First contact
Is there life somewhere else in the universe? This is one of the biggest mysteries of all. Humans have searched for the answer for thousands of years, but have never found any evidence of lifeforms on other planets. If intelligent life (living things that can communicate like us) exists, some people want to talk with the aliens so that we can learn from them. Other people say that could be a bad idea, if the extraterrestrials (another word for aliens) were unfriendly. However, what if instead of humans finding aliens, they find us? That’s what happens in a new film, Elio, where an 11-year-old boy accidentally becomes the intergalactic ambassador of planet Earth.
Searching for signs of life
In an attempt to communicate with any civilisation in our galaxy, scientists have broadcast messages to space. This is a field of research known as SETI (Search for Extraterrestrial Intelligence). Scientists have also sent physical items, such as a pair of Golden Records on board the two Voyager space probes, which were launched in 1977. These discs contained music and images that show the sights and sounds of Earth. This type of signal is called a “message in a bottle” – a message released to travel through space in the hope that one day it will be picked up. Some people argue that broadcasting our presence with this type of signal is dangerous, whereas others believe silence is pointless – if aliens are advanced enough to send us a message then they already know we are here.
In 1977, a powerful radio burst now known as the Wow! Signal got astronomers excited. Lasting 72 seconds, the signal was so unusual that astronomer Jerry Ehman wrote “Wow!” next to the print-out. What’s even more unusual is that the signal was never repeated and experts haven’t been able to fully explain it. Could it have been an alien civilisation trying to say hello?
Decoding messages
Even if we were to receive a signal, would we be able to understand it? People on Earth often struggle to understand each other and the meaning of some things can be lost to history. How would we decode a message from an entirely different species?
Some things in space are universal, like physics and elements. They could act as keys to decode any messages. The Voyager golden records used a hydrogen atom as the key to decode and play the records. Linguists (language experts) might look for patterns within messages to try and understand them, too.
There are tools currently being used elsewhere that might also be able to help. People at CETI (Cetacean Translation Initiative) and DolphinGemma have been successful in using artificial intelligence and machine learning to understand dolphins. This technology could be used to translate alien speech.
Writing a reply
In films, first contact with aliens often goes either very well or very badly. First impressions are important. Luckily, there is a plan in place if aliens were ever to get in touch with us. Astronomer and SETI scientist Seth Shostak helped write the plan and told us what it was on the Mysteries of Science podcast. The key elements are to stay calm, verify the signal, inform the world, and only reply if there is global agreement. Radio signals in space take a long time to travel, so there might be decades between messages.
There are currently no signs of alien life elsewhere in the universe – but if it does exist it might only be a matter of time before first contact takes place. Whether we understand it when it does and how we respond will change our view of life for ever.
Also
Most space science focuses on listening for signals. We use radio waves to understand how galaxies move and how black holes behave. “Active SETI” is the name given to a group of people who want to broadcast to the universe. There have been attempts in the past. The Arecibo Message in 1974 was the most powerful signal to be sent, and it is considered to be the most serious attempt. Supporters of active-SETI say it’s the biggest and most important step to making contact. It might also be a way to share our culture and findings with others in case humankind one day goes extinct. Others say that it’s risky. Even the famous scientist Professor Stephen Hawking suggested that broadcasting into space could attract trouble.
First published in The Week Junior Science+Nature, issue 89, June 2025.