(01-19-2024 09:02 AM)stinkfist Wrote:  https://www.chron.com/news/space/article...367055.php

Quote:NASA's James Webb Space Telescope has detected the possible presence of a molecule on the exoplanet K2-18 b that, on Earth, is only produced by life. Dubbed dimethyl sulfide (DMS), the molecule is a smell of the sea that is mostly found in Earth's atmosphere and is emitted by phytoplankton in marine environments. "Upcoming Webb observations should be able to confirm is DMS is indeed present in the atmosphere of K2-18 b at significant levels, said Nikku Madhusudhan, an astronomer at the University of Cambridge in a statement.

The discovery was made as scientists analyzed the amount of starlight passing through K2-18 b's atmosphere as its orbit brought the exoplanet between its host star and Webb. The starlight's passage through K2-18 b's atmosphere left traces that allowed scientists to detect a drop in brightness and piece together the exoplanet's gaseous composition. Located 120 light-years away from Earth in the constellation Leo, K2-18 b orbits the cool dwarf star K2-18 in the habitable zone, a region around a star where planets with liquid water may be present. With a radius 2.6 times the radius of Earth, the exoplanet is 8.6 times the size of our planet. Its large size means its interior likely contains a large mantle of high-pressure ice.

Spectra of K2-18 b displays an abundance of methane and carbon dioxide in the exoplanet's atmosphere, as well as a possible detection of a molecule called dimethyl sulfide (DMS).
Spectra of K2-18 b displays an abundance of methane and carbon dioxide in the exoplanet's atmosphere, as well as a possible detection of a molecule called dimethyl sulfide (DMS).

Scientists also discovered carbon-bearing molecules, including an abundance of methane and carbon dioxide, along with a shortage of ammonia in K2-18 b's atmosphere. The new findings support recent studies suggesting that K2-18 b could be a Hycean exoplanet—or a hypothetical planet with a hot, ocean-covered surface hiding beneath a hydrogen-rich atmosphere. However, NASA noted that the ocean could be too hot to be habitable or be liquid.

The findings are a result of just two observations of K2-18 b, said team member Savvas Constantinous of the University of Cambridge in a statement, adding: "This means our work here is but an early demonstration of what Webb can observe in habitable-zone exoplanets."

The team plans to conduct follow-up research using Webb's Mid-Infrared Instrument spectograph to further validate findings and give new insights on K2-18 b. "Our ultimate goal is the identification of life on a habitable exoplanet, which would transform our understanding of our place in the universe," said Madhusudhan. "Our findings are a promising step towards a deeper understanding of Hycean worlds in this quest."

The ocean-scented K2-18 b isn't the only strange exoplanet scientists have come across. Last year, scientists at the Kitt National Observatory in Arizona discovered TOI-3557, a massive and unusually fluffy planet akin to a marshmallow located 580 light-years away from Earth.