Researchers find new way to identify water and potential life on exoplanets
A team of researchers from multiple countries, including those from the Massachusetts Institute of Technology (MIT) and the University of Birmingham, have discovered a new way to determine whether exoplanets are habitable or potentially inhabited.
The research, published Thursday in Nature Astronomy, shows that if a planet has less carbon dioxide in its atmosphere than its neighbours, it implies the presence of liquid water – the determining factor for habitability.
Researchers say this is likely because the carbon dioxide is being dissolved into an ocean or "sequestrated by a planetary-scale biomass."
The scientists said habitability refers to whether an exoplanet can hold liquid water on its surface. Like Earth, the planet must be a certain distance away from its star, an area described as the "habitable zone" or the "Goldilocks zone."
"Planets too close to their star are too hot (such as Venus), those too far, are too cold (like Mars), whereas planets in the 'habitable zone' are just right," a news release accompanying the research states.
Until this discovery, there had been no practical way to determine a planet's habitability, researchers said, although other scientists had made progress. The release states the previous method of checking for liquid water on exoplanets involved looking for a starlight reflection or "glint."
However, researchers added this signature is hard to detect with currently existing technology.
Amaury Triaud, professor of exoplanetology at the University of Birmingham in the U.K. and co-leader of the research team, said this new method can be used right away.
"It is fairly easy to measure the amount of carbon dioxide in a planet's atmosphere. This is because CO2 is a strong absorber in the infrared, the same property causing the current rise in global temperatures here on Earth.
Triaud said scientists already know that the Earth's atmosphere used to be made up of mostly carbon dioxide until it dissolved into the ocean, allowing the planet to support life. He added studying carbon dioxide in other planets may provide insight into the point at which carbon levels make a planet uninhabitable.
"For example," Triaud said, "Venus and Earth look incredibly similar, but there is a very high level of carbon in Venus' atmosphere. There may have been a past climatic tipping point that led to Venus becoming uninhabitable."
Julien de Wit, assistant professor of planetary sciences at MIT and co-leader of the study, said the new method can also be used as a biosignature, or evidence of a biological process.
"One of the tell-tale signs of carbon consumption by biology, is the emission of oxygen. Oxygen can transform into ozone, and it turns out ozone has a detectable signature right next to CO2. So, observing both carbon dioxide and ozone at once can inform us about habitability, but also about the presence of life on that planet," de Wit said.
He also emphasized the importance of being able to check for carbon dioxide levels in exoplanets with current telescopes.
"Despite much early hopes, most of our colleagues had eventually come to the conclusion that major telescopes like the JWST (James Webb Space Telescope) would not be able to detect life on exoplanets. Our work brings new hope," de Wit said.
"By leveraging the signature of carbon dioxide, not only can we infer the presence of liquid water on a faraway planet, but it also provides a path to identify life itself."
RISKIN REPORTS
CTVNews.ca Top Stories
BREAKING Czechia scores late to eliminate Canada from world juniors
Jakub Stancl scored his second goal of the game with 11.7 seconds left in third period as Czechia survived a blown 2-0 lead to defeat Canada 3-2 and advance to the semifinals at the world junior hockey championship on Tuesday.
Canadian couple lives on cruise ships — with no plans to return to land
With 75 countries and territories visited, a retired Canadian couple is making the most of life as they cruise full-time, from coast to coast. They're part of a growing trend of people opting to retire at sea.
Planes catch fire after a collision at Japan's Haneda airport, killing 5. Hundreds evacuated safely
A passenger plane and a Japanese coast guard aircraft collided on the runway at Tokyo's Haneda Airport on Tuesday and burst into flames. Transport Minister Tetsuo Saito confirmed that all 379 occupants of Japan Airlines flight JAL-516 got out safely before the plane was entirely engulfed in flames.
Blast shakes Beirut's southern suburbs as tensions rise along the border with Israel
An explosion shook the Lebanese capital's southern suburbs Tuesday evening causing chaos in the militant Hezbollah group's stronghold, but the nature of the blast was not immediately known.
A missing person with no memory: How investigators solved the cold case of Seven Doe
Police specializing in missing people and cold cases have discovered the identity of a woman with no memory in one of the most unusual investigations the sheriff's office has pursued and one that could change state law.
Weight-loss drugs: Who, and what, are they good for?
Extraordinary demand, and high prices, for powerful weight-loss drugs will keep them out of reach in the coming year for many patients who are likely to benefit.
Woman who fell out of Edmonton city bus dies
A woman who fell out of an Edmonton city bus Friday has died, police said in a media release issued Monday.
Canada's 100 highest-paid CEOs broke new compensation records in 2022: report
Canada's 100 highest-paid CEOs broke records with their compensation in 2022, according to the Canadian Centre for Policy Alternatives.
Russian missiles hit Ukrainian cities, killing 5 and injuring almost 100, Kyiv officials say
Ukraine's two largest cities came under attack from Russian hypersonic ballistic missiles on Tuesday morning, killing at least four people and injuring almost 100, officials said.