Friday, September 2, 2016

No Aliens Yet

Back in May of 2015, scientists detected a signal that appeared to originate from space. The signal came from the direction of a sunlike star, prompting speculation that it may have been sent by an alien civilization. During the last year, SETI trained radio telescopes on the area of the sky from which the signal came, but found nothing. At the same time, Russian astronomers were busy analyzing the signal, and have determined that it most likely came from a military satellite rather than deep space.

Subsequent processing and analysis of the signal revealed its most probable terrestrial origin," astronomer Yulia Sotnikova wrote in an update published today (Aug. 31) by the Special Astrophysical Observatory of the Russian Academy of Sciences. "It can be said with confidence that no sought-for signal has been detected yet."

The May 2015 signal may have been caused by a Russian military satellite. Such a spacecraft was responsible for a similar detection during the Soviet period, Alexander Ipatov, director of the Institute of Applied Astronomy at the Russian Academy of Sciences, told the Russian news agency TASS.

False alarms like this one are all part of the process of hunting for extraterrestrial life. Researchers find something interesting, and then they — and their colleagues around the world — try to figure out what it means, said Seth Shostak, senior astronomer with the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California, who was not part of the detection team.

And that's exactly the point. It is practically a given that intelligent life must exist somewhere else in the universe, no matter how unusual a planet Earth turns out to be. We've only been generating strong radio signals for a hundred years or so, which is no time at all in galactic terms. The question is not whether intelligent life is out there, but whether it is close enough that signals can even reach us.

Meanwhile, KIC 8462852, the potential "alien megastructure" star, has gotten weirder. Back in November, it looked like the data supported the star being surrounded by a swarm of comets. But after looking over more data spanning several years, scientists concluded that the star had become progressively dimmer during the course of those observations.

We probably are still looking at a combination of natural factors producing the effect, but comets alone would not account for it. So now we're back at the possibility - mind you, still a pretty unlikely one - of the dimming being caused by an alien structure in orbit around the star. The lack of signals from the star system argues against that, but it's also true that aliens might communicate in some other way.

So the truth is out there, but it looks like it may take the next generation of space telescopes to find it. Personally, I've been interested in the possibility of alien life since I was a kid, and it's encouraging to see our experimental tools developing to the point where we can observe anomalies like this at all.

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