The Gist Thanks to the James Webb Telescope, scientists recently discovered a “super-Earth,” a planet nearly twice the size of our Earth that is also likely to harbor life. That would be 124 light years away from us.
James Webb never ceases to amaze us. The nearly $10 billion space telescope has allowed researchers to discover a new exoplanet, a “super-Earth” larger than our beloved blue planet. Call it “K2-18b”. It is located almost 124 light-years from our planet, in the constellation Leo, around a so-called “red dwarf,” a star almost half the size of our sun.
Also read:
A giant leap for astronomy! The James Webb Telescope captures the light of a near-Earth exoplanet for the first time
According to scientists, “K2-18b” would be a “super-Earth,” that is, a planet that is not only in the “habitable zone” of its system, but is also larger than our Earth, about two and a half times. A study based on data collected by NASA and the European Space Agency (ESA), published on Monday, September 11, announces that researchers have managed to detect methane and carbon dioxide molecules on its surface. The presence of these two gases therefore suggests that “K2-18b” may have a hydrogen-rich atmosphere and oceans on its surface: in short, the essential ingredients of life.
An ocean on its surface?
This type of exoplanet is called a “Hycean planet” or “Hyceanic”. The term is derived from the English word “hycean”, which represents a contraction of hydrogen and ocean. This is a very new term and a very new research topic for researchers. For several years, Nikku Madhusudhan and his teams at the University of Cambridge have defined eleven exoplanets as “Hycean,” and according to them, “K2-18b” appears to be the one whose atmosphere is most conducive to the emergence of life.
Also read:
New molecule discovered by James Webb Telescope: “A unique scientific moment for understanding the birth of planets”
“The abundance of methane and carbon dioxide, as well as the scarcity of ammonia, support the hypothesis that there may be an ocean beneath the hydrogen-rich atmosphere of K2-18b,” the researchers explain in their study. And the analysis doesn’t stop there! Dimethyl sulfide molecules were reportedly detected on the surface of “K2-18b.” This discovery still needs to be “confirmed,” the researchers say, but this type of molecule is a light sulfur compound that is generally found in a variety of foods: they are generally produced by phytoplankton in marine environments.
“Our understanding of our place”
These discoveries are all the more remarkable because the search and study of exoplanets is particularly sensitive. This requires particularly powerful instruments. There are several methods: one of them is to analyze the fluctuations in brightness of a star to understand which celestial objects are in orbit. James Webb, for his part, made these maneuvers possible: “One transit observation with Webb provided a precision comparable to eight observations with the old Hubble telescope,” the scientists explain.
Also read:
James Webb Telescope: Olivier Berné from Toulouse talks about the extraordinary scientific adventure in the heart of the Orion Nebula
“Our ultimate goal is to identify life on a habitable exoplanet, which would transform our understanding of our place in the universe,” concludes Madhusudhan. “Our results represent a promising step toward a deeper understanding of the Hycean worlds in this search.”