The Cretaceous-Paleogene (K-Pg) extinction event, a.k.a. The Fifth Extinction, wiped out about three-quarters of the plant and animal species on Earth 66 million years ago. Can we expect The Sixth Extinction to wipe humans out? If so, when?
Are we alone in the universe or is there intelligent life on other planets? And could aliens travel through space and reach Earth? Phil Plait investigates.
The death of a star can cause catastrophic planetary damage. But what happens when a dying star becomes a Supernova and is Earth at risk? Phil Plait investigates.
