An exoplanet called K2-18b is highlighting the complexities of finding life beyond Earth
A tiny sign revealed in April seemed like it might change the universe as we know it.
Astronomers had detected just a hint, a glimmer of two molecules swirling in the atmosphere of a distant planet called K2-18b — molecules that on Earth are produced only by living things. It was a tantalizing prospect: the most promising evidence yet of an extraterrestrial biosignature, or traces of life linked to biological activity.
But only weeks later, new findings suggest the search must continue.
'It was exciting, but it immediately raised several red flags because that claim of a potential biosignature would be historic, but also the significance or the strength of the statistical evidence seemed to be too high for the data,' said Dr. Luis Welbanks, a postdoctoral research scholar at Arizona State University's School of Earth and Space Exploration.
While the molecules identified on K2-18b by the April study — dimethyl sulfide, or DMS, and dimethyl disulfide, or DMDS — are associated largely with microbial organisms on our planet, scientists point out that the compounds can also form without the presence of life. Now, three teams of astronomers not involved with the research, including Welbanks, have assessed the models and data used in the original biosignature discovery and got very different results, which they have submitted for peer review.
Meanwhile, the lead author of the April study, Nikku Madhusudhan, and his colleagues have conducted additional research that they say reinforces their previous finding about the planet. And it's likely that additional observations and research from multiple groups of scientists are on the horizon.
The succession of research papers revolving around K2-18b offers a glimpse of the scientific process unfolding in real time. It's a window into the complexities and nuances of how researchers search for evidence of life beyond Earth — and shows why the burden of proof is so high and difficult to reach.
Located 124 light-years from Earth, K2-18b is generally considered a worthy target to scour for signs of life. It is thought to be a Hycean world, a planet entirely covered in liquid water with a hydrogen-rich atmosphere, according to previous research led by Madhusudhan, a professor of astrophysics and exoplanetary science at the University of Cambridge's Institute of Astronomy. And as such, K2-18b has rapidly attracted attention as a potentially habitable place beyond our solar system.
Convinced of K2-18b's promise, Madhusudhan and his Cambridge colleagues used observations of the planet by the largest space telescope in operation, the James Webb Space Telescope, to study the planet further. But two scientists at the University of Chicago — Dr. Rafael Luque, a postdoctoral scholar in the university's department of astronomy and astrophysics, and Michael Zhang, a 51 Pegasi b / Burbidge postdoctoral fellow — spotted some problems with what they found.
After reviewing Madhusudhan and his team's April paper, which followed up on their 2023 research, Luque and Zhang noticed that the Webb data looked 'noisy,' Luque said.
Noise, caused by imperfections in the telescope and the rate at which different particles of light reach the telescope, is just one challenge astronomers face when they study distant exoplanets. Noise can distort observations and introduce uncertainties into the data, Zhang said.
Trying to detect specific gases in distant exoplanet atmospheres introduces even more uncertainty. The most noticeable features from a gas like dimethyl sulfide stem from a bond of hydrogen and carbon molecules — a connection that can stretch and bend and absorb light at different wavelengths, making it hard to definitively detect one kind of molecule, Zhang said.
'The problem is basically every organic molecule has a carbon-hydrogen bond,' Zhang said. 'There's hundreds of millions of those molecules, and so these features are not unique. If you have perfect data, you can probably distinguish between different molecules. But if you don't have perfect data, a lot of molecules, especially organic molecules, look very similar, especially in the near-infrared.'
Delving further into the paper, Luque and Zhang also noticed that the perceived temperature of the planet appeared to increase sharply from a range of about 250 Kelvin to 300 Kelvin (-9.67 F to 80.33 F or -23.15 C to 26.85 C) in research Madhusudhan published in 2023 to 422 Kelvin (299.93 F or 148.85 C) in the April study.
Such harsh temperatures could change the way astronomers think about the planet's potential habitability, Zhang said, especially because cooler temperatures persist in the top of the atmosphere — the area that Webb can detect — and the surface or ocean below would likely have even higher temperatures.
'This is just an inference only from the atmosphere, but it would certainly affect how we think about the planet in general,' Luque said.
Part of the issue, he said, is that the April analysis didn't include data collected from all three Webb instruments Madhusudhan's team used over the past few years. So Luque, Zhang and their colleagues conducted a study combining all the available data to see whether they could achieve the same results, or even find a higher amount of dimethyl sulfide. They found 'insufficient evidence' of both molecules in the planet's atmosphere.
