The Doomsday Clock now stands at 89 seconds to midnight, the closest to catastrophe in its nearly eight-decade history. Here's a look at how — and why — it's moved.

What is the Doomsday Clock? It's 2025 and scientists have reset the clock closer to midnight and global catastrophe. Here's what it all means.

Therefore, we are moving the clock forward," said Daniel Holz, chair of the Science and Security Board of the Bulletin of the Atomic Scientists, according to CBS News."The war in Ukraine remains a source of nuclear risk,