Latest news with #alienlife
Yahoo
25-05-2025
- Science
- Yahoo
Doubts over hope of alien life on exoplanet K2-18b as case for biosignatures weakens
A growing number of studies have cast doubt on earlier claims about signs of life on K2-18b, a planet 124 light-years away in the Leo constellation, concluding that the available data doesn't support such bold interpretations. Last month, scientists had announced that they might have identified what appeared to be the most promising signs of alien life discerned so far on the distant planet. However, latest research contends that there was not enough evidence to estimate alien presence. K2-18b orbits within the habitable zone of its star, making it a compelling target for the search of alien life due to the potential presence of liquid water. Astronomers working with the James Webb Space Telescope drew global attention in April by reporting possible traces of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) in the planet's atmosphere. On Earth, these compounds are produced exclusively by living organisms such as marine algae, which is why they are considered potential biosignatures—chemical hints that life might exist elsewhere. Led by Cambridge University's Nikku Madhusudhan, the research team was careful to stress that the potential biosignature was far from conclusive. The signal reached a three-sigma level of statistical significance, meaning there remains a small but meaningful possibility that the result was a fluke. Two of Madhusudhan's former students, Luis Welbanks of Arizona State University and Matthew Nixon of the University of Maryland, were part of a team that re-examined the data behind the initial announcement. In a preprint study published online towards the end of last month, they reported that when using alternative statistical models, the signals originally interpreted as potential biosignatures no longer stand out. In one approach, the researchers broadened the pool of possible atmospheric chemicals from 20 to 90, significantly weakening the case for a unique biological explanation. Embracing the ongoing scientific discussion, Madhusudhan highlighted the importance of keeping an open mind throughout the research process. His team added to the conversation by releasing a new preprint study last week that expanded the list of potential atmospheric chemicals to 650. Among the top candidates identified as an indicator of alien life was dimethyl sulfide (DMS). Meanwhile, dimethyl disulfide (DMDS), which had featured prominently in their earlier announcement, was no longer considered a leading possibility. Astronomers observe distant exoplanets like K2-18b by tracking their passage across their host stars, which allows them to analyze how molecules in the planet's atmosphere absorb specific wavelengths of starlight. Earlier this week, a study led by postdoctoral researcher Rafael Luque at the University of Chicago combined Webb's observations of K2-18b in both near-infrared and mid-infrared wavelengths. The research found no statistically significant evidence for dimethyl sulfide (DMS) or dimethyl disulfide (DMDS). In addition, an earlier paper by Oxford astrophysicist Jake Taylor, using a basic statistical method, also reported no strong signs of biosignatures. However, Madhusudhan dismissed Taylor's paper noting the simple exercise used to draw conclusions was far from a robust method to observe physical phenomena. The scientist also highlighted that more data on K2-18b will be collected over the next year, which should help provide a clearer and more definitive picture.
Malay Mail
24-05-2025
- Science
- Malay Mail
Space spat: Webb hints at life — but not everyone's buying it
PARIS, May 25 — When astronomers announced last month they might have discovered the most promising hints of alien life yet on a distant planet, the rare good news raised hopes humanity could soon learn we are not alone in the universe. But several recent studies looking into the same data have found that there is not enough evidence to support such lofty claims, with one scientist accusing the astronomers of 'jumping the gun'. The debate revolves around the planet K2-18b, which is 124 light years away in the Leo constellation. The planet is thought to be the right distance from its star to have liquid water, making it a prime suspect in the search for extraterrestrial life. Last month, astronomers using the James Webb Space Telescope made headlines by announcing they had detected hints of the chemicals dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) on the planet. These chemicals are only produced by life such as marine algae on Earth, meaning they are considered potential 'biosignatures' indicating life. The astronomers, led by Cambridge University's Nikku Madhusudhan, expressed caution about the 'hints' of a biosignature, emphasising they were not claiming a definitive discovery. Their detection had reached a three-sigma level of statistical significance 'which means there is still a three in 1,000 chance of this being a fluke,' Madhusudhan said at the time. Biosignatures 'vanish' Two of Madhusudhan's former students, Luis Welbanks of Arizona State University and Matthew Nixon of Maryland University, were among the researchers who have since re-analysed the data behind the announcement. When deploying other statistical models, 'claims of a potential biosignature detection vanish', according to their preprint study published online late last month. Like the other papers since the April announcement, it has not been peer-reviewed. In one model, Welbanks and colleagues expanded the number of possible chemicals that could explain the signals detected by Webb to 90 from the original 20. More than 50 received a 'hit', Welbanks told AFP. 