SETI Live

Earth 2.0? Maybe Not. Intelligent Life Might Be Far Rarer Than We Think


Listen Later

Get ready for a fascinating deep dive into one of the biggest questions in astrobiology: How common are biological extraterrestrial intelligences in the Milky Way? Host Simon Steel, Deputy Director of the Carl Sagan Center for Research, is joined by Manuel Scherf and Helmut Lammer (Space Research Institute, Austrian Academy of Sciences) to explore new research that challenges long-held assumptions about "Earth-like" planets and what it really takes for a world to support complex life. Recent work from Scherf, Lammer, and colleagues revisits the idea of Eta-Earth — the number of truly Earth-like habitats in the Galaxy. Their models extend far beyond the basic "habitable zone" and incorporate a suite of filters, including stable atmospheres, oxygen-rich conditions, plate tectonics, subaerial land, and long-term planetary evolution. These filters significantly reduce the number of planets that could potentially host complex or technological life. The study finds that even under generous assumptions, the Milky Way may host at most 60,000 to 250,000 Earth-like habitats — and the number that actually evolve intelligent life could be far smaller. The result? A serious rethink of how rare (or precious) intelligent life might be. Join us as we explore what this means for SETI strategies, exoplanet surveys, and our own cosmic significance. It's a conversation that blends astrophysics, planetary science, and a bit of existential wonder — perfect for anyone curious about where life fits into the grand structure of the cosmos. Paper: https://www.liebertpub.com/doi/10.1089/ast.2023.0076 Conference Abstract: https://meetingorganizer.copernicus.org/EPSC-DPS2025/EPSC-DPS2025-1512.html (Recorded live 8 December 2025.)

...more
View all episodesView all episodes
Download on the App Store

SETI LiveBy SETI Institute

  • 4.5
  • 4.5
  • 4.5
  • 4.5
  • 4.5

4.5

6 ratings


More shows like SETI Live

View all
StarTalk Radio by Neil deGrasse Tyson

StarTalk Radio

14,329 Listeners

Big Picture Science by Big Picture Science

Big Picture Science

941 Listeners

The 365 Days of Astronomy by 365DaysOfAstronomy.org

The 365 Days of Astronomy

351 Listeners

Planetary Radio: Space Exploration, Astronomy and Science by The Planetary Society

Planetary Radio: Space Exploration, Astronomy and Science

1,351 Listeners

SpaceTime with Stuart Gary by Stuart Gary

SpaceTime with Stuart Gary

326 Listeners

Astronomy Cast by Fraser Cain and Dr. Pamela Gay

Astronomy Cast

2,868 Listeners

Universe Today Podcast by Fraser Cain

Universe Today Podcast

561 Listeners

Space Nuts: Astronomy Insights & Cosmic Discoveries by Professor Fred Watson and Andrew Dunkley

Space Nuts: Astronomy Insights & Cosmic Discoveries

235 Listeners

Science Friday by Science Friday and WNYC Studios

Science Friday

6,426 Listeners

Daniel and Kelly’s Extraordinary Universe by iHeartPodcasts

Daniel and Kelly’s Extraordinary Universe

2,353 Listeners

The Supermassive Podcast by The Royal Astronomical Society

The Supermassive Podcast

332 Listeners

The world, the universe and us by New Scientist

The world, the universe and us

111 Listeners

Why This Universe? by Dan Hooper, Shalma Wegsman

Why This Universe?

390 Listeners

This Week in Space (Audio) by TWiT

This Week in Space (Audio)

156 Listeners

The LIUniverse with Dr. Charles Liu by theliuniverse

The LIUniverse with Dr. Charles Liu

68 Listeners