Beyond the basics we learned at school, what do we really understand about what we see in the night sky? The hosts of BBC's The Sky at Night, astronomers Chris North and Paul Abel take an informed look at our cosmic neighbors—the Sun, the planets, and their moons—as well as the occasional visitors to our planet (asteroids, meteors and comets) and the distant stars. In their chatty style, they also ponder what might lie beyond our Solar System, including the mysterious "Earth Mark II."