Podcast Summary: ReThinking with Adam Grant

Episode: Searching for Life on Other Planets with Astrophysicist Sara Seager

Date: February 17, 2026
Host: Adam Grant
Guest: Sara Seager, Astrophysicist and Planetary Scientist at MIT

Episode Overview

This episode delves into the search for life beyond Earth, as organizational psychologist and host Adam Grant engages in a wide-ranging, thought-provoking conversation with MIT astrophysicist Sara Seager. Together, they explore the science of exoplanet discovery, ponder the probability of extraterrestrial life, discuss the philosophical and practical implications of finding life elsewhere, and reflect on Seager’s distinctly unusual origin story. The episode also touches on scientific creativity, the value of “pure” research, and what motivates great thinkers to push the boundaries of the unknown.

Key Discussion Points & Insights

1. Sara Seager's Origin Story & Perspective on Science

• Early Fascination:
  • As a child, Seager attended a “star party” with her father and remembers being awestruck by seeing the Moon through a telescope for the first time.
    • “The moon is literally a whole other world and I just thought, wow, what is out there? It’s so huge and vast and magnificent…” (01:01, Sara Seager)
• Formative Family Dynamics:
  • Grew up with an authoritarian stepfather, fostering a distrust of authority, and a whimsical, open-minded father, encouraging creative thinking:
    • “So what I got out of my childhood was... because of my stepfather, like, a distrust of authority and because of my dad openness to crazy ideas that I could think through on my own. And, wow, what a winning combination for science...” (02:49, Sara Seager)

2. The Science of Exoplanet Discovery

• Definitions & History
  • Exoplanets are planets that orbit stars other than the Sun.
  • The field is young; when Seager entered grad school in the 1990s, exoplanets were just being discovered.
    • “...everyone had thought that exoplanets would be like our solar system... And that's not what people found.... evidence just became incontrovertible that exoplanets are real and they're incredibly different from our solar system.” (05:02, Sara Seager)
• Detection Techniques
  • Most exoplanets are found by observing tiny dips in starlight as a planet passes in front of its star (“transiting”).
    • “...we don't spatially resolve those stars. They're just points of light. Yet we can measure the drop in brightness precisely enough to find evidence of planets orbiting their star.” (05:54, Sara Seager)
• AI & Planet Hunting
  • AI is currently assisting with data analysis and efficiency, but hasn’t yet revolutionized the search methods.
    • “For exoplanets, it's really done more of that first category, just done things that we can do better, faster... It hasn't really found like a new path, a new way to do things.” (07:00, Sara Seager)

3. The Scale of the Universe & Likelihood of Extraterrestrial Life

• Exoplanet Abundance
  • Estimates of “trillions” of exoplanets in our galaxy alone.
    • “Trillions. Trillions. In our galaxy alone. We have just scratched the surface.” (07:40, Sara Seager)
• Intelligent Life?
  • Surmising that intelligent life should exist somewhere, though biologists remain skeptical due to our ignorance of the origin of life mechanisms.
    • “Biologists don’t like this... because we don’t understand how life originated on Earth, and so we cannot assume that it originates elsewhere...” (08:42, Sara Seager)
  • Both agree: If life arose independently more than once, “the chance then is just so believable that it’s happening elsewhere.” (09:31, Sara Seager)
• Probability of Discovery
  • Seager’s personal estimate on finding intelligent life in our lifetimes is “pretty low... I might even put it at zero for now.” (10:35, Sara Seager)
    • The search focuses on nearby stars, where our capabilities allow.

4. What Would Discovery Mean for Humanity?

• Cosmic Perspective

  • Would shift our understanding of our place in the cosmos, continuing humanity’s historical “de-centering” from the universe.
    • “...it kind of carries us forward in this cosmic story of what is our place. How do we fit in?” (11:31, Sara Seager)
  • Everyday life likely would not change immediately.

