264 | Sabine Stanley on What's Inside Planets (opens in new tab)

The radius of the Earth is over 6,000 kilometers, but the deepest we've ever dug below the surface is only about 12 km. Yet we have a quite reliable idea of the structure of the Earth's interior -- inner core, outer core, mantle, crust -- not to mention pretty good pictures of what's going on inside some other planets. How do we know those things, and what new things are we learning in the exoplanet era? I talk with astrophysicist and planetary scientist Sabine Stanley about how we use gravit...