Here’s a problem:
New research by the Silicon Valley-based SETI Institute (search for extraterrestrial intelligence) suggests tempestuous space weather makes radio signals from the distant cosmos harder to detect.
The organization, which is partly funded by Nasa, said stellar activity such as solar storms and plasma turbulence from a star near “a transmitting planet” can broaden otherwise ultra-narrow signals. That spreads the power of any such transmission across more frequencies, the institute’s scientists say, which makes it more difficult to detect using traditional narrowband searches.
And:
The new research, they say, highlights an “overlooked complication”: even if an extraterrestrial transmitter produces a perfectly narrow signal, it may not remain narrow by the time it leaves its home system.
“Plasma density fluctuations in stellar winds, as well as occasional eruptive events such as coronal mass ejections, can distort radio waves near their point of origin, effectively ‘smearing’ the signal’s frequency and reducing the peak strength that search pipelines rely on,” a statement accompanying the finding states.
In layman’s terms it means that, however unlikely a scenario, the institute believes aliens might be out there, and could be trying to talk to us. But if they are, unpredictable weather conditions have garbled the messages, and we simply cannot hear them.
And:
Brown said the findings meant space listeners would have to rethink the long-established mechanics of the search for alien lifeforms, including conducting future observation surveys at higher frequencies.
“By quantifying how stellar activity can reshape narrowband signals, we can design searches that are better matched to what actually arrives at Earth, not just what might be transmitted,” she said.
All very interesting – a pity the article then takes a predictable left turn into UFO’s and the noise around release of some files on unexplained anomalous phenomena, which frankly is beside the point. What would be more interesting would be some outline of the means by which scientists could work around this newly realised challenge. As always with space science and exploration the reality is that all this is difficult – transmitting signals across light years is a massive endeavour.
As it happens radio and other signals are expanding outwards, up to 200 light years from Earth but, as this piece notes – the ionosphere of this planet ‘garbles’ many of those, and even those that survive: (like Earth-space communications), by the time they’re 100 light-years away, are so attenuated and weak that they’re basically undetectable anyway.
More modern communications media tend to be ‘quieter’ and less easily detectible. That might be no bad thing.