In 1995, the computer scientist David Gedye had an idea that could only originate at a cocktail party. What if the world’s personal computers were linked together on the internet to create a virtual supercomputer that could help with SETI, the search for extraterrestrial intelligence? The network would be able to sort through the massive amounts of data being collected by radio telescopes, seeking signals that might point to an alien civilization around another star. A distributed supercomputer sounded outlandish at the time, but within four years, Gedye and his collaborators had built the software to make it a reality. They called it SETI@home.
On Tuesday, researchers at the Berkeley SETI Research Center announced they would stop distributing new data to SETI@home users at the end of March. It marks the culmination of an unprecedented 20-year experiment that engaged millions of people from almost every country on earth. But all experiments must come to an end, and SETI@home is no exception. So far, the researchers at Berkeley have only been able to analyze small portions of the SETI@home data. They had to hit pause on the public-facing part of the experiment to analyze the full two decades of radio astronomy data they’ve collected to see what they might find.
“For 20 years, there’s been this fight between keeping the project running and getting the results out to the scientific community,” says Eric Korpela, the director of SETI@home. “At this point, we can’t even be sure that we haven’t found anything because we’ve been doing most of our data analysis on small test databases rather than the whole sky.”
Officially launched at Berkeley on May 17, 1999, the SETI@home initiative helped address one of the biggest challenges in the search for extraterrestrial intelligence: noise. Professional alien hunters are in the business of searching for weak radio signals in a vast sky washed out by interference from satellites, TV stations, and astrophysical phenomena like pulsars. This means they are fundamentally grappling with a big data problem—they’re looking for a single signal sent by ET floating on a vast ocean of radio flotsam.
Filtering through all this data requires computing power—and lots of it. More processors crunching data from outer space means a more sensitive analysis of more signals. By borrowing unused processing power from personal computers around the world, SETI@home could plow through radio telescope data faster than ever before. When a computer was idle, the SETI@Home
