Aliens at the Bottom of the Mariana Trench

What If: Science, Theory, and Possibilities · Oct 16, 2025 · 9m

The captain sounds the alarm. The waters around the ship rumble as strange lights from below move closer. Something is emerging from the Mariana Trench, and it doesn't belong on Earth. If aliens lived in the ocean's deepest place, how would they look and communicate? What might happen if we contact them?

Transcript and sources: What If Show

Timeline:

00:00 - Aliens in Mariana Trench?

00:39 - What lies deep within the ocean?

02:11 - Translucent snailfish and sea cucumbers

02:58 - What would aliens eat at the bottom of the ocean?

04:38 - How would we notice the aliens?

05:35 - Overwhelming…