Have scientists discovered life on another planet? Expert signature report on bombshell creatures
Last week, researchers using the James Webb Space Telescope (JWST) announced that they had discovered something interesting to find on distant external exoplanets, called K2-18 B:dimethyl sulfide (DMS), a molecule that is produced almost by microscopic marine organisms on Earth. An external star located about 120 light-years in the habitable area of the Red Dwarf Star, probably the world of the Maritime World: a planet covered with a hydrogen atmosphere of steam.
While the detection has statistical confidence (very promising, but not certain), headlines around the world buzz with speculation about the first discovery of life outside the planet. But not everyone believes it. Interdisciplinary scientists are now on the weight line – some are cautiously optimistic about the latest research, while others are deeply skeptical. Can DMS be a sign of life, or a weird, non-biochemical occurrence that happens under extreme conditions?
For the latest GIZ proposals, we have already made the discovery, research chemistry, limitations of data, and what it takes to transfer the needle from “maybe” to something more explicit. Because in astrobiology, Interesting and Extraordinary It's a thin razor. The following responses are edited and condensed in detail for clarity.
Oliver Shorttle
A planetary chemist at the University of Cambridge has studied the potential habitability of planets.
I have been working hard to develop an understanding of the climate and structure of K2-18b (i.e., the size and temperature of the atmosphere, the foundations of the atmosphere, etc.).
I don't think the report of DM in the K2-18 B spectrum will move the astrobiological needle. A series of steps we have seen signs of life outside of Earth are roughly:
- Establishing the signal is actually the planet seen (in this case, absorption from light passing through the planet's atmosphere)
- The establishment signal is attributed to the biosignature of interest (in this case, molecular absorption in the spectrum from the DMS).
- Excluding non-biological processes can generate biosignatures.
- The rule in (assuming) biological processes is the ability to generate biosignatures.
K2-18 B test has not passed 1 or 2 yet, because the community needs to confirm that it has a signal. This is not my expertise.
3 and 4 are closer to my expertise. Here, K2-18 B presents a special challenge to life. Currently, the planet has data on liquid water oceans and life-friendly climates, and there are no requirements yet. In fact, based on the data, there is good reason to believe that the climate is too hot for a liquid water ocean, and the deep atmosphere may be covered in the ocean of magma rather than liquid water. So even if 1 and 2 return DMS detection, our expectation should be [molecule] Already appearing in the lifeless, heat, sulfur and hydrogen-rich atmosphere and asking yourself what kind of atmospheric chemical reaction this will make. Instead, thinking that this is a biologically sourced DM will need to overturn every expectation of the planet's climate without any other reason to do this from the data.
In other words, we are a long way from thinking we can live in K2-18 B, let alone living.
Christopher Glein
geochemists at the Southwest Institute, and experts who study the possibilities of alien life in the ocean world.
This is a very interesting new dataset. It appears that there are unexplained features in the spectrum of K2-18 B, which may be attributed to dimethyldimethyl or dimethyldisulfide sulfide. However, these results extend JWST to its limits (K2-18 B is a fairly small planet), and further analysis may find that these features lack statistically significant evidence. In this case, we need more astronomers! Currently, I am cautious about the potential existence of these molecules on K2-18b.
Even if DMS or DMD exists, we must be very careful to consider it as a biosignature. We just started asking questions about the abiotic background of this planet. Exotic chemistry may surprise us because the planets are more complex (very interesting) than we assumed in the first place. For lifelong, multiple supporting evidence must be found, which will take time. Let's digest these new results and start working.
My preprint includes an important finding cited below:
“Because the revised depth layer scenario can accommodate exhausted CO [carbon monoxide] and NH3 [ammonia] Abundance, obviously, these species should no longer be used as evidence against this situation in TOI-270D [a planet orbiting another red dwarf, discovered in 2019] and similar planets, such as K2-18b. Our results show that Hycean assumes that no data is currently required, although this does not rule out the existence of Hycean Worlds. ”
Nikku Madhusudhan
astrophysicist at the University of Cambridge and lead author of recent research.
Needle is more direction than before, but we need to be very cautious and open up other possibilities.
I think what we should be most excited about is that we have any data to start and even discuss the possibilities. I think more data
Better constraints should be provided over the next 1 to 2 years.
Ingas Snellen
Astrophysicist at Leiden University and an alien planet expert.
The whole thing was completely blown away. Sorry, my answer is a bit short, but I have had to deal with this in the Dutch and Belgian media over the past two days and I have done some work.
The team found their spectrum bumps. It is not clear whether they are real or not, if so, they may be caused by them. There may be dozens of molecules (if true), and there may even be cloud characteristics. What does the author do? They just see if the DMS can cause this (and add DMD). They ignore dozens of other species [i.e. non-biological sources of molecules] This can cause this bump and call it a day. If I had been a referee, I would have stopped this publication there. There is no reason to call astrobiology, let alone call it the biggest breakthrough.
Most journalists are writing an article and they say “But not all scientists convince…” I can tell you that this is worse than this, but most of us shut up. I understand why during these difficult times, but in the long run, this hurts astronomy and no one will take us seriously anymore. You can quote me here.
Sara Seager
MIT's planetary scientists specialize in polar planetary atmospheres.
Because they may never be able to confirm them, we have to get along with what we call “bio-signature planet candidates.” The planet needs more work to get there. You can be sure how others are working to produce DM without life.
I thank people for their enthusiasm. With more evidence, this and other planets may be “blessed” as biosignature candidates, but will remain in the candidate category indefinitely.
