This planet seems to be in such sorry shape. And I can't ever think about the rest of the universe without coming back home and thinking what the implications for life here would be if we were to really have some definitive proof of extraterrestrial life.

I think human self-hatred may be the great untold story of the millennium. It's the common thread linking deep ecology and animal rights, the love and money we lavish on pets, the uneasy longing for extraterrestrials to be meddling with us.

I grew up in Africa, in Nigeria. I never knew, I never had any reasonable encounter with football. I saw football on Sky News. I thought there were people dressed like extraterrestrials, you know, like they were going to Mars or something, headgears and shoulder pads. And I wondered why, as a child, why did they have to dress that way.

As far as I'm concerned, Enceladus has become the go-to place in our solar system for issues bearing on extraterrestrial life. It's a great place to examine extraterrestrial organic chemistry that is water-based and, therefore, like biotic chemistry on Earth.

I don't believe in a conspiracy to hide the existence of extraterrestrial life.

Among the radio astronomers of SETI - the Search for Extraterrestrial Intelligence - it's only sort-of a joke that the true hallmark of intelligent life is the creation of radio astronomy.

Among the plausible niches for extraterrestrial life in our solar system, the clouds of Venus are among the most accessible and the least well explained.

I prefer to speak of 'interdimensionals' rather than 'extraterrestrials' because the latter has connotations of 'little green men' and all the other cliche responses. Nor does it tell the full story.

Within the scientific community, there is healthy skepticism. And the question is, 'How do you ever get to a meaningful null result? How long and how hard do SETI scientists have to look for extraterrestrial intelligence and find nothing before they say, 'There is nothing. We are alone.'

The pulsar map is not dangerous at all. It will likely never even be seen by extraterrestrials.