Latest news with #StephenSchmidt
Yahoo
09-05-2025
- Science
- Yahoo
Why Astronomers Doubt Claims That Planet K2-18 b Finding Means Alien Life
A University of Cambridge-led team of astronomers made worldwide headlines last night with claims that they had found the 'strongest hints yet of biological activity outside the Solar System'. The discovery involves a distant planet known as K2-18 b, which the team says has one or more molecules in its atmosphere that might have been generated by living things. The announcement has been met with floods of scepticism from other researchers who study such 'biosignatures' in exoplanet atmospheres. 'It is not strong evidence,' says Stephen Schmidt, an astronomer at Johns Hopkins University in Baltimore, Maryland. 'It's almost certainly not life,' says Tessa Fisher, an astrobiologist at the University of Arizona in Tucson. [Sign up for Today in Science, a free daily newsletter] Here, Nature explores the high-profile claim — and why many scientists say it's far from proof of alien life. Using the James Webb Space Telescope (JWST), the Cambridge team reported finding hints of the molecule dimethyl sulfide (DMS), a pungent smelling compound that can be produced by bacteria, in the atmosphere of K2-18 b, a planet smaller than Neptune that lies about 38 parsecs from Earth. The scientists detected the molecule by analysing starlight as it filtered through the planet's atmosphere; different chemical compounds leave identifying imprints in the light's spectrum. The data might indicate the presence of the related molecule dimethyl disulfide (DMDS), either in addition to DMS or in its stead. These chemicals are intriguing because on Earth they are produced by living organisms such as marine phytoplankton. In 2023, the researchers reported similar findings. This follow-up work looks at the planet in a different set of wavelengths and is a stronger and cleaner signal that the molecules are present, the team says. Being able to tease out the detailed chemistry of a faraway planet is a technical tour-de-force, the researchers say. 'What we are seeing is a major paradigm shift in the field of exoplanet science,' said team leader Nikku Madhusudhan, an astronomer at Cambridge, in a livestreamed colloquium on 17 April. He did not respond to a request for an interview before press time for this story. Scientists have been looking for life beyond Earth for centuries. If DMS and DMDS do exist in this planet's atmosphere, and if they are formed by biological activity, it would represent a groundbreaking moment in the search for extraterrestrial life. The work also marks a step toward understanding planets like K2-18 b, which are some of the most common of the 5,800-plus planets that have so far been identified throughout the universe. They are referred to as 'mini Neptunes' based on their mass, but beyond that, little is known about their makeup. Some researchers, including Madhusudhan's team, say that some could be exotic water worlds cloaked in hydrogen atmospheres. If so, they may be some of the best places to look for the existence of extraterrestrial life. For starters, there are questions about whether K2-18 b even has water — or a surface where anything could live. Modelling studies of it and similar planets suggest that they are probably barren. 'A lifeless mini-Neptune scenario remains the most parsimonious explanation,' says Joshua Krissansen-Totton, a planetary scientist at the University of Washington in Seattle. Then there's the issue of whether DMS/DMDS is actually present, or whether it is a spurious signal. The measurement reported by the Cambridge team is 'really pushing the limit of what JWST can do,' says Laura Kreidberg, an astronomer at the Max Planck Institute for Astronomy in Heidelberg, Germany. Schmidt and his colleagues recently re-analysed the 2023 claim from the Cambridge team and found no evidence of biosignature molecules in that data. Schmidt says the new observations are 'pretty noisy, and any reported features could still just be statistical fluctuations'. For their part, the Cambridge researchers say there is just a 0.3% probability that the signal could be due to chance. Finally, if the DMS/DMDS signal is indeed real, then there are many additional questions that need to be resolved before it could be attributed to life, other researchers say. For instance, laboratory experiments have shown that DMS can be made through abiotic processes — those not involving life. 'We know very little about the chemistry of these atmospheres,' says Eleanor Browne, a chemist at the University of Colorado Boulder who led that recent study. Others have reported that DMS is present on a comet explored by the European Space Agency, which definitely does not have life on it. 'The planetary context is what matters,' says Edward Schweiterman, an astrobiologist at the University of California Riverside. If the molecules really are in the planet's atmosphere, he says, 'we have to brainstorm novel ways of producing a lot of it through abiotic means and evaluate those possibilities before accepting it as evidence for life.' Madhusudhan and his colleagues hope to get more observing time with JWST to help nail down the statistical significance of their claim. Beyond that, says Schweiterman, 'what you'd like to see is validation from multiple independent groups.' Regardless of how the claim plays out, it highlights the importance of studying planets like K2-18 b, Kreidberg says: 'This is a very, very rich playground for us to understand how planetary atmospheres work.' This article is reproduced with permission and was first published on April 17, 2025.
