Discovering the first true "alien Earth" is a long-held dream of astronomers — and recent exoplanet discoveries have shown that small, rocky worlds like our own are abundant in the galaxy. Let’s look at some of the closest known analogues to our home planet. --- Support this podcast:...

NASA's Curiosity rover is currently roaming Mars' landscape looking for signs of life and learning about the Red Planet's unique environment. Curiosity has four main science goals: Determine whether life ever arose on Mars. Characterize the climate of Mars. Characterize the geology of...