Even if all life on our planet is destroyed, there must be other life somewhere which we know nothing of. It is impossible that ours is the only world; there must be world after world unseen by us, in some region or dimension that we simply do not perceive. Even though I can't prove that, even though it isn't logical — I believe it.

It’s OK if the world is destroyed,” he said. “There are a thousand million other worlds for us to create and choose from. As long as people want planets, there will be planets to live on.

Life can exist on other planets, in other solar systems, in other galaxies and universes.

There are other worlds and rational beings of a different and higher kind. The world in which we live is not the only one in which we shall live or have lived.

All my life, I've wondered about life beyond the earth. On those countless other planets that we think circle other suns, is there also life? Might the beings of other worlds resemble us, or would they be astonishingly different? What would they be made of? In the vast Milky Way galaxy, how common is what we call life? The nature of life on earth and the quest for life elsewhere are the two sides of the same question: the search for who we are.

The terms we use for what is considered supernatural are woefully inadequate. Beyond such terms as ghost, specter, poltergeist, angel, devil, or spirit, might there not be something more our purposeful blindness has prevented us from understanding?
We accept the fact that there may be other worlds out in space, but might there not be other worlds here? Other worlds, in other dimensions, coexistent with this? If there are other worlds parallel to ours, are all the doors closed? Or does one, here or there, stand ajar?

If there were other people on other planets it would certainly raise theological issues. Further, there is no (zip, zero, nada) scientific evidence of any life of any kind outside of Earth (except maybe angels).

If we're stuck on one world, we're limited to a single case; we don't know what else is possible. Then — like an art fancier familiar only with Fayoum tomb paintings, a dentist who knows only molars, a philosopher trained merely in NeoPlatonism, a linguist who has studied only Chinese, or a physicist whose knowledge of gravity is restricted to falling bodies on Earth — our perspective is foreshortened, our insights narrow, our predictive abilities circumscribed. By contrast, when we explore other worlds, what once seemed the only way a planet could be turns out to be somewhere in the middle range of a vast spectrum of possibilities. When we look at those other worlds, we begin to understand what happens when we have too much of one thing or too little of another. We learn how a planet can go wrong.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.

The Earth is the only world known so far to harbour life. There is nowhere else, at least in the near future, to which our species could migrate. Visit? Yes. Settle? Not yet. Like it or not, for the moment, the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. ... To me, it underscores our responsibility to deal more kindly with one another and to preserve, and cherish, the pale blue dot; the only home we've ever known.

Intelligent life on other planets? I'm not even sure there is on earth!

If we did destroy the planet, it would have irrevocable consequences for the rest of the solar system, and the future for humanity would be dreadful indeed. We would have no planet to live on, and would have perpetrated a terrible crime against ourselves and the other planets. We would end up incarnating on some distant, dark planet, not at all evolved. We would have to start at the beginning, as we were millions of years ago, and take again the long slow climb upwards. It would be unbelievably painful and restrict our evolution for thousands, perhaps millions of years. Why choose that? Why, indeed, choose such an end?

Was there only one world after all, which spent its time dreaming of others?

Was there only one world after all which spent its time dreaming of others?