Can a lack of certain atmospheric characteristics in an exoplanet be a sign of life? This is what a team of international scientists hope to unlock as they discuss a novel strategy for detecting the lack of carbon dioxide in a rocky exoplanet’s atmosphere compared to other planets in the same system and how it could help isolate where to look for life. In a recent study published in Nature Astronomy, the researchers ascertain this investigation could be conducted using data from NASA’s James Webb Space Telescope (JWST) and holds the potential to help astronomers better understand the necessary atmospheric conditions that could be suitable for finding life as we know it throughout the cosmos.
“The Holy Grail in exoplanet science is to look for habitable worlds, and the presence of life, but all the features that have been talked about so far have been beyond the reach of the newest observatories,” said Dr. Julien de Wit, who is an assistant professor of planetary sciences at the Massachusetts Institute of Technology and a co-author on the study. “Now we have a way to find out if there’s liquid water on another planet. And it’s something we can get to in the next few years.”
The researchers postulate a three-step strategy for using JWST in detecting carbon dioxide and ozone in exoplanets residing in the TRAPPIST-1 system located approximately 40 light-years from Earth. This strategy calls for detecting a planetary atmosphere around rocky exoplanets in approximately 10 transits of the parent star, assessing a lack of carbon dioxide within the exoplanet’s atmosphere in approximately 40 transits, and obtaining measurements of the atmosphere’s ozone while comparing this to the lack of carbon dioxide in approximately 100 transits.
“If we see ozone, chances are pretty high that it’s connected to carbon dioxide being consumed by life,” said Dr. Amaury Triaud, who is a Professor of Exoplanetology at the University of Birmingham and lead author of the study. “And if it’s life, it’s glorious life. It would not be just a few bacteria. It would be a planetary-scale biomass that’s able to process a huge amount of carbon and interact with it.”
The TRAPPIST-1 system is a prime target given it possesses seven Earth-sized exoplanets orbiting in a compact arrangement, with some of them hypothesized to be rocky while orbiting within its star’s habitable zone.
Artist depiction of the TRAPPIST-1 system. (Credit: NASA/JPL-Caltech)
How will JWST help ascertain the prospects for finding life on other worlds through the detection of atmospheric carbon dioxide in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: EurekAlert!, Nature Astronomy, Massachusetts Institute of Technology, Wikipedia, NASA JPL
