One significant threat to life here on Earth is the possibility that a massive asteroid will collide with our planet and destroy life as we know it. To understand the possibilities, large surveys of the sky have found around 95% of potentially hazardous asteroids larger than a kilometer. Smaller asteroids, however, can also cause massive amounts of damage. Estimates range from 40 to 60 percent when it comes to asteroids over 100 meters in diameter, which would be considered city-killers. Even smaller asteroids, such as the 20-meter one that exploded over Chelyabinsk in 2013, can cause destruction and injury. The more asteroids we can find, the better our predictions and future protections will be. In light of this threat, scientists have used the JWST to detect 138 of the smallest asteroids (as small as 10 meters) ever observed in the asteroid belt. These tiny asteroids are important because they can become near-Earth objects (NEOs), posing a risk to Earth through possible impacts, including powerful explosions. By analyzing the size and frequency of asteroids, researchers found a significant change in the population of asteroids around 100 meters in size, likely due to collisions breaking larger asteroids into smaller ones. The observed asteroids originated from known asteroid families and were detected using advanced tracking and infrared imaging techniques. This research enhances our understanding of asteroid behavior and may aid in predicting and mitigating future asteroid threats. Join planetary astronomer Franck Marchis in a conversation with lead authors Artem Y. Burdanov and Julien de Wit as they discuss these smaller asteroids and what they can reveal about potential threats to our planet. (Recorded live 1 May 2025.)

​A recent study proposes a new model for the evolution of intelligent life, which challenges the long-standing "hard steps" theory that the emergence of intelligent life is an exceedingly rare event due to a series of improbable evolutionary milestones. A team led by postdoctoral researcher Dan Mills from the University of Munich suggests that the development of intelligent life is a natural outcome of planetary evolution. They argue that Earth's environment underwent sequential "windows of habitability," periods when conditions became favorable for complex life to emerge. (Past Drake Award winner Jason Wright is a co-author on the study.) The study emphasizes the importance of interdisciplinary collaboration between astrophysics and geobiology to understand the evolution of life. Join planetary astronomer Franck Marchis in an in-depth discussion with Dr. Mills about why intelligent life may be common and how this could affect our search for life beyond Earth. (Recorded live 24 April 2025.)

Join Dr. Franck Marchis, Chief Science Officer and co-founder at Unistellar and director of Citizen Science at SETI Institute, and Dr. Lauren Sgro, Outreach Manager at the SETI Institute, for a conversation on citizen science with the Unistellar network in partnership with the SETI Institute. We will give an update on T CrB, share our new Satellites mode, discuss an exoplanet candidate campaign to confirm a planet, and look ahead to an occultation of asteroid 319 Leona. We will also answer your questions about our program from the Unistellar community page and discuss recent highlights. (Recorded live 17 April 2025.)

A road trip to a gypsum quarry in Algeria led Youcef Sellam on a journey of scientific discovery. From the road trip to an internship in Italy, he and his colleagues later discovered microbial fossils—marking a first for Algerian gypsum. As a Ph.D. student at the University of Bern, Sellam and his team took this research further. They used a special instrument to detect the chemical signatures of these ancient microbes, demonstrating a method that could one day help search for traces of life on Mars. Their findings, published in Frontiers in Astronomy and Space Sciences, highlight how chemical analysis can reveal biological traces in minerals. Join planetary scientist Beth Johnson and Youcef for a discussion of how this research brings us one step closer to understanding how we might detect past life on the Red Planet. (Recorded live 10 April 2025.)

In a recent study, Dr. Janice Bishop of the SETI Institute, along with postdoctoral researcher Adomas Valantinas from Brown University, propose that Mars' characteristic red hue is primarily due to ferrihydrite—a water-rich iron oxide mineral—rather than the previously assumed hematite. Analyses of data collected by Martian orbiters, rovers, and laboratory experiments showed that ferrihydrite closely matches the composition of the dust covering Mars' surface. Ferrihydrite typically forms in environments abundant in cool water, suggesting Mars once had significant liquid water on its surface. The research implies that Mars transitioned from a wet to a dry environment billions of years ago. Confirming these findings would require returning samples from Mars to Earth for comprehensive analysis. Join planetary scientist Beth Johnson for a chat with Dr. Bishop about the evidence for ferrihydrite and what it could have meant for life on Mars. (Recorded live 3 April 2025.)

