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\n Is there anyone out there?<\/p>\n NASA\/SDO<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n We may have been missing signals from intelligent aliens because of solar wind. Researchers from the Search for Extraterrestrial Intelligence (SETI) Institute say this means we have been watching for the wrong type of signal, potentially failing to spot promising evidence of extraterrestrial life, but the chances of a future discovery are now higher.<\/p>\n The not-for-profit organisation carries out research to help prove the existence of alien life, which includes listening for extraterrestrial radio signals that cannot be explained by natural cosmological phenomena.<\/p>\n Such a signal was previously expected to be a sharp, distinct radio signal in a narrow frequency range. But the new research suggests that such signals that are sent from distant planets may end up being made fainter and wider in the frequency band \u2013 essentially blurred slightly \u2013 as they pass through the plasma winds of stars.<\/p>\n <\/p>\n Vishal Gajjar and Grayce Brown at the SETI Institute calculated the scale of the effect on radio transmissions from spacecraft in our own solar system, then extrapolated that to other stellar environments. They found that a 100 megahertz signal could be widened as much as 100 hertz \u2013 enough to \u201cfall below traditional detection thresholds\u201c. A space weather event can similarly increase the amount of broadening experienced by a signal by several orders of magnitude.<\/p>\n Simon George at the SETI Institute says that there is also increasing consensus that looking for narrow radio broadcasts accidentally beamed through space is not the way to spot distant life. \u201cThe idea that an intelligent civilisation would send out such signals is becoming dated, especially when you look at how communications and so forth have evolved since the 1960s,\u201d he says. \u201cThere has been a dramatic move towards broadband and spread-spectrum techniques as these can carry far more information.\u201d<\/span><\/p>\n \u201cOne way to view this is to treat Earth like an exoplanet being viewed by an alien civilisation, a theme I often hear around SETI,\u201d says George. \u201cThe point is, while Earth was a strong narrowband source in the 1960s, it is much less so now with a continuing downward trend. Of course, if an intelligent civilisation was intentionally sending out a beacon which is designed to be obvious and easy to detect, either for a \u2018we are here\u2019 message or some other alien purpose, then that is a different story.\u201d<\/span><\/p>\n John Elliott at the University of St Andrews, UK, says he chooses to see the news as the glass being half-full, rather than half-empty: it means previous searches may have missed evidence, but also means that future searches will be more likely to succeed.<\/p>\n \u201cIt\u2019s over 50 years that we\u2019ve been actively researching and that\u2019s a blink of the eye, isn\u2019t it, when you think about it,\u201d says Elliott. He says that it\u2019s not just the distortion of signals that hampered previous searches, but inadequate technology to spot and extract signals from the noise \u2013 something which is changing as computing power and AI becomes more powerful. \u201cUp until recently, we really haven\u2019t had the equipment, the computing power, to do anything really significant. We\u2019ve been grappling around a bit in the dark,\u201d he says. \u201cProject it forward another 1000 years, which is just another heartbeat, can you imagine what our technology is going to be like? It\u2019s going to be magic.\u201d<\/p>\n Eric Atwell at the University of Leeds, UK, was involved with SETI around the turn of the millennium, and quantifies the discovery as perhaps raising a 0.0001 per cent chance of finding an alien signal to 0.0002 per cent.<\/p>\n \u201cIt\u2019s still a very low likelihood,\u201d he says. \u201cI don\u2019t think they\u2019ve wasted their time. They have been trying things, and they\u2019ve got pretty strong evidence that what they\u2019re trying doesn\u2019t work, because they haven\u2019t found anything yet.<\/p>\n \u201cWhat they\u2019re doing is trying to detect strange signals which can\u2019t be put down to known astronomical features, but that\u2019s still a pretty hit-or-miss way of finding intelligent life,\u201d says Atwell.<\/p>\n He is sceptical that passively waiting for telltale evidence of life, accidentally broadcast, is the correct approach if we want to eventually talk to aliens. \u201cIf there really are aliens out there, and they want us to find them, they would send us a much more explicit signal,\u201d he says.<\/p>\n Other groups, such as the Messaging Extraterrestrial Intelligence (METI) organisation, have a different approach to finding alien life. They plan to actively broadcast signals to other planets, in case distant life is listening out for signals as we do.<\/p>\n Topics:<\/p>\n<\/section><\/div>\n