This month, we read the history of Martian science in a collection of globes, and find out why it's important to understand ancient and aboriginal astronomy. We find out why some Gamma Ray Bursts (GRBs) are shrouded in darkness, discuss the recent controversy around arsenic-using bacteria and get the high-speed low-down on the Hubble Space Telescope. Plus, we tackle your questions on gravity, relativity and the edge of the universe. Like this podcast? Please help us by supporting the Naked Scientists