Listen to our latest episode!

Subscribe on:

SETI Live is a weekly production of the SETI Institute and is recorded live on stream with viewers on YouTube, Facebook, LinkedIn, X (formerly known as Twitter), and Twitch. Guests include astronomers, planetary scientists, cosmologists, and more, working on current scientific research.

Founded in 1984, the SETI Institute is a non-profit, multi-disciplinary research and education organization whose mission is to lead humanity’s quest to understand the origins and prevalence of life and intelligence in the Universe and to share that knowledge with the world.

Watch The Latest Episode

Mars’ Ancient Carbon Cycle

How Rocks on Mars Tell the Story of a Vanishing Climate

Join planetary scientist Beth Johnson as we explore a groundbreaking discovery from NASA's Curiosity rover on Mars. Scientists have identified siderite—a rare iron carbonate mineral—within ancient Martian rocks, offering new insights into Mars' once-thicker atmosphere and its now-lost carbon cycle. This discovery reshapes our understanding of the Red Planet's climate history and helps us draw powerful parallels to Earth's carbon processes.

Dr. Ben Tutolo, associate professor at the University of Calgary and participating scientist on NASA's Curiosity rover team, explains that as Mars' atmosphere thinned over time, carbon dioxide was sequestered into rock formations, leading to a dramatic climate shift from a warm, wet environment to the cold, arid planet we see today. These findings not only provide evidence that ancient Mars was habitable but also offer insights into the fragility of planetary climates. Dr. Tutolo emphasizes the parallels between Mars' atmospheric changes and current efforts on Earth to mitigate climate change by converting anthropogenic CO₂ into stable carbonates. Understanding the mechanisms of carbon sequestration on Mars could inform strategies to address climate challenges on our own planet.

Learn More Read Press Release Read Paper

Meet Our Hosts

Beth Johnson is a communications specialist and social media manager at the SETI Institute with a degree in physics and master's work in planetary science. She specializes in meteor showers, icy moons, and anything with volcanoes.

Franck Marchis is a senior planetary astronomer at the SETI Institute and Chief Scientific Officer and Founder at Unistellar. He has dedicated his work to the study of our solar system, specifically the search for asteroids with moons, using mainly ground-based telescopes equipped with adaptive optics.

Simon Steel is Deputy Director of the Carl Sagan Center for Research at the SETI Institute. As an observational astrophysicist, he specialized in optical spectrophotometry, with an interest in the star formation histories of galaxies.

Bettina Forget is an art-science researcher, educator, and visual artist who joined the SETI Artist-in-Residence program in 2016 as a Researcher in Residence and became its Director in 2020. In this capacity, she facilitates collaboration between artists and the SETI Institute’s scientists, promotes art-science research, and weaves a network of institutional partners active in art, science, and technology.

Watch SETI Live

SETI LIVE: LaserSETI Update
26 June 2025
2:30 PM - 3:00 PM

SETI Live: Could Aliens See Us?
12 June 2025
2:30 PM - 3:00 PM

Mars’ Ancient Carbon Cycle
05 June 2025
2:30 PM - 3:00 PM

Titan’s Missing Deltas?
29 May 2025
2:30 PM - 3:00 PM

A Cookbook of Life
15 May 2025
12:00 PM - 12:30 PM

Watch More