CBS News
01-05-2025
- Politics
- CBS News
Baltimore-area organizations protest Trump administration's policy changes during May Day
Several Baltimore-area organizations rallied Thursday for May Day, protesting recent policy changes by the Trump administration. May Day, which is also known as International Workers' Day, is observed annually. This year, some workers are taking the opportunity to voice opposition to changes by the federal government that, they say, have attacked healthcare, jobs, immigrant rights and student protections. Several Baltimore-area organizations rallied Thursday for May Day. CBS News Baltimore Protestors rally at Johns Hopkins University Teachers and Researchers United (TRU-UE) Local 197, a PhD workers' union at Johns Hopkins University, joined the rallies on May Day to demand that the university's administration protect international students, workers and research funding. "The upshot is that we want them to be proactive about protecting our workers' rights, to protect them from ICE and to protect their research funding," said Stephen Schmidt, a graduate worker and member of TRU-UE Local 197. "It is very important for people on campus to be able to do their research and teaching work without fear of ICE or their funding being cut or anything like that," Schmidt added. Graduate workers on the picket line called on Johns Hopkins University to back up their support of academic freedom with actions opposing the Trump administration. The union is calling for the university to agree to their five demands: Declare Johns Hopkins University (JHU) a sanctuary campus End surveillance on the student body, delete the data of students and workers and end the Johns Hopkins Police Department and campus militarization Support the non-U.S. citizens on campus Commit to fully funding all ongoing research and training projects Publicly affirm the university's support for academic freedom, rigorous scientific inquiry and its commitment to evidence-based research and clinical practice. "We're going to keep making noise until our academic freedom and our international workers have adequate protection," said Sheridon Ward, a graduate worker with TRU-UE Local 197. "We have a responsibility to use our union power when our workers are threatened." Johns Hopkins University responds to May Day protestors WJZ reached out to Johns Hopkins University regarding the student concerns, and a university spokesperson wrote: "Johns Hopkins University deeply values our international students and staff, and we remain committed to maintaining healthcare, learning, and working environments that allow for the discussion and dialogue essential to academic and community life. We have regularly communicated with our community about the range of support services we provide for our international affiliates, as well as our longstanding policy of not providing information about a JHU affiliate's immigration status unless required by law and not allowing immigration authorities access to private JHU facilities absent a court order." The spokesperson further explained that JHU was home to the early development of the concept of academic freedom in the U.S., and it remains a foundational value at the heart of their mission. "We are committed to the steadfast protection of free expression, as long as individuals and groups comply with our rules, policies, and guidelines. Our guidelines include a prohibition on the disruption of Johns Hopkins operations, and we have been clear that acts of hate, threats, and discrimination violate university policy and the student code of conduct," the statement continued. On Monday, the university announced several new support programs for members of the JHU research community who are facing unexpected grant terminations, delays or other interruptions. In response to immigration concerns, JHU also published a detailed Q&A on its public safety website. What prompted May Day rallies? Recent changes by the Trump administration have angered many residents in Baltimore and the greater Maryland area. Several Baltimore-area organizations rallied Thursday for May Day. CBS News Baltimore Last month, protestors gathered outside Baltimore City Hall as part of the "Hands Off!" movement, which protested recent efforts to reduce the size of the federal workforce. Those efforts have included staffing cuts at the Department of Veterans Affairs, the National Oceanic and Atmospheric Administration and the Social Security Administration. Maryland is home to about 160,000 federal civilian employees, which represents 6% of all state jobs, according to Gov. Wes Moore's office. Groups also protested against federal immigration policies, the dissolution of diversity policies and in favor of LGBTQ+ rights during May Day on Thursday. One of the rallies was also for the March for Palestinian-controlled territories – a joint effort by several groups in Baltimore. Another gathering, the "99 vs 1 March," was carried out by a group hoping to remind people about the power of democracy.
Boston Globe
17-04-2025
- Science
- Boston Globe
Astronomers detect a possible signature of life on a distant planet
'This is a revolutionary moment,' Madhusudhan said. 'It's the first time humanity has seen potential biosignatures on a habitable planet.' Advertisement The study was published Wednesday in the Astrophysical Journal. Other researchers called it an exciting, thought-provoking first step to making sense of what's on K2-18b. But they were reluctant to draw grand conclusions. 'It's not nothing,' said Stephen Schmidt, a planetary scientist at Johns Hopkins University. 'It's a hint. But we cannot conclude it's habitable yet.' If there is extraterrestrial life on K2-18b, or anywhere else, its discovery will arrive at a frustratingly slow pace. 'Unless we see E.T. waving at us, it's not going to be a smoking gun,' said Christopher Glein, a planetary scientist at the Southwest Research Institute in San Antonio. Advertisement Joshua Krissansen-Totton, an astrobiologist at the University of Washington, said he worried that American astrobiologists may not be able to follow up on the latest results on K2-b18b. The Trump administration is reportedly planning to cut NASA's science budget in half, eliminating future space telescope and other astrobiology projects. If that happens, Krissansen-Totton said, 'the search for life elsewhere would basically stop.'
