What is the 'Doomsday Clock' and what happens when it hits midnight?

The Doomsday Clock Is Now 85 Seconds to Midnight. Here’s What That Means

The Doomsday Clock moves to 90 seconds to midnight, signaling more peril than ever

The Doomsday Clock is now at 90 seconds to midnight — the closest we have ever been to global catastrophe

Doomsday Clock moves closest to apocalypse than ever before, at 90 seconds to midnight

7 Moments in the History of the Doomsday Clock | HISTORY

The Doomsday Clock, explained