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 provide evidence that ancient Mars was habitable and 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. (Recorded live 5 June 2025.)

Why are Titan’s river deltas missing? Planetary astronomer Franck Marchis taps in for Beth Johnson to chat with Brown University’s Sam Birch and explore a strange and unexpected mystery on Saturn’s largest moon. Using data from NASA’s Cassini mission and advanced computer modeling, Birch’s team reveals that Titan's shorelines defy Earth-like expectations. Despite Titan's known rivers and seas of liquid methane, the team found a surprising absence of deltas—landforms typically formed when rivers deposit sediment at their mouths. This finding challenges existing geological expectations, as deltas are common on Earth where rivers meet larger bodies of water, and suggests that Titan's geological and climatic processes differ significantly. This discovery opens new avenues for research into Titan's sediment transport mechanisms and its potential to preserve signs of past environmental conditions or even life. (Recorded live 29 May 2025.)

What if the origin of life isn’t a one-in-a-billion cosmic fluke, but something that happens whenever the conditions are just right? Join communications specialist Beth Johnson as we explore groundbreaking research from the University of Wisconsin–Madison, where scientists have identified over 270 self-replicating chemical reactions that may have sparked life, not just on Earth, but potentially anywhere in the universe. Led by astrobiologist Dr. Betül Kaçar, this study reframes our understanding of how life can emerge from simple chemistry. Discover how these "chemical recipes" might reveal a universal pattern for life, help us search distant planets more effectively, and bring us one step closer to answering one of humanity’s biggest questions: Are we alone? (Recorded live 15 May 2025.)