OSIRIS-REx and the Hayabusa spacecraft have sample asteroids to understand what they're made of. NASA sent the DART mission to change the orbit of a tiny asteroid orbiting another asteroid. ESA sent Hera as a follow-up mission to see what the impactor did. All of these missions have been done in the name of planetary defense -- protecting Earth from the worst of the rocks in space. While none of the asteroids so far discovered are a threat to our planet in the next century, there are still more out there that are small enough to do major damage to a city or even country. So what do we do if we find a near-Earth asteroid that's a real threat? Launch a team a la "Armageddon"? Ignore the problem? Try to flee off-planet or below ground? As DART showed, the best answer seems to be "move it out of the way". In his new book "How to Kill an Asteroid", Dr. Robin George Andrews tells the story of planetary defense and how we got to this point in saving ourselves. Join communications specialist Beth Johnson in a fun (and slightly scary) conversation with Dr. Andrews about killer asteroids this Halloween on SETI Live. (Recorded 31 October 2024.)

In September 2022, a small spacecraft called DART hit the surface of a tiny asteroid moonlet called Dimorphos. That spacecraft was the first test of a planetary defense system, attempting to change an asteroid's orbit in the hope of being able to do so under a real near-Earth threat. The test succeeded, shortening the moonlet's orbit by 32 minutes. Now, a follow-up mission called Hera is on its way to the system, complete with an orbiter and a lander. The European Space Agency plans to observe the impact site and measure any changes to the shape and any craters left behind. Join communications specialist Beth Johnson as she chats with Hera's principal investigator, Patrick Michel, from the Université Côte d'Azur about the mission, the science, and the technology being tested. (Recorded live 24 October 2024.)

The cosmos is full of huge questions: "What caused the Big Bang? What happens inside black holes? Are there other dimensions?" Scientists have been working to answer these questions, but sometimes, we feel like the answers are unknowable. Astrophysicist Kelsey Johnson contemplates what this paradox means for science, particularly where philosophy and even religion come into play. In her latest book, "Into the Unknown", Johnson takes us to the edge of our understanding. Join communications specialist Beth Johnson as she chats with author Kelsey Johnson about science, philosophy, and our quest for answers that may not be available. (Recorded live 21 October 2024.)

In 1976, NASA's two Viking spacecraft touched down on Mars, becoming the first successful landers on the red planet. On board Viking 1, the craft carried several biological experiments to search for life. While most scientists consider the results of those experiments to be negative for Martian life, one experiment gave a positive result. The resulting controversy has spanned decades, with numerous scientists weighing in. Now, Dirk Schulze-Makuch from the Centre of Astronomy and Astrophysics (ZAA) at Technische Universität Berlin questions how those experiments were performed in light of what we know of extremely dry environments here on Earth. These Mars analogs, such as the Atacama desert in Chile, show that while microbes can survive in harsh conditions, too much water becomes a problem. And those Viking experiments may have involved too much water. Join Dr. Franck Marchis as he discusses Dr. Schulze-Makuch's recent Nature Astronomy article and how we should follow the salts instead of the water. (Recorded 28 October 2024.)

Suppose global warming raised temperatures so drastically that crops failed and caused world hunger. Would you support the idea of gene editing humans’ skin cells so that photosynthesis would become an alternative source of human nutrition? The Non Random Arts Collective, part of the SETI Institute’s Artist in Residence (AIR) program, explores fascinating scenarios connecting climate change, habitability, and gene editing. SETI AIR Director Bettina Forget chats with the collective about their GAIA workshop series, which they led at the SETI Institute this summer, where they invited scientists and artists to engage with the intricacies of climate adaptation, space exploration, and genetic research. The Non Random Arts Collective consists of Linda O’Keeffe, Ashley James Brown, Tony Doyle, and Ines Montalvao. Together, they delve into the intersections between the arts and diverse fields such as astrophysics, genetics, urban planning, ecology, climate change, technological adaptation, AI, and design futures. (Recorded live 17 October 2024.)

Comets are small objects in our solar system made of ice and dust. As they get closer to the Sun in their orbits, the ices turn into gas and give off a glow that can be seen in telescopes. With luck, that glow brightens to the point where a comet can be seen with the unaided eye. Some, like Halley's Comet, return on a regular schedule. Others are more one and done, breaking apart as they near the Sun or getting a gravity assist to leave our solar system. And every year, astronomers hope for the "comet of the century" -- a rare but visible comet that provides a show with a glorious coma and tail. This October, the observing community hopes that not just one but TWO recently discovered comets will put on that show. This week, Beth Johnson is joined by Dr. Ariel Graykowski, the Cometary Activity Lead for the SETI Institute and Unistellar citizen science project, to chat about the search for comets and the hope that either Comet C/2023 A3 Tsuchinshan-ATLAS or C/2024 S1 (ATLAS) will soon be visible to the unaided eye. (Recorded 3 October 2024.)

Exoplanets are planets that orbit stars outside our solar system. We've been finding potential exoplanets more often since the Kepler and TESS spacecraft were launched. But confirming these planets takes time, and telescope time is limited. To speed up the process, amateur astronomers are using their own telescopes. One program, called UNITE (Unistellar Network Investigating TESS Exoplanets), brings together a global group of volunteer and professional astronomers. They use Unistellar telescopes to gather data when exoplanets pass in front of their stars, blocking some of the light. Scientists from the SETI Institute and Unistellar analyze this data. Recently, they confirmed two exoplanets—a hot Jupiter and a warm sub-Saturn. Dr. Lauren Sgro, UNITE’s Exoplanets Lead, talks with communications specialist Beth Johnson about exoplanets, community science, and how science is evolving. (Recorded live 19 September 2024.)

In the quest to find life beyond Earth, icy worlds within our solar system are full of potential. Europa, one of Jupiter's four largest (Galilean) moons, is one possible target because of the vast ocean beneath its icy shell. That ocean, heated by the push and pull of Jupiter, could contain life. The Europa Clipper mission will send a spacecraft to the distant moon, and the spacecraft's instruments will determine if the conditions truly are suitable. This week, NASA announced that Europa Clipper passed another milestone toward the October 10 launch window. Communications specialist Beth Johnson is joined by Project Staff Scientist and Science Communications Lead Cynthia Phillips to discuss the mission and how it could answer the question, "Are we alone?" (Recorded live 12 September 2024.)