Instead, Luque and Zhang's team spotted other molecules, like ethane, that could fit the same profile. But ethane does not signify life.
Arizona State's Welbanks and his colleagues, including Dr. Matt Nixon, a postdoctoral researcher in the department of astronomy at the University of Maryland College Park, also found what they consider a fundamental problem with the April paper on K2-18b.
The concern, Welbanks said, was with how Madhusudhan and his team created models to show which molecules might be in the planet's atmosphere.
'Each (molecule) is tested one at a time against the same minimal baseline, meaning every single model has an artificial advantage: It is the only explanation permitted,' Welbanks said.
When Welbanks and his team conducted their own analysis, they expanded the model from Madhusudhan's study.
'(Madhusudhan and his colleagues) didn't allow for any other chemical species that could potentially be producing these small signals or observations,' Nixon said. 'So the main thing we wanted to do was assess whether other chemical species could provide an adequate fit to the data.'
When the model was expanded, the evidence for dimethyl sulfide or dimethyl disulfide 'just disappears,' Welbanks said.
Madhusudhan believes the studies that have come out after his April paper are 'very encouraging' and 'enabling a healthy discussion on the interpretation of our data on K2-18b.'
He reviewed Luque and Zhang's work and agreed that their findings don't show a 'strong detection for DMS or DMDS.' When Madhusudhan's team published the paper in April, he said the observations reached the three-sigma level of significance, or a 0.3% probability that the detections occurred by chance.
For a scientific discovery that is highly unlikely to have occurred by chance, the observations must meet a five-sigma threshold, or below a 0.00006% probability that the observations occurred by chance. Meeting such a threshold will require many steps, Welbanks said, including repeated detections of the same molecule using multiple telescopes and ruling out potential nonbiological sources.
While such evidence could be found in our lifetime, it is less likely to be a eureka moment and more a slow build requiring a consensus among astronomers, physicists, biologists and chemists.
'We have never reached that level of evidence in any of our studies,' Madhusudhan wrote in an email. 'We have only found evidence at or below 3-sigma in our two previous studies (Madhusudhan et al. 2023 and 2025). We refer to this as moderate evidence or hints but not a strong detection. I agree with (Luque and Zhang's) claim which is consistent with our study and we have discussed the need for stronger evidence extensively in our study and communications.'
In response to the research conducted by Welbanks' team, Madhusudhan and his Cambridge colleagues have authored another manuscript expanding the search on K2-18b to include 650 types of molecules. They have submitted the new analysis for peer review.
'This is the largest search for chemical signatures in an exoplanet to date, using all the available data for K2-18b and searching through 650 molecules,' Madhusudhan said. 'We find that DMS continues to be a promising candidate molecule in this planet, though more observations are required for a firm detection as we have noted in our previous studies.'
Welbanks and Nixon were pleased that Madhusudhan and his colleagues addressed the concerns raised but feel that the new paper effectively walks back central claims made in the original April study, Welbanks said.
'The new paper tacitly concedes that the DMS/DMDS detection was not robust, yet still relies on the same flawed statistical framework and a selective reading of its own results,' Welbanks said in an email. 'While the tone is more cautious (sometimes), the methodology continues to obscure the true level of uncertainty. The statistical significance claimed in earlier work was the product of arbitrary modeling decisions that are not acknowledged.'
Luque said the Cambridge team's new paper is a step in the right direction because it explores other possible chemical biosignatures.
'But I think it fell short in the scope,' Luque said. 'I think it restricted itself too much into being a rebuttal to the (Welbanks) paper.'
Separately, however, the astronomers studying K2-18b agree that pushing forward on researching the exoplanet contributes to the scientific process.
'I think it's just a good, healthy scientific discourse to talk about what is going on with this planet,' Welbanks said. 'Regardless of what any single author group says right now, we don't have a silver bullet. But that is exactly why this is exciting, because we know that we're the closest we have ever been (to finding a biosignature), and I think we may get it within our lifetime, but right now, we're not there. That is not a failure. We're testing bold ideas.'
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Gizmodo
42 minutes ago
- Gizmodo
Good News: Two of Apple TV+'s Most Slept-On Sci-Fi Shows Have Hopeful Plans for More
If you're a sci-fi fan, you really must check out Apple TV+—streaming home of so many of the best genre shows right now. Two standouts happen to have the same executive producer among their credits: David S. Goyer, who's part of team Murderbot as well as team Foundation. Murderbot's first season wraps up July 11, the same day Foundation returns for its third season. Neither show has been renewed beyond that, but to hear Goyer tell it, the future is looking bright. 'I don't want to give away too much, but I will say that moving from season season to season four is the first time we do not jump forward centuries,' Goyer said of Foundation. (The show's third season does indeed pick up 152 years after season two, as the season two finale had promised.) 'So in a way, one might think of season three and season four as one sort of 20-episode season.' That's exciting for fans of the Asimov adaptation to contemplate, as is his tease of season three, which builds out what fans have seen in the teaser and trailer so far: the story's big bad, the Mule (played by Game of Thrones' Pilou Asbæk), will play a major part this time around. 'I had always said, 'The Mule is season three. We have to earn the Mule,'' Goyer said. 'The reason why the Mule is so effective in the books is because it comes midway through the second novel, and you have to sort of set up the Foundation and set up the ways that its psychohistory seems to be kind of infallible and then the Mule is something that turns everything—the Mule doesn't work unless you've seen the Foundation succeed a number of times.' As for the future of Murderbot—which is based on Martha Wells' Murderbot Diaries book series—Goyer is similarly optimistic, echoing what series creators Chris and Paul Weitz told io9 ahead of the season premiere about its potential longevity, while pointing out the show has a surprisingly broad appeal. 'We've hit our Byzantine-metric threshold and I think it has performed well enough that there will be another season. It's not guaranteed, but I believe that to be the case,' Goyer said. 'And the response, critically, I think, could not have gone better. And what we're really interested in is, we knew we would get the sci-fi people in and the fans of the books, but we're just interested in sort of branching out beyond people that typically don't consider themselves fans of science fiction. Like my wife loves it, and she's not a science fiction fan. And so that's the audience that we're going for and we're hoping that that will continue.' Want more io9 news? Check out when to expect the latest Marvel, Star Wars, and Star Trek releases, what's next for the DC Universe on film and TV, and everything you need to know about the future of Doctor Who.
Fast Company
an hour ago
- Fast Company
This Perplexity cofounder wants to help AI breakthroughs graduate from university labs
A team of prominent AI researchers, led by Databricks and Perplexity cofounder Andy Konwinski, has launched Laude Institute, a new nonprofit that helps university-based researchers turn their breakthroughs into open-source projects, startups, or large-scale products with real-world impact. Laude brings together top academic and industry leaders to guide promising AI research out of the lab and into the world. Its mission: help more AI ideas cross the gap from paper to product. The effort builds on a growing belief within the AI and open-source communities that the field's biggest advances should be developed in public, not behind corporate walls. Many promising breakthroughs happen inside university labs, but often end up as research papers with no clear path to deployment. At the same time, as AI's development costs and potential rewards have skyrocketed, the need to support ambitious academic work outside of the big tech ecosystem has become more urgent. Konwinski, who was named one of Bloomberg 's ' New Billionaires of the AI Boom, ' has assembled a high-profile board for Laude. Among its members are Google's head of AI Jeff Dean, board chairman and Turing Award winner Dave Patterson, and Joëlle Pineau, a professor at McGill University and the Quebec AI Institute (Mila), and former Global VP of AI Research at Meta (FAIR). Laude's core goal is to replicate and enhance the university lab model used by departments like UC Berkeley's, known for foundational AI research. As a PhD student at Berkeley, Konwinski helped develop Apache Spark and later cofounded Databricks to commercialize it. That experience shaped his vision for Laude. 'I could do another company,' he says, 'but I'm honestly more interested in helping find other Databricks' and Perplexities and Linux and the internet and the personal computer.' Laude will focus on projects in four key areas: reinventing healthcare delivery (for example, by developing an AI-powered insulin pump), accelerating scientific breakthroughs (such as visualizing black holes or discovering new materials), revitalizing civic discourse (helping voters find common ground on controversial issues), and helping workers reskill for the AI age. These are domains where AI could have significant positive impact, but where the technology's potential is still largely untapped, Konwinski explains. Laude, a nonprofit with a public benefit corporation operating arm, will award grants to ambitious 'moonshot' projects that may take three to five years to complete. Selected projects will receive $250,000 seed grants, with the most promising progressing to multiyear research labs led by faculty affiliated with universities. 'Funding ambitious, high-impact work for long periods can give academic labs the autonomy to really identify and tackle significant societal challenges,' Dean says. 'This longer-term view can enable not just writing research papers but also creation of full-fledged working systems, open-source software to catalyze broader communities, or other forms of impact.' In addition, Laude will support 'slingshot' projects, providing fast, low-friction grants and embedded support for individual researchers aiming to launch startups or open-source projects. This could mean tens of thousands of dollars worth of compute time, funding for PhD or Postdoc support, or embedding engineers, designers, and communicators to help bring a product to completion. 'We talk about the right resource for the right researcher at the right time in order to maximize how many more open-source breakouts and how many more companies we can build,' says Konwinski, who has pledged $100 million of his own money to fund the first round of grants. Laude's primary value will not just be resources like talent and compute power, but guidance from people who have successfully brought technologies from lab to market. 'The academic model, when done well, can be excellent, but it doesn't necessarily have this ability to accelerate research at key points,' Pineau says. 'You need to bring in more resources, build artifacts that go beyond papers, and get them in front of users.' A network of advisers, including top professors and industry leaders, will help shape research projects by offering insights on product launches, multidisciplinary viewpoints, and best practices for open-source distribution. Among the advisers are Databricks CEO Ali Ghodsi, Jake Abernethy of Georgia Tech and Google DeepMind, Ludwig Schmidt of Stanford and Anthropic, Kurtis Heimerl of the University of Washington, Berkeley RISElab director Ion Stoica, and researcher-professors from Caltech, University of Wisconsin, and University of Illinois Urbana. For some researchers, Laude may provide an appealing alternative to venture capital. 'There are some projects where it's probably too risky for venture capitalists to take on,' Pineau says, while noting that not all VCs are the same. 'They tend to be a little bit shortsighted and want to see returns within a certain time frame, whereas a moonshot can tolerate higher risks.' There are also practical considerations. Some researchers prefer to keep one foot in academia, while VCs often want them to go full-time in the commercial space. Berkeley roots The inspiration for Laude dates back to Konwinski's days as a PhD student at Berkeley from 2007 to 2012. Patterson, then a professor in the computer science department, was instrumental in developing Berkeley's lab system. There, professors lead labs that attract PhD students and postdocs to pursue emerging fields like reinforcement learning. 'We developed this model of research labs with an opinionated style that were multidisciplinary,' Patterson says. Experts from across the university were brought in to offer fresh perspectives on the work. Labs were structured with five-year sunset clauses to encourage high-impact results. About a year ago, after founding Databricks and Perplexity, Konwinski returned to the department with the goal of using his new wealth to give more young researchers the experience he had. At Berkeley, PhD students sometimes write 'vision papers' on controversial topics. As a student, Konwinski wrote one on the value of cloud computing for research. Upon returning, he wanted to take on an even more ambitious subject: how to accelerate and improve the real-world impact of AI research. The result was ' Shaping AI,' a paper coauthored by Konwinski, Patterson, Pineau, and others, with input from Anthropic CEO Dario Amodei, Google DeepMind researcher and 2024 Nobel Prize winner John Jumper, Eric Schmidt, and former President Barack Obama. The idea for Laude took shape through writing the paper. 'We recognized that a way to help shape AI's impact was to set up prizes and research labs, similar to what we did at Berkeley,' Patterson says. 'The new idea was inducement prizes like the X-Prize, and also new labs in North America to tackle big problems and improve AI's outcomes for public good.' How Laude fits in Laude is not exactly an incubator or an accelerator. It represents something new, with a clear 'AI for good' mission and a conscientious approach to where and how the research is done. That starts with transparency. 'One of the requirements of this funding is to keep everything in the open,' Patterson says. 'There are not many requirements for grant recipients, but one is everything must be open source.' Konwinski is also focused on how researchers handle both the benefits and risks of the technology they create. Returning to Berkeley, he was troubled by the polarized tone of the AI debate. 'The AI discourse has ended up a bit polarized,' he says. 'It's the accelerationists and doomers. You either pump the brakes or you're pedal-to-the-metal. That loses nuance.' Konwinski believes in a rational middle ground. 'It would be just as much of a tragedy to ignore the upsides, especially medium and near-term upsides, as it would be to ignore the catastrophic potential.' Laude will encourage researchers to participate in public discussions about their work, partly to ensure they appreciate the weight of the decisions they are making. Too often, he says, executives like Sam Altman or Sundar Pichai lead the conversation about breakthrough technologies, not the Ilya Sutskevers and Jeff Deans who actually create them. Getting started On Thursday, June 19, Konwinski's voice was nearly gone after presiding over Laude's first Ship Your Research Summit the day before in San Francisco. The event brought together 70 handpicked researchers from more than two dozen universities for a day of salon-style discussions. Speakers included Jeff Dean and Dave Patterson, along with an off-record session with the Databricks founding team. Laude plans to make the summit an annual event to strengthen its community and attract new talent in computer science. Konwinski is particularly passionate when talking about Laude's community-building role. He wants Laude to serve as an anchor for researchers with strong academic ties who believe in open source and are motivated to use AI to tackle tough problems and seize new opportunities. 'It means you put people in a room and you make them like part of something bigger than themselves,' he says. 'It's like, 'Wow, I'm with my people here who want to move humanity forward by turning research into breakthroughs.' That's special.' Shortly after the summit, Laude announced its first major investment: $3 million a year for five years, comparable to a National Science Foundation grant, to fund a new AI-focused lab at UC Berkeley. The lab, led by a team of Berkeley's top researchers including Ion Stoica, Matei Zaharia, Joey Gonzalez, and Raluca Ada Papa, is set to open in 2027. The final deadline for Fast Company's Next Big Things in Tech Awards is Friday, June 20, at 11:59 p.m. PT. Apply today.
