RESEARCHERS may have uncovered a new method for detecting liquid water on exoplanets.
The scientific findings were published in the journal Nature Astronomy on December 28th.
NASA, ESA, L. Hustak (STScIResearchers may have uncovered a new method for detecting liquid water on exoplanets[/caption]
The study proposes a way to identify exoplanets – a planet that orbits a star outside the solar system – harboring oceans and potentially even hosting alien life.
Currently, finding liquid water on exoplanets is like searching for a needle in a haystack.
Despite discovering over 5,000 exoplanets, it has been difficult for scientists to confirm the presence of water.
While we can sometimes detect water vapor in their atmospheres, pinpointing planets with actual oceans is a different story.
As such, the new study suggests that by comparing the carbon dioxide (CO2) levels of neighboring exoplanets, we can identify potential water worlds.
The key lies in the fact that Earth’s oceans absorb a significant portion of atmospheric CO2.
So, an exoplanet with significantly lower CO2 levels compared to its neighbors could be hiding liquid oceans beneath its surface.
“We know that initially, the Earth’s atmosphere used to be mostly CO2, but then the carbon dissolved into the ocean and made the planet able to support life for the last four billion years or so,” study co-lead author Amaury Triaud, professor of exoplanetology at the University of Birmingham in the U.K., said in a statement.
Because CO2 absorbs infrared radiation as well, scientists can use NASA’s James Webb Space Telescope (JWST) for this technique.
“It’s a really nice way of doing this,” said Sarah Casewell, a lecturer in the school of physics and astronomy at the University of Leicester in the U.K., who wasn’t involved in the research.
“And it’s also not going to involve a massive investment of telescope time, which is really important because that’s extremely precious to our community,” she added.
Another factor that contributes to low carbon is life itself.
That’s because carbon is an organic molecule that is fundamental to the building blocks of life as we know it.
“Despite much early hopes, most of our colleagues had eventually come to the conclusion that major telescopes like the JWST would not be able to detect life on exoplanets. Our work brings new hope,” study co-lead author Julien de Wi.
“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,” de Wit said.