SubNeptune planet K2-18b shows methane and dimethyl sulfide

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The investigation using NASA’s James Webb Space Telescope has confirmed the presence of methane and carbon dioxide in the atmosphere of the exoplanet K2-18b, which is 8.6 times the mass of Earth. The findings suggest a potential water ocean beneath a hydrogen-rich atmosphere, supported by the scarcity of ammonia. Additionally, a possible detection of dimethyl sulfide (DMS) raises intriguing questions about the potential for life, as DMS is primarily produced by marine phytoplankton on Earth. The discussion also touches on the tidal locking of K2-18b, with its orbital period of 32.940 days prompting inquiries about its distance from its host star.

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TL;DR
SubNeptune planet 120ly away shows presence of molecules associated with life
"A new investigation with NASA’s James Webb Space Telescope into K2-18 b, an exoplanet 8.6 times as massive as Earth, has revealed the presence of carbon-bearing molecules including methane and carbon dioxide.
...
The abundance of methane and carbon dioxide, and shortage of ammonia, support the hypothesis that there may be a water ocean underneath a hydrogen-rich atmosphere in K2-18 b. These initial Webb observations also provided a possible detection of a molecule called dimethyl sulfide (DMS). On Earth, this is only produced by life. The bulk of the DMS in Earth’s atmosphere is emitted from phytoplankton in marine environments."

https://www.nasa.gov/goddard/2023/webb-discovers-methane-carbon-dioxide-in-atmosphere-of-k2-18b
 
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Very thrilling and exciting! :smile:
 
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Raises an eyebrow, a la Mr. Spock. "Fascinating!"Seriously though, do we have enough data on the exoplanet's mass, it's host star's mass and their separation to know whether K2-18b is tidally locked?

From popular science articles I've read (Sky & Telescope, I think) tidal locking is a problem for exoplanets orbiting red dwarves because these systems tend to be far more compact than our, more extended retinue of planets.

https://en.wikipedia.org/wiki/TRAPPIST-1

Several of the planets in the Trappist-1 system are expected to be tidally locked and I note that the outermost has an orbital period of 18.772 days. The cited period for K2-18b is 32.940 days. I wonder if that's sufficiently distant to place it outside of the tidal locking zone?

Any thoughts?Thank you,

Cerenkov.
 
Stinky.
 
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