straight line without a visible guide point, like the Sun or a star. You might think you're walking straight, but as NPR's Robert Krulwich reports, a map of your route would reveal you are doomed to...