This artists principle reveals what exoplanet K2-18 b could look like based on science data. K2-18 b, an exoplanet 8.6 times as huge as Earth, orbits the cool dwarf star K2-18 in the habitable zone. Image credits: NASA.
In 2015, the Kepler Space Telescope discovered a quite fascinating planet. The planet, called K2-18 b, was thought to be a mini-Neptune orbiting a red dwarf (smaller than the Sun), some 134 light years away.
How right they were!
Water and life.
Water is our best link to life as we understand it. Without water, life cant exist (or we do not think it can exist). Water also can just exist under extremely particular temperature conditions. Scientists are very first looking for planets that fall within the temperature variety that can support water; then theyre looking for indications of water itself.
Quick forward to 2023, and NASA puts out a news release of a JWST (James Webb Space Telescope) research study, stating that the planet “could be a Hycean exoplanet, one which has the potential to possess a hydrogen-rich environment and a water ocean-covered surface.” Thats pretty cool, however several media reports speculated and jumped the gun about JWST finding indications of life
For now, thats absolutely nothing more than speculation.
So, whats the handle the mini-Neptune K2-18 b?
” We demonstrate that atmospheric NH3 depletion is a natural consequence of the high solubility of nitrogen types in magma at decreasing conditions, exactly the conditions dominating where a thick hydrogen envelope is in interaction with a molten planetary surface,” the authors of the previous study compose. So, we may effectively be observing oceans of lava rather of water.
Well, the previous research study concluded that K2-18 b probably has oceans. The paper is entitled “Distinguishing oceans of water from magma on mini-Neptune K2-18 b,” so oceans of lava are another possibility.
Even with the brand-new JWST observations, K2-18 b is still quite a puzzle. Its density is someplace in between Neptunes and Earths and were not truly sure what its made from. In fact, it might have a variety of different structures. The most crucial idea that JWST brings is that it has an atmosphere thats rich in carbon and bad in ammonia. These observations both fit with the concept of an ocean world with a thick hydrogen/helium atmosphere.
But what if the world looked more like this? Image produced by AI based on a lava world description (Dall-E 3).
However they likewise fit with the concept of a lava world.
No signs of life?
Far, the world is pretty appealing. The article mixed in a bit of speculation, took a couple prices estimate out of context, and recommended that we may be well on the method to finding aliens– if we havent currently.
So ends up something I said in a YouTube video has been gotten on by UFO lovers & & then bizarrely the @spectatorI said that in 2024 we might see a claim of a biosignature discovered in the environment of an exoplanet with JWST. This was simply a enthusiastic and enthusiastic guess. https://t.co/RH3EFR04iK— Dr Becky Smethurst (@drbecky_) January 17, 2024
If you desire a clue about just how taken out of context this is, heres a tweet from Dr. Becky Smethurst, one of the individuals priced quote in the short article, about how she disagrees with the articles viewpoint.
However, this being stated, K2-18 b is actually fascinating for various reasons.
At the end of the day, neither NASA nor ESA, not JWST nor any other observatory or company has discovered signs of aliens– and K2-18 b is definitely not in the discussion.
Back to actual science: Hycean exoplanets
However, for that to occur, astronomers need to very first determine whether the oceans are indeed water– or lava. In order for that to take place, we require more data and more observations.
” Our findings highlight the value of thinking about varied habitable environments in the search for life elsewhere,” discussed Nikku Madhusudhan, an astronomer at the University of Cambridge and lead author of the paper revealing the JWST results. “Traditionally, the look for life on exoplanets has focused mainly on smaller sized rocky planets, but the larger Hycean worlds are substantially more conducive to atmospheric observations.”
Even with the new JWST observations, K2-18 b is still rather a puzzle.
“Developing clear disambiguating atmospheric tracers for the presence of liquid water versus lava oceans is type in our quest of discovering possibly habitable worlds among the exoplanet population,” the 2023 study authors conclude.
K2-18 b, an exoplanet 8.6 times as massive as Earth, orbits the cool dwarf star K2-18 in the habitable zone. The world, called K2-18 b, was thought to be a mini-Neptune orbiting a red dwarf (smaller than the Sun), some 134 light years away. Well, the previous study concluded that K2-18 b probably has oceans. The paper is entitled “Distinguishing oceans of water from magma on mini-Neptune K2-18 b,” so oceans of lava are another possibility.
Hycean worlds are water worlds that have a hydrogen environment (HYdrocen oCEAN planets). Defined by large, deep oceans covering the entire surface area and a thick, hydrogen-rich environment, these worlds are bigger and warmer than Earth but smaller than ice giants like Neptune. This is why K2-18 b is important, due to the fact that it can reveal us whether this type of world in fact exists.
Any planet that can potentially host water is fascinating, as we described earlier. If K2-18 b in fact has water, that makes it a part of an unique class of theoretical planets.