Water and the possibility of life on Mars

Water and the possibility of life on Mars

Author: PNAS June 16, 2025 Duration: 15:07

Water and the possibility of life on Mars

Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us.

In this episode, researchers explain what we know about the potential for water and life on Mars and what we might learn from analysis of returned samples.

In this episode, we cover:
•[00:00] Introduction
•[01:04] Mark Thiemens explains the importance of bringing samples from Mars back to Earth.
•[02:37] Arya Udry explains the current gaps and limitations in the geological record provided by Martian meteorites.
•[03:55] Bruce Jakosky explains what we currently know about the presence and history of water on Mars.
•[05:26] Monica Grady explains how analyzing volatile species in Martian samples could provide insight into the planet's past climate.
•[06:58] Rachel Slank describes the potential presence of liquid brines on Mars.
•[08:27] Vashan Wright used recordings from a seismometer onboard NASA's InSight lander to estimate the volumes of liquid water that might be contained in the Martian mid-crust.
•[10:14] Mark Sephton explains what biomarkers are and what kinds we might expect to find in Martian samples.
•[11:34] Caroline Freissinet describes the discovery of long-chain organic molecules on Mars and the difficulties of conclusively identifying organic molecules as biomarkers.
•[13:32] Thiemens explains the potentially far-reaching value of continuing to support the Mars Sample Return mission.
•[14:37] Final thoughts and conclusion.

About Our Guest:
Mark Thiemens 
Distinguished Professor of Chemistry and Biochemistry
University of California at San Diego

Arya Udry
Associate Professor – Graduate coordinator
University of Nevada, Las Vegas

Bruce Jakosky
Professor Emeritus
University of Colorado Boulder

Monica Grady
Professor Emirita 
Open University

Rachel Slank
Postdoctoral Fellow
Lunar and Planetary Institute

Vashan Wright
Assistant Professor
University of California, San Diego

Mark Sephton
Professor
Imperial College London

Caroline Freissinet
Researcher
Laboratory for Atmospheres, Observations, and Space
French National Centre for Scientific Research

View related content here: https://www.pnas.org/doi/10.1073/pnas.2421996121
https://www.pnas.org/doi/10.1073/pnas.2415280121
https://www.pnas.org/doi/full/10.1073/pnas.2404254121
https://www.pnas.org/doi/full/10.1073/pnas.2321080121
https://www.pnas.org/doi/full/10.1073/pnas.2404260121
https://www.pnas.org/doi/full/10.1073/pnas.2321067121
https://www.pnas.org/doi/full/10.1073/pnas.2409983121
https://www.pnas.org/doi/full/10.1073/pnas.2404256121
https://www.pnas.org/doi/full/10.1073/pnas.2420580122

Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs!

Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast 

Follow PNAS:
Twitter/X
Facebook
LinkedIn
YouTube
Sign up for the PNAS Highlights newsletter


Tune into PNAS Science Sessions for a direct line to the people shaping modern science. Produced by PNAS, this podcast offers more than just summaries of published research; it’s where you hear the candid, often personal stories behind the headlines. Each episode features concise conversations with the researchers themselves-from emerging voices to established Academy members-alongside the policymakers whose decisions are informed by this work. You’ll get a genuine sense of the questions that drive these experts, the unexpected hurdles they face in their labs and field studies, and why their findings matter right now. The scope is deliberately wide, reflecting the interdisciplinary nature of science itself, covering discoveries that range from microscopic processes to planetary-scale phenomena. This isn't about dry lectures, but about capturing the human endeavor of investigation. For anyone curious about how science actually unfolds and wants to understand the context of breakthroughs as they happen, this podcast serves as an essential, engaging resource. It connects the dots between a published paper in a prestigious journal and the real-world implications that ripple out from it.
Author: Language: English Episodes: 50

PNAS Science Sessions
Podcast Episodes
Swamp lights and bat sight [not-audio_url] [/not-audio_url]

Duration: 10:26
Swamp lights and bat sight Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the beh…
Enzyme linked with brain evolution [not-audio_url] [/not-audio_url]

Duration: 10:42
Implications of a mutation in modern humans Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific communi…
Where primates evolved [not-audio_url] [/not-audio_url]

Duration: 10:48
Where primates evolved Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-…
How climate change alters lake oxygen levels [not-audio_url] [/not-audio_url]

Duration: 10:06
Climate change and lake oxygenation Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Lear…
Unpacking the unreturnable squash nick shot [not-audio_url] [/not-audio_url]

Duration: 10:07
The physics of the squash nick shot Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Lear…
North America's oldest pterosaur fossil [not-audio_url] [/not-audio_url]

Duration: 10:40
A pterosaur and its ecosystem at the end of the Triassic Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scien…
Exploring the origins of a glacial relict seal [not-audio_url] [/not-audio_url]

Duration: 10:39
The postglacial history of the Saimaa ringed seal Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific c…
Conservation of the Eastern Black Rhinoceros [not-audio_url] [/not-audio_url]

Duration: 10:48
Managing eastern black rhinoceros populations with genetic studies Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to tod…
Rescuing the northern white rhino [not-audio_url] [/not-audio_url]

Duration: 10:50
A reference genome aids efforts to rescue the northern white rhinoceros Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant t…
Machine learning and climate risk adaptation [not-audio_url] [/not-audio_url]

Duration: 10:41
Using reinforcement learning to plan for an uncertain climate future Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to t…