In 2023, scientists from the University of Cambridge reported what appeared to be very exciting news. They said that NASA’s James Web telescope had discovered signs of liquid water perimeter-and for life-on K2-18B abroad, a mild world without concrete located about 124 light-years from Earth. Then, earlier this year, the same team announced what they called stronger evidence of these possible signs of strange life.
The signs were rooted in a preliminary discovery of the DMS – a molecule that is produced on the ground only from marine life – and/or nearby chemical DMDS, which is also vital potential, in the sulfur atmosphere. This discovery, along with the possibility of K2-18B “Hycean” with liquid water perimeter, has caused great attention to its ability to support life.
However, these results sparked an intense debate among astronomers. While the realization of this conclusion will be a pioneering achievement and a great testimony on the capabilities of the JMST Telescope (JWST) if it is true, many scientists are still skeptical, as they question the reliability of the discovered DMS signature as well as whether the DMS itself is a sign of life in the first place. As such, many independent teams conduct follow-up studies on original claims-adding only the newly published teams adding, indicating that the discovery of the DMS for Cambridge scientists was not important enough to justify the advertising they received.
“Among the physical sciences, she has a distinguished position,” said Rafael Locke, a doctoral researcher at the University of Chicago. “It is frequently covered in the media thanks to its visual attractiveness and the great philosophical and global questions you are eating. So it was expected that – even if it was initial – the discovery of a potential vital sign in the atmosphere of external planets will have wide coverage.”
The importance of importance
Locke and his colleagues, including after the post-PhD, Caroline Piolite Gorib and Michael Chang, are still not convinced that what astronomers noticed on K2-18B had actually a reliable signature indicating life. In a modern arxiv Preprint -who was not reviewed by the peers-their team re-examined the authenticity of the original evidence. “This is the way science works: the evidence and confrontation confrontation are side by side.”
When scientists study data from different tools separately, they may end up with conflicting results – it is similar to finding two different “stories” on a topic that does not match. “This is, in fact, what happened in the papers of the original team,” Zhang told Space.com. “Because of the Mary (mid -red radiation) data from their data from Niriss and Niriss (near infrared). The installation of all data with the same model ensures that we do not tell stories contradictory about the same planet.”
Thus, the team conducted a joint analysis of the K2-18B using data from all the three main tools of JWST- Infrared and NIRIS infrared infrared and infrared spectrum devices, which capture the surface near infrared, and the mid-infrared tool, which detects long circumambulations in the middle. The goal was to guarantee a fixed explanation at the cute planet K2-18b that the team felt the original studies that it lacks.
“We re -analyzed the same JWST data used in the published study earlier this year, but in conjunction with other JWST notes from the same planet published […] Two years ago, Piolite Gorib told Space.com.
These signs may appear weaker when all data is combined because the initial “strong” detection may be exaggerated, as the team says, due to a limited initial data set. The combination of data from multiple sources allows scientists to examine and verify strength-reform-for a certain indication.
“The ways to reduce different data and retrieval symbols always give a little different results, so it is important to try multiple ways to see the strength of the results,” explained by Piolite Gorib. “We haven’t seen more than small hints either DMS or DMDS, and even these hints were not present in all data discounts.”
“More importantly, we have shown that when testing a wide range of molecules that we expect to be produced indirectly in the atmosphere, the same spectral features are observed without the need for DMS or DMDS,” I continued.
More than one path to the result
The molecules are usually discovered in the atmosphere of the outer planets through spectral analysis, which determine the unique “chemical fingerprints” based on how the planet’s atmosphere absorbed to specific wavelengths of the light of stars while it is – or transient – in front of the host star. This absorption leaves distinctive patterns in the light spectrum that reveals the presence of different particles.
“The signature of each unique molecule, but different molecules can contain some features that fall into similar places due to their nearby molecular structures,” explained by Piolite Gorib.
The difference between DMS and ethane – a common molecule in the atmosphere of external planets – is just one atom of sulfur, and the current spectrum, including those in JWST, has an impressive sensitivity, but it is still limits. The distance to the external planets, fainting signals, and the complexity of the atmosphere distinguish between the particles that differ only one seed is very difficult.
“It is widely recognized as a major problem to detect vital signs, although it is not a problem that cannot be overcome, because different molecules have different different absorption features.” “In order to be able to separate these signals more clearly, we must be particularly keen not to misuse them as signs of life.”
Besides technical restrictions, another source of doubt is how the data has been interpreted statistically. Luque notes that the 2023 study described the DMS discovery as “temporary”, which reflects the primary nature of the discovery. However, the last leaf 2025 mentioned that the discovery of DMS and/or DMDS reached the importance of 3-Sigma-which is a level, although it is less than the 5-Sigma threshold required for a certain discovery, which is generally considered a moderate statistical guide.
Surprisingly, This is the last work He was Used to double the bottom to claim DMS Even more complex molecules to be present. However, the disclosure is not a statistical or strong significance, as we appear in our work.
Despite this uncertainty, the team is concerned that media coverage continued to highlight bold demands about DMS and other particles. “the [JWST] The telescope is incredibly strong, but the signals we discover are very small. As a society, we must make sure that any claims we make about the formation of the planet are strong for the options taken when processing data from the telescope, “said Piolite Gorib.
Locke added: “The researchers bear the responsibility for double verification and verification, but the media is also responsible for reporting these follow -up work to the general public,” Locke added. “Even if they have less attractive titles.”
Locke said: “As Karl Sagan once said, extraordinary claims require extraordinary evidence,” Locke said. “This threshold was not fulfilled by publishing the results for the general public.”
whether We will get a clear answer to life on the K2-18 B is not sure-not only because of the technological boundaries, but because the state of follow-up with JWST may not be strong enough. “JWST continues to monitor K2-18B, and although new notes will not have the ability to discover life, we will soon discover more about the planet and the interior’s atmosphere,” said Zhang.
