In 2018, a Spanish astronomer proposed that we could detect the network of satellites an alien civilization might put in orbit around their home planet.
About twenty thousand years ago, during the last major ice age, a miles-thick ice sheet covered all of Canada and most of the northeastern United States.
Most of us picture astronauts bouncing gracefully on the moons surface, but what we don't see are the crash landings!
Learn how NASA scientists are taking homeland security into outer space.
What's the biggest magnet ever? Find out on this Moment of Science.