A walking tour of the solar system

Part 1: Mercury to Mars

This week on the Audio Guide to the Galaxy, we're going for a walk. No, really - we're walking through the inner planets of our solar system at 175 000km/s. So put your walking shoes on, and let's head into orbit.

You can listen to this episode any time. Yep, even day time.

Tune in next week for part two, which will take us beyond the asteroid belt to the outer Solar System.