"There are two trillion galaxies in the observable Universe and I find it impossible to imagine that there are no other civilisations,” scientist and TV presenter Brian Cox tells The Week Junior, speaking ahead of his appearance at Starmus festival (17–22 October). Despite this, it seems that evidence of alien life has not been found yet. This lack of proof is called the Fermi Paradox. Some scientists think it shows that it’s very difficult for complex life to emerge, and that life on Earth is a special case. Nevertheless, lots of people report seeing flying saucers. Many are hoaxes (fake) but footage has been released by the US government showing pilots’ encounters with unexplained objects. So what do you think? Will humans find aliens? Or are we alone in the Universe?
Yes – we’ll come across aliens eventually
It’s hard to believe that life only exists on Earth. It took a billion years before life emerged on our planet, and it could have evolved elsewhere many times throughout the 13-billion-year history of the Universe. Scientists think they have already identified several planets that have water, an atmosphere and aren’t too hot or cold. Saturn’s moon Enceladus and Jupiter’s moon Europa seem to have conditions that could host life in oceans beneath their surfaces. In 2025, NASA found minerals on Mars that, on Earth, are made by microbes such as bacteria. If simple life can emerge on other planets, it could evolve into complex life. Eventually, intelligent life could emerge, just like it did on Earth. Sooner or later, humans will come across it.
No – there would be evidence by now
If life was common throughout the Universe, surely we would have seen some signs of it. Maybe life on Earth is a lucky one-off. Besides, many scientists think that if there’s any life out there, it’s more likely to be simple organisms such as bacteria. If humans haven’t managed to find even basic life, then encountering advanced civilisations, little green men and flying saucers seems very unlikely. Also, the distances to other solar systems are too vast. “My guess is that the nearest civilisation will be so far away that we will never make contact with them,” says scientist Brian Cox. Distance aside, the Universe is billions of years old – so even if alien civilisations had emerged elsewhere, they might be extinct already.
By submitting a comment, you and your grown-up are telling us that:
✔️ the comment is your own - you made it, or someone has said you can share it;
✔️ using it won't break anyone else's rules or rights; and
✔️ it is ok for us to edit the comment for length, accuracy and suitability
If you have any questions, ask a grown-up to email us.
For grown-ups: "we"/"us" means Future Publishing Limited (company number 02008885), the publisher of The Week Junior and Science & Nature and part of the Future plc group. More about Future.