'When you detect everything, did you really detect anything?' he asked. They are not saying the planet definitely does not have DMS — just that more observations are needed, Welbanks added. 'Arguments are healthy' Madhusudhan welcomed the robust debate, saying that remaining open to all possibilities is an essential part of the scientific method. 'These sorts of arguments are healthy,' he told AFP. His team even went further, releasing their own preprint study last week that expanded the number of chemicals even further to 650. The three most 'promising' chemicals they found included DMS but not DMDS — a major part of the team's announcement in April. The other two chemicals were diethyl sulfide and methyl acrylonitrile, the latter of which is toxic. Madhusudhan admitted that these little-known chemicals are likely not 'realistic molecules' for a planet like K2-18b. Welbanks pointed out that 'in the span of a month — with no new data, with no new models, with no new laboratory data — their entire analysis changed'. 'Closest we have ever been' Telescopes observe such far-off exoplanets when they cross in front of their star, allowing astronomers to analyse how molecules block different wavelengths of light streaming through their atmosphere. Earlier this week, a paper led by Rafael Luque at the University of Chicago combined Webb's observations of K2-18b in both the near-infrared and mid-infrared wavelengths of light. It also found 'no statistical significance for DMS or DMDS', the paper said. An earlier paper by Oxford astrophysicist Jake Taylor using a basic statistical test also found no strong evidence for any biosignatures. Madhusudhan dismissed the latter paper, saying the simple exercise did not account for observing physical phenomena. He also stood by his research, saying he was 'just as confident' in the work as he was a month ago. More data about K2-18b will come in over the next year which should offer a much clearer picture, Madhusudhan added. Even if the planet does have DMS, it is not a guarantee of life — the chemical has been detected on a lifeless asteroid. However, many researchers do believe that space telescopes could one day collect enough evidence to identify alien life from afar. 'We are the closest we have ever been' to such a moment, Welbanks said. 'But we have to use the frameworks that are in place and build up (evidence) in a reliable method, rather than using non-standard practices and jumping the gun — as has been done in this particular case,' Nixon added. — AFP
Asharq Al-Awsat
24-05-2025
- Science
- Asharq Al-Awsat
Doubt Cast on Claim of ‘Hints' of Life on Faraway Planet
When astronomers announced last month they might have discovered the most promising hints of alien life yet on a distant planet, the rare good news raised hopes humanity could soon learn we are not alone in the universe. But several recent studies looking into the same data have found that there is not enough evidence to support such lofty claims, with one scientist accusing the astronomers of "jumping the gun". The debate revolves around the planet K2-18b, which is 124 light years away in the Leo constellation. The planet is thought to be the right distance from its star to have liquid water, making it a prime suspect in the search for extraterrestrial life. Last month, astronomers using the James Webb Space Telescope made headlines by announcing they had detected hints of the chemicals dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) on the planet. These chemicals are only produced by life such as marine algae on Earth, meaning they are considered potential "biosignatures" indicating life. The astronomers, led by Cambridge University's Nikku Madhusudhan, expressed caution about the "hints" of a biosignature, emphasizing they were not claiming a definitive discovery. Their detection had reached a three-sigma level of statistical significance "which means there is still a three in 1,000 chance of this being a fluke," Madhusudhan said at the time. Two of Madhusudhan's former students, Luis Welbanks of Arizona State University and Matthew Nixon of Maryland University, were among the researchers who have since re-analyzed the data behind the announcement. When deploying other statistical models, "claims of a potential biosignature detection vanish", according to their preprint study published online late last month. Like the other papers since the April announcement, it has not been peer-reviewed. In one model, Welbanks and colleagues expanded the number of possible chemicals that could explain the signals detected by Webb to 90 from the original 20. More than 50 received a "hit", Welbanks told AFP. "When you detect everything, did you really detect anything?" he asked. They are not saying the planet definitely does not have DMS -- just that more observations are needed, Welbanks added. Madhusudhan welcomed the robust debate, saying that remaining open to all possibilities is an essential part of the scientific method. "These sort of arguments are healthy," he told AFP. His team even went further, releasing their own preprint study last week that expanded the number of chemicals even further to 650. The three most "promising" chemicals they found included DMS but not DMDS -- a major part of the team's announcement in April. The other two chemicals were diethyl sulfide and methyl acrylonitrile, the latter of which is toxic. Madhusudhan admitted that these little-known chemicals are likely not "realistic molecules" for a planet like K2-18b. Welbanks pointed out that "in the span of a month -- with no new data, with no new models, with no new laboratory data -- their entire analysis changed". Telescopes observe such far-off exoplanets when they cross in front of their star, allowing astronomers to analyze how molecules block different wavelengths of light streaming through their atmosphere. Earlier this week, a paper