Astronauts have been stuck in low-Earth orbit, boldly going nowhere. American attempts to kick-start a new phase of lunar exploration have stalled amid the realisation that NASA's budget is too small for the job.

When I was a student, the laws of physics were regarded as completely off limits. The job of the scientist, we were told, is to discover the laws and apply them, not inquire into their provenance.

No planet is more earth-like than Earth itself, so if life really does pop up readily in earth-like conditions, then surely it should have arisen many times right here on our home planet? And how do we know it didn't? The truth is, nobody has looked.

Should we find a second form of life right here on our doorstep, we could be confident that life is a truly cosmic phenomenon. If so, there may well be sentient beings somewhere in the galaxy wondering, as do we, if they are not alone in the universe.

Every society, all government, and every kind of civil compact therefore, is or ought to be, calculated for the general good and safety of the community.

To achieve the kinds of innovations needed to tackle the climate crisis, government must not shun the private sector, but rather must work closely with industry and our nation's great research universities.

I've voted in every election - not always for the same political party and never with any degree of enthusiasm.

The federal government has an exceptionally poor record of behaving responsibly with Americans' personal information when entrusted with it.