Why does a space shuttle get hotter on reentry than on liftoff? Find out on this Moment of Science.
If you find yourself away from a city, spend an hour looking up on any clear, moonless night. You’re bound to see a few brilliant “shooting stars.” These actually have nothing to do with stars: They’re meteors, and if your viewing conditions are good, you can see about seven per hour on any given night.
Microwaves are low energy electromagnetic waves that have so little energy they can’t trigger chemical reactions in the molecules they encounter.