Some claim that computers will, by 2050, achieve human capabilities. Of course, in some respects they already have.

To most people in the UK, indeed throughout Western Europe, space exploration is primarily perceived as 'what NASA does'. This perception is - in many respects - a valid one. Superpower rivalry during the Cold War ramped up US and Soviet space efforts to a scale that Western Europe had no motive to match.

I suspect there could be life and intelligence out there in forms we can't conceive. Just as a chimpanzee can't understand quantum theory, it could be there as aspects of reality that are beyond the capacity of our brains They could be staring us in the face and we just Don't recognise them. The problem is that we-re looking for something very much like us, assuming that they at least have something like the same mathematics and technology.

I hope that by 2050 the entire solar system will have been explored and mapped by flotillas of tiny robotic craft.

Devastation could arise insidiously, rather than suddenly, through unsustainable pressure on energy supplies, food, water and other natural resources. Indeed, these pressures are the prime 'threats without enemies' that confront us.

God invented space so that not everything had to happen in Princeton.

The carbon dioxide concentration in the atmosphere is measured. It's uncontroversial. It's going up. We know that has a tendency to warm the atmosphere and we should be worried about that.