Scientists discover new technique that could find hidden aliens

New approach could identify life forms we might have entirely missed otherwise

Andrew Griffin
Wednesday 24 January 2018 20:00
Comments
Scientists discover new technique for finding hidden aliens

We might have just found an entirely new way of spotting aliens.

Scientists have proposed a new way of looking out for marks of aliens in the universe. And it could help us see life forms we'd completely miss otherwise.

Space agencies including Nasa have been active in launching new tools to study the universe, such as the James Webb Telescope. That will provide information on the atmospheric makeup of planets far away – but we might not be sure how to use that information.

Until now, scientists have mostly been looking for oxygen in the atmosphere. If that's found, then it's likely that there's the chance for life on that planet, since we know from life on Earth that oxygen is key.

But we might be missing other important markers – known as biosignatures – that could indicate such worlds are supporting life. As such, planets might have life on them that we wouldn't spot using just oxygen.

"This idea of looking for atmospheric oxygen as a biosignature has been around for a long time. And it's a good strategy -- it's very hard to make much oxygen without life," said Joshua Krissansen-Totton, an author on the paper published in Science Advances. "But we don't want to put all our eggs in one basket. Even if life is common in the cosmos, we have no idea if it will be life that makes oxygen. The biochemistry of oxygen production is very complex and could be quite rare."

To do the research, the scientists looked at the history of life on Earth, and the kinds of gases that were around when it was. They found that the planet had a complex mix of different gases, not only oxygen, and that looking for that cocktail could be a far more reliable marker of life on a planet.

"We need to look for fairly abundant methane and carbon dioxide on a world that has liquid water at its surface, and find an absence of carbon monoxide," said co-author David Catling, a UW professor of Earth and space sciences. "Our study shows that this combination would be a compelling sign of life. What's exciting is that our suggestion is doable, and may lead to the historic discovery of an extraterrestrial biosphere in the not-too-distant future."

The scientists explored how a planet could have an imbalance of methane, including possible events like asteroid impacts or rocks interacting with water. But they found it would be very difficult to produce a lot of the gas on a rockey, Earth-like planet – unless it had living organisms on it.

The processes that generate both methane and carbon dioxide, such as big volcanic eruptions, would also tend to produce carbon monoxide alongside them. But carbon monoxide would be eaten up by microbes living on those planets.

"So if carbon monoxide were abundant, that would be a clue that perhaps you're looking at a planet that doesn't have biology," said Mr Krissansen-Totton.

That means that if we were able to find methane and carbon dioxide on planets that didn't have much carbon monoxide, it could be a good way of spotting aliens even at some distance away, they said.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged in