The Search For Technosignatures: Widening Our Search From Radio Signals

Thursday - September 28 2023, 01:27 UTC - 1 year ago

In a recently released report, a team of Caltech and NASA Jet Propulsion Laboratory astronomers argue for widening our search from primarily radio signals to all Technosignatures—telltale signs of technological civilizations. They suggest using AI to search for any outliers in the data, from radio signals to unusually bright or flickering objects. Furthermore, the team states that SETI has suffered biases due to limited resources, which has resulted in the assumption that technological civilizations would choose to signal others civilizations "like us" with radio emission.

My college laptop was slow. It didn't help that the internet was too. Neither fact distracted me from two crucial tasks: downloading music and searching for aliens. The former was a study in patience—tracks spooled out at glacial speeds—the latter a (lazy) labor of love. Scientists had the genius idea of parceling out astronomical data to laptops where a screen saver could comb through them for alien radio signals .

I'm sad to report: None found. But a lot has changed since then. Computers are faster, software is smarter, and the amount of astronomical data—across the spectrum not to mention gravitational waves—has exploded. It's worth asking: If the data was too much for astronomers to process years ago, what potentially revolutionary signals have we missed since then? In a recently released report, a team of Caltech and NASA Jet Propulsion Laboratory astronomers, led by Joseph Lazio, George Djorgovski, Curt Cutler, and Andrew Howard, argue we can't know for sure unless we change our search strategy to match the times .

Whereas the search for extraterrestrial intelligence (SETI) has been focused on the detection of radio signals—think Jodie Foster with a pair to headphones in the movie Contact—we've since recorded an abundance of data from across the sky and developed tools that can comb it for subtle outliers, from radio signals to unusually bright or flickering objects. "Ten, twenty years ago, we didn’t have this explosion of artificial intelligence and computation technologies," Anamaria Berea, a computational social scientist at George Mason University not involved in the project, told Wired .

"Now they can be used also for archived data."The idea is two-fold: First, let's widen the search from primarily radio signals to all technosignatures—that is, any telltale signs of technological civilizations, intended or not, from advanced communications to megastructures. Second, let's search for those technosignatures in all current and future observations by training algorithms to spot aberrations and outliers in the data .

A key benefit of such an approach is we "let the data tell us what is in the data," the team writes. Instead of plastering our own biases on the search, we can simply look for anything weird and then take a closer look to figure out why it's different.At the beginning of the last century, the team say, Marconi, Tesla, and Edison all believed they'd detected radio signals from Mars. They were smart, and wrong .

Their judgement was clouded by scientific and technological limits—they didn't know signals in the band detected couldn't get through Earth's atmosphere—and cultural biases—there was a strong popular interest in Mars at the time.SETI, constrained by resources and availability of data, has suffered biases too. Astronomers could only do so many searches on a limited range of instruments, so they had to decide which lines of inquiry were most valuable .

Assumptions have commonly included the idea technological civilizations would choose to signal others civilizations "like us" with radio emission.