Dr. Michele Bannister talks about interstellar objects, including the recent discovery of 2I Borisov. Astronomers are observing this object with every available telescope to answer key questions, such as: what is Borisov made of? Is it like comets from our own solar system, or is it "really weird and different"? Dr. Bannister fills us in on the latest results. This episode was recorded on November 13th, 2019.

Dr. Jessie Dotson talks about her asteroid risk assessment research. She describes how she and her team create comprehensive models of asteroid impacts. Their research shows that the consequences of an impact depends on asteroid size and where it hits on Earth.

Dr. Ross Beyer talks about Pluto's companion, Charon. He describes how he derived a theory explaining how Charon's "wonky" plains formed. He compares being a planetary geologist with a crime scene investigator, and tells us the story about how Charon got its name.

Prof. Christine Hartzell tells us about the bizarre ways dust and rock behave on asteroids. She explains, "asteroids are complicated because our intuition fails." Tools like shovels become useless, forcing spacecraft designers to innovate.

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.