• Timeline for Even Simple Life Detection

  • Non-intelligent (microbial) life detection is much more plausible soon.
    • “...we hope to have evidence for [simple life]... in our lifetime. Starting with our solar system, the subsurface of Mars... the clouds of Venus... the subsurface of one of Jupiter’s or Saturn’s icy moons...” (12:21, Sara Seager)
  • Exoplanet atmospheric analysis looks for “gases that don’t belong” as biosignatures.
    • “...we’re looking there for signs of life... gases that don't belong. Like here on Earth, we have oxygen... But without life... we'd have no oxygen...” (12:21, Sara Seager)

5. The Fermi Paradox and the “Ants” Analogy

• Fermi Paradox Explained
  • The tension between the high likelihood of life and complete lack of evidence.
• Possible Solutions
  • Technological or distance barriers could explain why we haven’t found (or been found by) extraterrestrials.
    • Seager’s favorite: "It’s like the ants. ...Would you talk to those ants? ...I actually like to think we're the ants. We are the ants to the super intelligent beings out there. And, like, why would they come here and talk to us?" (15:07, Sara Seager)
• Are We Being Observed?
  • “Maybe they're studying us. Just like if we study the ants, do they know we're studying them?” (16:12, Sara Seager)

6. Should We Be Making Contact?

• Debate in Astronomy
  • Ongoing vigorous debates among astronomers about sending Earth signals or messages.
    • “...that debate is actually an active one.” (17:15, Sara Seager)
• Seager’s View
  • "I don't think it matters... others could find us if they're there and if they have the technology..." (17:32, Sara Seager)
• First Contact
  • If the technology gap is narrow, discovery may take millennia either way.
  • Seager would make first contact if possible, but reiterates, “if they have the ability to come to us, then they already know we’re here.” (18:40, Sara Seager)

7. Why Search for Life (and Practice Pure Science) When We Have Earthbound Problems?

• STEM Inspiration
  • Astronomy excites & inspires, drawing future scientists into STEM, producing needed technologists and innovators.
    • “We communicate to the public the wonders of science... One of the main things is just to attract more people to Science, we need astronomy to show people how great it is.” (23:17, Sara Seager)
• Unexpected Payoffs
  • Pure research often leads to unpredictable, transformative innovations (e.g., GPS, lasers, medical imaging).
    • “You have a ton of stuff happening... That's why in astronomy we take credit for some medical imaging, because we had to translate our data to images.” (23:17, Sara Seager)
  • Adam Grant connects this to creative theory: “Idea generation requires a tremendous amount of variety. There's going to be a lot of noise and the challenge is to find the signal and then hone in on it.” (25:24, Adam Grant)

Memorable Quotes & Moments

• On cosmic insignificance:
  • “So if that doesn’t make you feel insignificant, like, what does?” (08:28, Sara Seager)
• On humility in the face of the cosmos:
  • “We shouldn’t be so arrogant as to assume that we are alone in the universe.” (32:46, Adam Grant)
  • “It’s just self centered, really... I like that view because... confronting like our own tragedies against the vastness of the universe, it somehow brings comfort.” (33:00, Sara Seager)
• On advice for aspiring scientists:
  • Worst advice: “Don’t go into astrophysics. You’ll never make it.” (27:54, Sarah Seager)
  • Best advice she gives: “Hone your inner voice... try to develop that inner voice.” (28:06, Sarah Seager)
• On unexpected life:
  • “Yes. Right now it’s that there could be life... in the clouds of Venus... made of concentrated sulfuric acid that kills all of our life instantly.” (28:45, Sara Seager)
• On the motivation to keep searching:
  • “We just want to know what is out there, who might be out there.” (21:02, Sara Seager)

Notable Segment Timestamps

• Sara’s origin story & childhood influences – 02:49
• What is an exoplanet & how are they detected? – 04:41 | 05:54
• The number and diversity of exoplanets – 07:40
• Probabilities and challenges in finding intelligent life – 10:35
• Cosmic implications of discovering life – 11:31
• Signs of microbial life & possible locations – 12:21
• Fermi Paradox and “ants” analogy – 15:07
• Risks & debates over making contact – 17:15
• Value of astronomy & public understanding – 23:14
• The case for pure science & unexpected innovation – 25:24
• Quick-fire advice and favorite space films – 27:44–29:58
• Concluding on humility, perspective, and coping – 33:00

Episode Tone

The conversation is lively and deeply curious, blending scientific rigor with imagination, humility, and a sense of wonder. Both Adam Grant and Sara Seager demonstrate openness to bold ideas and a drive to push intellectual boundaries, balancing skepticism with awe at the scale and mystery of the universe.

This summary captures the essence and flow of the episode, spotlighting scientific explanations, debate, and moments of personal reflection. Whether you're a space enthusiast, an aspiring scientist, or simply curious, it offers a thoughtful primer on the thrilling search for life across the cosmos.