Exploring The Planets

Brian Cox reveals highlights from his BBC Two series The Planets and discusses the future challenges of Solar System exploration

We tend to think of our Solar System as a sort of fossilised remnant, but it was dynamic and planets were moving about a lot in the early years. What’s been remarkable over the past decade is the amount of detail we’ve been able to put into the story of the Solar System, mainly driven by planetary exploration.

When we were making Wonders of the Solar System,

which aired in 2010, Cassini had only just arrived at Saturn. In this new series we explore ideas like the Grand Tack model, which is a very recent development; another is that Mercury almost certainly formed farther from the Sun. We’ve now seen well over 3,000 planets around distant stars and know the layout of other systems is not like our own.

There’s an underlying philosophy to the series, that the Solar System is a ‘system’. I think it’s quite natural for us to think we’re isolated from the rest of the Universe, but understanding the way Mars and Venus have evolved, that atmospheres of planets can change, teaches us we as a species are fortunate, but in a rather precarious position.

Some of the biggest questions are in astrobiology, which we deal with in this series. It’s that question: ‘Is there life?’ Particularly on Mars or some of the icy moons. That’s what NASA’s upcoming Europa Clipper mission is designed to look at on Jupiter’s moon Europa. In one episode we focus on Titan, which is a planetary sized moon with a thick atmosphere and complex organic chemistry. There’s a plan to put a helicopter drone onto it.

We’ve completed the initial reconnaissance of the Solar System, but only flown past Uranus, Neptune and Pluto. I’d like to see an orbiter around Neptune in particular, although it’s difficult to do.