Join Professor Brian Cox and Dara O Briain live from Australia, as they complete their three-night mission to bring you the most glorious sights of the southern night sky.From their remote mountain top beside the vast Warrumbungle National Park, Brian and Dara share another night of beautiful views, wandering kangaroos and spectacular landscapes. In the company of Liz Bonnin and with Aussie outback astronomer Greg Quicke as their guide to the southern sky, they reveal how the apparently monochrome sky at night is in fact a riot of glorious colour.Brian and Dara also reveal how Australia, which faces directly into the heart of our Milky Way galaxy, is in the front line when it comes to protecting our planet - whether it be from the threat of a giant asteroid impact or from contact with alien life. And we hear how the Aussie outback contains secrets that Nasa hope will lead them to alien life on Mars.And will viewers have managed to find the elusive missing ninth planet in our solar system?