Scientists Find Hint of Life on Super-Earth 120 Light-Years Away

The James Webb Space Telescope has observed a faint marker of potential life on a super-Earth 120 light-years away. It doesn't prove life exists there, scientists say. Yet the finding is significant. 

A University of Cambridge research team performed the study. The team published its findings in the Astrophysical Journal Letters. The team performed the same analysis many times on the planet K2-18b. (It's in the Leo constellation.) The team found the planet's atmosphere might contain a rich supply of two molecules that have only one source: living things. The team believes that K2-18b has either dimethyl sulphide or dimethyl disulphide, or both.    

Bacteria and ocean phytoplankton produce these gases on Earth. K2-18b is 2.5 times larger. It orbits a cooler red dwarf star.  What do the possible presence of these gases on K2-18b suggest? It could be a world that's warm and covered by an ocean. It could also have an atmosphere rich in hydrogen.    

How did the research team arrive at this theory? They studied the small amount of changing-colored starlight that reaches the atmosphere. It was observed by the Webb telescope.  

One of the study's authors is Nikku Madhusudhan. He's a Cambridge astronomer. He said that it is too early to conclude life exists on K2-18b. But he added that this is the first time potential markers of life have been observed on a distant planet. He called it “a revolutionary moment.”

Other scientists, including some who have worked with him, were more doubtful. Sara Seager is a MIT professor and his former graduate adviser. Seager told the Atlantic magazine that “enthusiasm” about life on K2-18b “is outpacing evidence.” More research is needed, Seager and others say. 

“I’m not screaming, ‘aliens!’” Nikole Lewis, a Cornell University astrophysicist, told The New York Times. “But I always reserve my right to scream ‘aliens!’”   

Reflect: If you could explore any planet in the universe, what would you want to discover there, and why?

Photo of illustration Exoplanet K2-18 b from Wikimedia Commons courtesy of NASA, ESA, CSA, Joseph Olmsted.