The discovery of a new planet outside our solar system, which has a good chance of sustaining life, increases the possibility that there might yet be aliens somewhere out there. Extra-terrestrials have of course long been a mainstay of popular culture, thanks to film, TV and books, while stories of alien abduction continue to pop up from time to time. And the existence – or not – of otherworldly life forms is a subject which continues to fascinate people.

So, this week we're asking:

• Are we really alone in the Universe?

• Do you believe there is life on other planets?

• If aliens landed on earth, how would you greet them?

• Why would aliens want to visit earth?

• If extra-terrestrials do exist, what do you imagine they look like?

• If there are aliens out there, how come they haven't paid a visit to earth yet?

• Can you envisage a time when humans may colonise another planet?

• Have you ever spotted what you believe to be a UFO?

• Do you believe stories of alien abduction or is it a load of old nonsense?