Spacepod

Dr. Joe Masiero returns to the podcast to talk about asteroid families, which are groups of asteroids that astronomers think are fragments from ancient collisions. He describes how he identifies these families, and how this work can help us understand how the solar system used to be millions of years ago.

Dr Debbie Weiser explains the importance of building an early warning system in the US before a major earthquake hits. Even a few seconds warning is enough to stop elevators, pause surgery, and give peace of mind to everyday folks experiencing aftershocks. To support this program, contact the California Governor's office or your congressional representatives.

Dr. Debbie Weiser talks about human-made earthquakes on my favorite planet, Earth. She explains how seismologists try to distinguish between natural earthquakes and those caused by human activity, and why the earliest seismometers in California were installed by astronomers.

Dr. Driss Takir stops by the show. He explains how he looks for water that's molecularly bound up in the rocks on asteroids. He also tells us about the Hayabusa-2 mission, which will put rovers on the the surface of asteroid Ryugu.

Dr Jennifer Scully talks about the geology of Ceres and Vesta, two large asteroids in the main belt that have been visited by NASA's DAWN mission. She's talks about the experience of getting to know each and every crater, and why the first images from Ceres surprised some people.

Dr. Shantanu Naidu tells us about planetary radar. Using large telescopes in California and Puerto Rico, he bounces radio waves off of asteroids and "listens" for the return signal. With this technique, he's discovered moons on several asteroids.

Dr. Sona Hosseini talks about spectroscopy, a technique that allows scientists to determine what celestial bodies are made of. She's developing new spectrometer that will allow her to look at an entire planet, or comet, all at once.

Dr. Dave Reitze, the Executive Director of LIGO, talks about how each source of noise at LIGO must be meticulously accounted for— from wolves howling, to tidal flexing of the Earth's surface, to the motion of the atoms in the observatory's mirrors.

Dr. Dave Reitze, the Executive Director of the Laser Interferometer Gravitational-wave Observatory (LIGO) talks about the extraordinary detection of gravitational waves earlier this year, and the incredible engineering that made it possible.

Dr. Varoujan Gorjian thoroughly debunks a misconception he hates— the idea that black holes suck. Find out what would happen to the Earth if our Sun was suddenly replaced with a black hole of the same mass, and why is is so challenging to send a probe to Mercury.