Associated Press
an hour ago
- Associated Press
Corramedical Opens Applications for 2025 Biopsy Catchment Biobank Investigators Award
'A biopsy represents an opportunity for diagnosis and discovery. This award encourages creative minds in biobanking to redefine what's possible with the cells we already extract — and usually discard.'— Wilfrido Mojica, MD LA JOLLA, CA, UNITED STATES, June 23, 2025 / / -- Corramedical, Inc., a leader in innovative biopsy specimen technologies, is now accepting applications for the 2025 Biopsy Catchment Biobank Investigators Award. This competitive grant program will award a total of $15,000 to support original research exploring the biobanking and biomarker potential of dislodged tumor cells recovered using the Crow's Nest™ Biopsy Catchment System. The Crow's Nest system is a portable, disposable tool designed to recover a second specimen — composed of viable, analyzable tumor cells — from material that is typically discarded during core needle biopsies. This minimally handled specimen, unexposed to formalin, represents a high-quality resource for biobanks and downstream 'omics research. Corramedical invites researchers to submit 500-word proposals demonstrating how this recovered cellular material can be incorporated into forward-thinking, integrated biobanking workflows. Proposals should highlight applications across genomics, transcriptomics, proteomics, or other emerging multiomic fields and articulate how these workflows could add value to both (a) biobank infrastructure and (b) biomarker discovery pipelines in academia and pharma. Key Award Details: • Award Amount: Three (3) recipients will receive $5,000 each. • Additional Support: Each award includes Crow's Nest devices, free of charge, in quantities specific to the winning protocol. • Eligibility: Open to U.S.-based applicants. Concurrent funding from other sources does not disqualify applicants. • Consultation: Applicants may request a complimentary project consultation with a Corramedical-affiliated pathologist or technical staff member. • Acknowledgment: Recipients are expected to cite the Crow's Nest Biopsy Catchment System in the methods section of resulting publications. Application Process: • Deadline: Applications will be reviewed on a rolling basis beginning July 1, 2025, and accepted throughout the remainder of the year. • Submission: Proposals (max 500 words) should be submitted via email to [email protected]. • Contact: For inquiries, contact +1-833-4-BIOPSY or visit 'Each core needle biopsy represents an opportunity not only for diagnosis but for discovery,' said Dr. Wilfrido Mojica, Corramedical Chief Technology Officer. 'This award encourages creative minds in biobanking to help redefine what's possible with the cells we already extract — and usually discard.' For updates, find Corramedical online at and follow us on LinkedIn at Corramedical is an EvoNexus portfolio company. Crow's Nest™, One Biopsy, Many Answers™, and Biopsy Catchment™ are trademarks of Corramedical, Inc. Nathan Edwards Corramedical, Inc. +1 833-424-6779 ext. 1 email us here Visit us on social media: LinkedIn Legal Disclaimer: EIN Presswire provides this news content 'as is' without warranty of any kind. We do not accept any responsibility or liability for the accuracy, content, images, videos, licenses, completeness, legality, or reliability of the information contained in this article. If you have any complaints or copyright issues related to this article, kindly contact the author above.
