Dr. Bill Bottke stops by the show to talk about ancient craters on the Moon and Earth. He tells us about how you can figure out crater ages by looking at the nearby rocks, and how that led him and his colleagues to figure out that the impact rate on Earth changes with time.
Dr. Jeff Rich returns to the show to talk about the night sky. He explains how astronomers used constellations to communicate. He also tells us that anyone can invent their own constellation. In a time when people can create "universes inside a computer," we talk about ways to go outside and experience the cosmos.
Dr. Carolyn Ernst tells us about DRACO, a camera on the DART mission. DRACO will take critical images in the final seconds of the mission. Dr. Ernst talks about how heritage is important in spaceflight and explains how DRACO is designed to endure harsh conditions.
Dr. Mark Boslough describes what happens when an asteroid enters Earth's atmosphere. He tell the story of how he learned of the historic 2013 Chelyabinsk impact. He also shares what it was like to see the effects of the Shoemaker-Levy 9 Jupiter impact.
Professor Cristina Thomas talks about NASA's first planetary defense mission: DART. DART is a spacecraft that will impact a tiny asteroid moon. She explains why ground-based telescope observations are key to the mission's success.
Dr. Matthew Knight tells us about a discovery that excited astronomers all around the world. 'Oumuamua is the first minor planet from outside our solar system that we have found. Dr. Knight describes what it was like to observe this speedy object, and explains how it compares to local asteroids and comets.
Dr. Terik Daly talks about his experiments, where things hit other things at tens of thousands of miles per hour. These experiments create pressures greater than that at the center of the Earth, and temperatures hotter than the surface of the sun. Dr Daly tells us what it is like to design and witness these experiments, and how he uses them to learn about the solar system.
Sarah Kaplan of the Washington Post talks about science reporting. Reporters often tackle topics that are outside their expertise. Sarah explains the methods she uses to get at the truth. She also shares where she would send a billion dollar spacecraft, and tells the story of how a small bird caused a big newsroom debate.
Dr. Nancy Chabot returns to the show to talk about iron meteorites. Iron meteorites, she explains, are cores of small planets that you can hold in your hand. She describes her laboratory experiments which use furnaces, glass tubes, and tiny hammers.
Dr. Michael Marsset and his collaborators use the world's biggest telescopes to image asteroids. They combine those images with other data to get shapes of asteroids. These results are comparable with spacecraft images, but are much less expensive. Dr. Marsset talks about new discoveries they have made using this technique.
Dr Spencer Backus talks about his work at NASA's Jet Propulsion Laboratory. He explains the complexities of trying to design hands for robots. An example of a robot hand is the undersea gripper he worked on, which looks like "an angry starfish." He also talks about the benefits and challenges of in-space assembly of spacecraft.
Dr. Jacob Izraelevitz describes how engineers might design a balloon to explore Venus. This work is in the early stages, what NASA refers to as a "Mission Concept." He also explains the challenges of Venusian exploration.
When taking a sample of the Moon's surface, the Apollo astronauts discovered a sharp transition from powdery soil to harder rock. This transition was entirely unexpected, and remained unexplained for decades. Dr. Ivy Curren talks about an experiment she designed to explain this phenomena. She also tells us about a type of lunar dust formation that scientists call "fairy castle structures."
Dr. Seager explains how she and other astronomers are looking for extraterrestrial life. We discuss the Drake and Seager equations. We also talk about how astronomers might be able to detect life by measuring chemicals in distant planet atmospheres. This episode is related to the March 2019 National Geographic cover story, "We are not alone."
Dr. Alicia Lanz talks about the history of astronomical instrumentation, starting with the first telescope. She describes some bizarre historical telescopes and shares a surprisingly inspirational story about bubbles in glass.
Professor Katelyn Allers talks about how you can discover small cold stars! She is a member of the Backyard Worlds project, which is a collaboration between astronomers and citizen scientists. This project searches for brown dwarfs, which are some of the closest objects to our solar system.
Brent Barbee returns to the show to talk about deflecting asteroids. He explains how an asteroid might react to an impact, and also talks about the proposed DART mission, which would change the orbit of a small asteroid moon.
Dr. Solange Ramirez returns to the show to talk about her new position as Project Manager of the Sloan Digital Sky Survey V. Amount other things, the project will study over six million stars and how black holes change over time. These millions of measurements will be made using a robotic telescope system that is currently being built.
Rob Seaman of the Catalina Sky Survey talks about time, and why you need to know the time to discover asteroids and comets. He explains how he installed a highly accurate clock, and makes the case that "natural time" is better than "cold, heartless atomic time."