We Worked Out What It Would Take to Wipe Out All Life on a Planet--and It's Good News for Alien Hunters

The first exoplanet was spotted in 1988. Since then more than 3,000 planets have been found outside our solar system, and it's thought that around 20% of Sun-like stars have an Earth-like planet in their habitable zones. We don't yet know if any of these host life--and we don't know how life begins. But even […]