led by Rafael Luque at the University of Chicago combined Webb's observations of K2-18b in both the near-infrared and mid-infrared wavelengths of light. It also found "no statistical significance for DMS or DMDS", the paper said. An earlier paper by Oxford astrophysicist Jake Taylor using a basic statistical test also found no strong evidence for any biosignatures. Madhusudhan dismissed the latter paper, saying the simple exercise did not account for observing physical phenomena. He also stood by his research, saying he was "just as confident" in the work as he was a month ago. More data about K2-18b will come in over the next year which should offer a much clearer picture, Madhusudhan added. Even if the planet does have DMS, it is not a guarantee of life -- the chemical has been detected on a lifeless asteroid. However, many researchers do believe that space telescopes could one day collect enough evidence to identify alien life from afar. "We are the closest we have ever been" to such a moment, Welbanks said. "But we have to use the frameworks that are in place and build up (evidence) in a reliable method, rather than using non-standard practices and jumping the gun -- as has been done in this particular case," Nixon added.
Japan Times
24-05-2025
- Science
- Japan Times
Doubt cast on claim of 'hints' of life on faraway planet
When astronomers announced last month they might have discovered the most promising hints of alien life yet on a distant planet, the rare good news raised hopes humanity could soon learn we are not alone in the universe. But several recent studies looking into the same data have found that there is not enough evidence to support such lofty claims, with one scientist accusing the astronomers of "jumping the gun." The debate revolves around the planet K2-18b, which is 124 light years away in the Leo constellation. The planet is thought to be the right distance from its star to have liquid water, making it a prime suspect in the search for extraterrestrial life. Last month, astronomers using the James Webb Space Telescope made headlines by announcing they had detected hints of the chemicals dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) on the planet. These chemicals are only produced by life such as marine algae on Earth, meaning they are considered potential "biosignatures" indicating life. The astronomers, led by Cambridge University's Nikku Madhusudhan, expressed caution about the "hints" of a biosignature, emphasizing they were not claiming a definitive discovery. Their detection had reached a three-sigma level of statistical significance "which means there is still a three in 1,000 chance of this being a fluke," Madhusudhan said at the time. Two of Madhusudhan's former students, Luis Welbanks of Arizona State University and Matthew Nixon of Maryland University, were among the researchers who have since re-analyzed the data behind the announcement. When deploying other statistical models, "claims of a potential biosignature detection vanish," according to their preprint study published online late last month. Like the other papers since the April announcement, it has not been peer-reviewed. In one model, Welbanks and colleagues expanded the number of possible chemicals that could explain the signals detected by Webb to 90 from the original 20. More than 50 received a "hit," Welbanks said. "When you detect everything, did you really detect anything?" he asked. They are not saying the planet definitely does not have DMS — just that more observations are needed, Welbanks added. Madhusudhan welcomed the robust debate, saying that remaining open to all possibilities is an essential part of the scientific method. "These sort of arguments are healthy," he said. His team even went further, releasing their own preprint study last week that expanded the number of chemicals even further to 650. The three most "promising" chemicals they found included DMS but not DMDS — a major part of the team's announcement in April. The other two chemicals were diethyl sulfide and methyl acrylonitrile, the latter of which is toxic. Madhusudhan admitted that these little-known chemicals are likely not "realistic molecules" for a planet like K2-18b. Welbanks pointed out that "in the span of a month — with no new data, with no new models, with no new laboratory data — their entire analysis changed." Telescopes observe such far-off exoplanets when they cross in front of their star, allowing astronomers to analyze how molecules block different wavelengths of light streaming through their atmosphere. Earlier this week, a paper led by Rafael Luque at the University of Chicago combined Webb's observations of K2-18b in both the near-infrared and mid-infrared wavelengths of light. It also found "no statistical significance for DMS or DMDS," the paper said. An earlier paper by Oxford astrophysicist Jake Taylor using a basic statistical test also found no strong evidence for any biosignatures. Madhusudhan dismissed the latter paper, saying the simple exercise did not account for observing physical phenomena. He also stood by his research, saying he was "just as confident" in the work as he was a month ago. More data about K2-18b will come in over the next year which should offer a much clearer picture, Madhusudhan added. Even if the planet does have DMS, it is not a guarantee of life — the chemical has been detected on a lifeless asteroid. However, many researchers do believe that space telescopes could one day collect enough evidence to identify alien life from afar. "We are the closest we have ever been" to such a moment, Welbanks said. "But we have to use the frameworks that are in place and build up (evidence) in a reliable method, rather than using non-standard practices and jumping the gun — as has been done in this particular case," Nixon added.
