This season's final arc is set in southwest Greenland. Let's start with the most common rocks in the region: what are they and what stories do they tell about the world 3.9 billion years ago?

Along the way, we'll weave a tapestry of rock, boil some rocks, and learn a bit about Dylan's birthstone.

Extra credit: try the Play-Doh experiment from this episode, or make some stone soup.

Earth’s crust is shattered into dozens of moving plates, but many other worlds operate very differently. What are some alternatives to plate tectonics?

Today, we’ll compare tectonics on Earth with tectonics on other planets, through the lens of 3.9 billion-year-old rocks from Greenland. On the way, we’ll visit the westernmost town in the USA, visit one of our cosmic neighbors, and learn about the Occam’s Razor of geology.

Extra Credit: find today’s planet in the night sky, drop a pebble every day this week and see if anything changes, or read “The Long Rain” by Ray Bradbury.