We’ve all wondered at one point or another if intelligent life exists elsewhere in the universe. “I think it’s very unlikely that we are alone,” says Eric Korpela, an astronomer at the University of California Berkeley’s Search for ExtraTerrestrial Intelligence (SETI) Research Center. “They aren’t right next door, but they may be within a thousand light years or so.”
Korpela is project director of the SETI@home project. For more than two decades, that project harnessed the surplus computing power of over 1.8 million computers around the globe to analyze data collected by radio telescopes for narrow-band radio signals from space that could indicate the existence of extraterrestrial technology. On 31 March 2020, SETI@home stopped putting new data in the queue for volunteers’ computers to process, but it’s not the end of the road for the project.
Now begins the group’s next phase. “We need to sift through the billions of potential extraterrestrial signals that our volunteers have found and find any that show signs of really being extraterrestrial,” says Korpela. That task is difficult, he adds, because humans “make lots of signals that look like what we would expect to see from E.T.”
The primary indicator that his team uses to determine whether a signal might be extraterrestrial is whether that signal remains stable in the sky. “So if we look at a spot in the sky and see a signal, and then come back and look at the same spot a month later and it’s still there, then maybe we have something,” he says. In addition, he notes: “Nearby signals, from a radar system, for example, typically are seen at many positions on the sky, so if we think we’ve got something, we check to see if the same signal ever came from somewhere else.” SETI@home volunteers have returned about 15 TB of data to analyze, Korpela reports.
As SETI@home moves into the analysis phase, the search for alien life continues elsewhere. The SETI Institute, a non-profit research organization (which has nothing to do with SETI@home) is collaborating with the National Radio Astronomy Observatory to employ the world’s most versatile radio telescope, the Very Large Array (VLA), to enable a SETI survey that will be far more powerful than any previous searches.
The VLA is comprised of 27 dishes, each 25 meters in diameter, used by astronomers to study known cosmic objects and phenomenon. The SETI Institute is developing a new interface called COSMIC (Commensal Open-Source Multimode Interferometer Cluster) that will be able to access raw data from each antenna, routing it through signal processing software to search for extraterrestrial technosignatures in real-time.
“COSMIC SETI aims to provide a new digital processor at the VLA telescope which will enable SETI research using modern, off-the-shelf computing,” says Jack Hickish, who will lead the effort. “The SETI capability will be commensal, [so] we will be able to [continue our work] while other scientists are using the telescope for their own projects.”
The system is expected to process in excess of 300 GB/second of data. The project is also entirely open-source, and all the software developed for COSMIC will be made available to other researchers to help in their own SETI (or non-SETI) work. Though the COVID-19 pandemic has resulted in some delays, Hickish hopes to get the first pieces of hardware deployed to the telescope this year.