Earth might one day soon resemble the planet Venus.

Perhaps one day I will go into space.

Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill.

I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet Earth.

I'm not promising to write 'JFK 2' - but one day, I might!

There are too many accidents that can befall life on a single planet.