Cosmic Megafauna - Could Giant Alien Life Forms Exist?

Space is big—but could life out there be even bigger? Join us as we ask just how enormous alien life can get—and what it might look like.

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Credits:
Cosmic Megafauna - Could Giant Alien Life Forms Exist?
Episode 727; June 22, 2025
Written, Produced & Narrated by: Isaac Arthur
Select imagery/video supplied by Getty Images
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
Stellardrone, "Red Giant", "Billions and Billions"

Chapters
0:00 Intro
3:35 The Limits of Size in Biology
7:40 Cosmic Megafauna in Different Environments
8:28 Spaceborne Megafauna: Giant Creatures in the Void
10:18 Could Space Creatures Form Complex Ecosystems?
12:29 Giant Oceanic Creatures: Titans Beneath the Ice
18:23 Fishbowl Starships
19:45 Giants Amid the Clouds: Life Inside Gas Giants
24:53 Terrestrial Kaiju & Sandworms: Monsters on Land
31:01 Megaflora: When the Giants Are Green
34:26 True Cosmic Megafauna: When Worlds and Stars Are Alive
38:14 Final Reflections: Life Without Limits