SubNeptune planet K2-18b shows methane and dimethyl sulfide

[DaveC426913]

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

 

[DennisN]

Very thrilling and exciting!

 

[Cerenkov]

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.

 

[Vanadium 50]

Stinky.