Yahoo
24-05-2025
- Science
- Yahoo
Doubt cast on claim of 'hints' of life on faraway planet
When astronomers announced last month they might have discovered the most promising hints of alien life yet on a distant planet, the rare good news raised hopes humanity could soon learn we are not alone in the universe. But several recent studies looking into the same data have found that there is not enough evidence to support such lofty claims, with one scientist accusing the astronomers of "jumping the gun". The debate revolves around the planet K2-18b, which is 124 light years away in the Leo constellation. The planet is thought to be the right distance from its star to have liquid water, making it a prime suspect in the search for extraterrestrial life. Last month, astronomers using the James Webb Space Telescope made headlines by announcing they had detected hints of the chemicals dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) on the planet. These chemicals are only produced by life such as marine algae on Earth, meaning they are considered potential "biosignatures" indicating life. The astronomers, led by Cambridge University's Nikku Madhusudhan, expressed caution about the "hints" of a biosignature, emphasising they were not claiming a definitive discovery. Their detection had reached a three-sigma level of statistical significance "which means there is still a three in 1,000 chance of this being a fluke," Madhusudhan said at the time. - Biosignatures 'vanish' - Two of Madhusudhan's former students, Luis Welbanks of Arizona State University and Matthew Nixon of Maryland University, were among the researchers who have since re-analysed the data behind the announcement. When deploying other statistical models, "claims of a potential biosignature detection vanish", according to their preprint study published online late last month. Like the other papers since the April announcement, it has not been peer-reviewed. In one model, Welbanks and colleagues expanded the number of possible chemicals that could explain the signals detected by Webb to 90 from the original 20. More than 50 received a "hit", Welbanks told AFP. "When you detect everything, did you really detect anything?" he asked. They are not saying the planet definitely does not have DMS -- just that more observations are needed, Welbanks added. - 'Arguments are healthy' - Madhusudhan welcomed the robust debate, saying that remaining open to all possibilities is an essential part of the scientific method. "These sort of arguments are healthy," he told AFP. His team even went further, releasing their own preprint study last week that expanded the number of chemicals even further to 650. The three most "promising" chemicals they found included DMS but not DMDS -- a major part of the team's announcement in April. The other two chemicals were diethyl sulfide and methyl acrylonitrile, the latter of which is toxic. Madhusudhan admitted that these little-known chemicals are likely not "realistic molecules" for a planet like K2-18b. Welbanks pointed out that "in the span of a month -- with no new data, with no new models, with no new laboratory data -- their entire analysis changed". - 'Closest we have ever been' - Telescopes observe such far-off exoplanets when they cross in front of their star, allowing astronomers to analyse how molecules block different wavelengths of light streaming through their atmosphere. Earlier this week, a paper led by Rafael Luque at the University of Chicago combined Webb's observations of K2-18b in both the near-infrared and mid-infrared wavelengths of light. It also found "no statistical significance for DMS or DMDS", the paper said. An earlier paper by Oxford astrophysicist Jake Taylor using a basic statistical test also found no strong evidence for any biosignatures. Madhusudhan dismissed the latter paper, saying the simple exercise did not account for observing physical phenomena. He also stood by his research, saying he was "just as confident" in the work as he was a month ago. More data about K2-18b will come in over the next year which should offer a much clearer picture, Madhusudhan added. Even if the planet does have DMS, it is not a guarantee of life -- the chemical has been detected on a lifeless asteroid. However, many researchers do believe that space telescopes could one day collect enough evidence to identify alien life from afar. "We are the closest we have ever been" to such a moment, Welbanks said. "But we have to use the frameworks that are in place and build up (evidence) in a reliable method, rather than using non-standard practices and jumping the gun -- as has been done in this particular case," Nixon added. dl/jm/fec