In The Climate Chronicles, a podcast with 42 episodes across eight seasons, Professor Dagomar Degroot of Georgetown University "takes you on a journey through 50 million years of climate change." He delves into how climate change has shaped civilizations—from the earliest hominid ancestors to the present era of rapid global warming. Through storytelling and historical analysis, he reveals the profound influence of climate on human societies. He explains how lessons from the past can help us navigate the challenges of today and tomorrow. Join communications specialist Beth Johnson for a conversation with Professor Degroot. They will explore the intricate connections between climate, human history, and future challenges. (Recorded live 27 March 2025.)

With over 7,000 exoplanets identified in our galaxy, scientists are shifting their focus to studying these worlds' characteristics in the quest for extraterrestrial life. The backdrop for one team is the discovery of super-Earth HD 20794 d, an exoplanet detected by researchers from the University of Geneva (UNIGE) and NCCR PlanetS. Orbiting in an eccentric path, HD 20794 d moves in and out of its star’s habitable zone, making it a compelling subject for further study. This breakthrough, built on two decades of observations with the world’s most advanced telescopes, has just been published in Astronomy & Astrophysics. Join planetary astronomer Franck Marchis and lead author Nicola Nari for a discussion on the search for exoplanets, what a habitable world could look like, and how HD 20794 d will help us understand our universe. (Recorded live 20 March 2025.)

The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) mission has been a resounding success, from taking a sample of asteroid Bennu to returning that sample to Earth. The first in-depth analysis of the space rocks is complete, and the results have been published in Nature and Nature Astronomy. One of the most intriguing results shows that 14 of the 20 amino acids life on Earth uses to form proteins have been found in the sample. This result supports the hypothesis that objects that formed farther from the Sun provided precursor ingredients for life. Join communications specialist Beth Johnson and senior sample scientist Danny Glavin from NASA's Goddard Space Flight Center for a discussion of these important results and their implications for the development of life. (Recorded live on 13 March 2025.)

NASA’s Polarimeter to Unify the Corona and Heliosphere, or PUNCH mission, is a constellation of four small satellites in low Earth orbit that will make global, 3D observations of the Sun’s corona to better understand how the mass and energy there become the solar wind that fills the solar system. Imaging the Sun’s corona and the solar wind together will help scientists better understand the entire inner heliosphere—the Sun, solar wind, and Earth—as a single connected system. Solar wind and energetic solar events like flares and coronal mass ejections can create space weather effects throughout the solar system. These phenomena can significantly impact human society and technology, sparking and intensifying auroras, interfering with satellites, and triggering power outages. The measurements from PUNCH will provide scientists with new information about how these potentially disruptive events form and evolve. This could lead to more accurate predictions about the arrival of space weather events at Earth and the impact on humanity’s robotic explorers in space. The launch of PUNCH and the SPHEREx mission is scheduled for no earlier than 27 February 2025 from Vandenberg SFB. Simon Steel, Deputy Director of the Carl Sagan Center, and MUSE Outreach Lead Rebecca Robinson will attend the launch and return to the SETI Institute for a chat about the mission, its scientific goals, and its relevance to understanding life on Earth. (Recorded live 6 March 2025. PUNCH launched on 11 March.)

During his time as an Artist in Residence (AIR) at the SETI Institute, visual artist, psychiatrist, and psychoanalyst Martin Wilner invited prominent SETI Institute scientists to participate in his ongoing project, The Case Histories. Interested in exploring how scientists relate to the possibility of encountering an alien life form, Wilner invited researchers such as Jill Tarter, Seth Shostak, and Franck Marchis to send him daily messages and share thoughts of interest. These messages, filtered through the prism of psychoanalytical principles, were then transformed into drawings and visualized as daily elements of a calendar. More recently, Wilner has expanded his conversations into the realm of AI, an “alien” intelligence that is already in our midst. In this conversation, hosted by SETI AIR Director Bettina Forget, discover how Wilner weaves connections between the human mind, machine learning, consciousness, and our ideas about extraterrestrial life. (Recorded live 27 February 2025.)