The Long Dead Stars

I don't look at this timeline much these days, but noticed increased activity with people shouting stuff. I tracked the cause down to reactions to an article promoting my new Solar System series on the BBC website - nice that it has got attention - Monday, 9pm, BBC2 if you are asking ;-) It's fun I hope, and I do some experiments with eggs in the first episode. However, just to be clear: 1) I don't think it is 'probable' that we are the only advanced civilisation in the Milky Way. I have no way of assigning a probability to it. I can make an argument that complex life may be rare, and I think it's a good working hypothesis to assume this in the absence of other evidence, because it might make us value ourselves and our planet more. I certainly think there's a chance we may find simple life on Mars, Europa, Enceladus, Ganymede or even in possible sub-surface water on Pluto or elsewhere. I'm excited for the missions we have planned to explore these worlds. There are of course trillions of planets and moons in the Milky Way, and I'd be very surprised if they were all lifeless. But Civilisations - my guess is a handful at best. Beyond the Milky Way, in the trillions of galaxies in the observable Universe, surely there are other civilisations more advanced than us. 2) I do think that it is important for us to learn how to live and work in space - and the first steps beyond Earth orbit will be the Moon and Mars. HOWEVER (and I ALWAYS say this in interviews on this subject) there is a caveat! There is nowhere else we could go that would replace Earth, and therefore our number 1 priority must be to protect this planet. If we mess this one up, there is nowhere else we could live in large numbers - at least (in my view) for many centuries to come. It is a major error to assume that we can just up sticks and start again. In my lifetime, to paraphrase Carl Sagan, I can only hope we take our first steps into the Cosmic Ocean - the waters seem inviting. 3) I'd love to see Earth from orbit. But - as someone who was born close to Yorkshire - when asked if I'd like to go I always answer the same way. "Yes, if someone else is paying ...."