Did scientists discover the life of another planet? Experts weigh the biological bomb report

Last week, researchers using James Web (JWST) have announced that they have found something intriguing on a distant exoplanet called the K2-18 B: potential breath of dimethyl sulfide, a molecule that is produced almost exclusively by microscopic marine life on Earth. The exoplanets, located about 120 light years, orbits in the habitable area of ​​the red dwarf star and can be a historian world: steam covered with an ocean planet with an atmosphere rich in hydrogen.

While the discovery comes with a statistical confidence of 3 sigma (very promising but not final), titles around the world are buzzing with speculation about the first discovery of life beyond Earth. But not everyone is convinced. Scientists from different disciplines are now weighed – some are cautiously optimistic about the latest research, while others are deeply skeptical. Can DMS be a sign of life or is it just strange, abiotic chemistry happens under extreme conditions?

For this last GIZ asks, we have rounded expert reactions to the discoveries, digging into chemistry, data restrictions and what will be needed to move the needle from “maybe” to something more categorical. Because in astrobiology, the line between Interested and exclusive is a thin razor. The following answers were slightly edited and condensed for clarity.

Oliver Short

A planetary chemist at the University of Cambridge, who studies the potential habitat of planets, among other things.

I have worked on the development of climate and structure understanding (ie the size and temperature of the atmosphere, what is at the heart of the atmosphere, etc.) of K2-18 B.

I do not believe that the DMS report on the K2-18 B spectrum moves the astrobiological needle. The series of steps to confidence we have seen signs of life beyond Earth are approximately:

1. Establish the signal really is the planet under consideration (in this case from the absorption of light passing through the atmosphere of the planet)
2. The signal is due to the biosigest of interest (in this case the molecular absorption in the DMS spectrum).
3. Exclude non -biological processes as the possibility of producing biosigointment.
4. Rule B (hypothetical) biological processes as an opportunity to produce a biosignor.

The discovery of the K2-18 B has not yet passed the 1st or 2nd as the community must confirm for itself that there is a signal. This is not my experience.

3 and 4 are close to my experience. Here the K2-18 B is a special challenge to life. There is currently no requirement from the data that this planet hosts oceans with liquid water and climate that can be lived. In fact, on the basis of the data, there are every reason to believe that the climate will be too hot for the oceans with liquid water, with the deep atmosphere potentially lined by the oceans of magma, not by liquid water. For this reason, even if 1 and 2 returned DMS detection, our expectation should be that this (molecule) appeared in a lifeless, hot, sulfur and hydrogen rich atmosphere and ask ourselves what the atmospheric chemistry that would allow. Believing instead that it is DMS of biological origin, it will require the cancellation of any expectation of the climate of this planet, for no other reason to do this from the data.

In other words, we are far from believing that the K2-18 B can be inhabited, let alone inhabited.

Christopher Glane

A geochimist at the Southwest Research Institute and an expert in the study of the possibility of extraterrestrial life in the ocean worlds.

This is a very interesting new set of data. There seems to be unexplained characteristics in the K2-18 B spectrum that can be attributed to dimethyl sulfide or dimethyl disulfide. However, these results are stretched JWST to its borders (K2-18 B is a very small planet) and it is possible to find further analysis a lack of statistically significant evidence of these characteristics. We need more astronomers in this case as soon as possible! I am currently intrigued, but cautious about the potential presence of these molecules of K2-18 B.

Even if DMS or DMD are present, we must be very careful to treat them as biosigantums. We just started asking questions about the abiotic origin of this type of planet. Exotic chemistry can surprise us, as the planets are more complicated (and wonderfully interesting) than we guess first. In order to open a life, many supportive evidence must be found and it will take time. Let’s learn these new results and get to work.

My In advance Includes an important finding cited below:

“Because a Revised Deep-on-Atmosphere Scenario Can Accommodate DEPLETED CO (Carbon Monoxide) and NH3 (Ammonia) Abundance, The Apparent Absnce of These Special Scenario for toi-270 D (A Planet Orbiting Another Red Dwarf, Discovered in 2019) and Similar Planes, Such As K2-18 B. excludes the existence of predatory worlds.

Niku Madhusudhan

Astrophysicist at the University of Cambridge and a leading author of a recent study.

The needle is a little more in the direction of the potential life than before, but we have to remain very cautious and open to other options.

I think what we need to get excited about is the fact that we have some data to start even discussing the possibilities. I think more data

In the next 1 to 2 years, they must provide better restrictions.

Igas Snelan

An astrophysicist at the University of Leiden and an expert on extraslar planets.

The whole thing is completely blown away by the proportions. I’m sorry to be a little short in my answers, but in the last two days I had to deal with it in the Dutch and Belgian media and I’m a little done.

The research team finds bumps in its spectrum. It is unclear if they are real and if so, what they could be caused by. There may be dozens of molecules (if real) or even cloud characteristics. What do the authors do? They just watch if DMS can cause this (and add DMD). They ignore dozens of other species (ie non -biological sources of molecules) that could cause this stroke and call it a day. If I were a referee, I would have stopped this post right there. There is no reason to refer to astrobiology, let alone call it the largest breakthrough or anything.

Most reporters write a piece where they say something like “However, not all scientists are as convinced …” I can tell you that it is much worse than that, but most of us keep their mouths closed. I understand why in these difficult times, but in the long run it will hurt astronomy when no one will take us seriously. You can quote me about it.

Sarah Siger

A planetary scientist from MIT specializing in the atmosphere of an extraosolar planet.

Since they may never be confirmed in any way, we must live with what we might call “bio -bio -bio -planet candidates.” This planet needs more work to get there. You can be sure that others work in ways in which DM can be produced without life.

I appreciate people’s enthusiasm. With more evidence, this and other planets can be “blessed” as bio -native candidates, but will remain in the candidate category for an indefinite period of time.