A secret Soviet Union experiment and when Britain was buried under ice!

Did you know that 25,000 years ago Britain was buried under miles of ice? We know this by looking at the landscape that the ice carved out and the soils left behind - like mud that formed at the bottom of lakes, that were created when the glaciers melted. Dan chats to researcher Matt Carney to find out more about the last Ice Age.

Plus, we learn about what happened to a secret Soviet Union project to drill as deep as possible into the Earth's crust, our science expert Tom explains how salt got into the oceans and we shrink down to microbe level to meet Bene and Mal!