Most likely number of alien worlds is 36

Anybody there? Humans have been searching space for signs of life for over 100 years. © Alamy

Will we ever meet aliens? According to a recent calculation, it is very probable that other life exists somewhere in the Universe – but it could be too far away for us to get in contact.

What’s happening

The scientist listened in awe as his radio stopped its usual crackle and made an odd, repetitive sound. He was convinced it was a message from Martians.

Nikola Tesla was one of the first people to use radio signals to look for extraterrestrial life. Over a century on, we are still searching.

Find out more

New research has suggested there could be more than 30 intelligent alien civilisations for us to find. Scientists in Nottingham made the estimate by looking at how evolution occurred on Earth.

Humans began communicating 4.5 billion years after Earth was created. The scientists guessed it would take a similar amount of time for aliens to evolve on a different planet. Knowing this, they counted all the stars in the Milky Way that were possible homes for intelligent life. The most likely number was 36.

Signs of life could offer a glimpse into how long human civilisation could last on Earth. Christopher Conselice, who worked on the study, said that, by searching for aliens, “we are discovering our own future and fate”.

Will we ever meet aliens?

Some say…

Yes! It is fairly probable that life does exist elsewhere in the Universe. Some researchers even think simple bacteria could be growing on Jupiter’s moons. Back in 1896, when Nikola Tesla was searching for aliens, all he had was a radio. Now, technology is developing so fast that we could soon have the ability to make contact with intelligent life.

Others think…

It seems unlikely. Any intelligent life existing outside our solar system is too far for human spacecraft to travel. Even if we developed a rocket that could take us that far, we probably would not survive the trip. Besides, there is no guarantee that other civilisations would wish to communicate with us – they might be afraid or worse, attack.

You Decide

  1. Would it be better to go to an alien planet or travel in time?


  1. Invent an alien you would like to meet and draw it. Make up a word for “hello” in its language.

Some People Say...

“To my mathematical brain, the numbers alone make thinking about aliens rational. The real challenge is to work out what aliens might actually be like.”

Stephen Hawking (1942-2018), British physicist

What do you think?

Word Watch

A feeling of great respect, sometimes mixed with fear.
Inhabitants of the planet Mars.
Nikola Tesla
Elon Musk named his electric car company after this inventor born in 1856.
Something that exists beyond Earth.
Intelligent alien civilisations
Similar to humans and capable of communication.
A rough guess based on some evidence.


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