CNN reported that astronomers engaged in the search for extraterrestrial intelligence (SETI) are training their instruments on a star around 94 light years from Earth after a very strong signal was detected by a Russian telescope.
An international team of researchers is now examining the radio signal and its star, HD 164595 — described in a paper by Italian astronomer Claudio Maccone and others as a “strong candidate for SETI” — in the hopes of determining its origin.
“The signal from HD 164595 is intriguing, because it comes from the vicinity of a sun-like star, and if it’s artificial, its strength is great enough that it was clearly made by a civilization with capabilities beyond those of humankind,” astronomer Douglas Vakoch, president of METI International, which searches for life beyond Earth, tells CNN.
Paul Gilster of the Tau Zero Foundation, which conducts interstellar research, said that if the signal was artificial, its strength suggested it would have to come from a civilization more advanced than our own. Such a civilization would likely be Type II on the Kardashev scale, an attempt by the Soviet astronomer of the same name to categorize various technological stages of civilizations. At present, our own species is somewhere near Type I on the scale, whereby a civilization is able to harness all the energy available to it on its own planet, including solar, wind, earthquakes, and other fuels.
A Type II civilization would be able to harness the entirety of the energy emitted by its star, billions of billions of watts. Doing so would require a colossal undertaking, likely the construction of some kind of superstructure, such as a giant sphere or swarm of super-advanced solar panels popularized by astronomer Freeman Dyson that could catch and store all radiation put out by the sun. Scientists believe superstructures are probably our best chance of detecting alien life unless they are actively trying to communicate with us. A Dyson sphere was one of the solutions suggested to the peculiar light fluctuations detected around Tabby’s Star, which caused great excitement when they were detected last year.
In a statement, Seth Shostak, a senior astronomer with the SETI Institute, said that “it’s hard to understand why anyone would want to target our solar system with a strong signal.” The SETI Institute is also examining HD 164595, using the Allen Telescope Array in California. So far, the team has not found any signals to match those originally detected by the Russian telescope, but Shostak notes that “we have not yet covered the full range of frequencies in which the signal could be located.” “A detection, of course, would immediately spur the SETI and radio astronomy communities to do more follow-up observations.” Shostak writes that “of course (it’s) possible” the signal could be from an extraterrestrial civilization, but without confirmation, “we can only say that it’s ‘interesting’.”
