SETI@home's 21-year hunt for alien life leaves 100 unsolved signals

For over two decades, a groundbreaking project called SETI@home brought together millions of volunteers in the search for extraterrestrial intelligence. Running from 1999 to 2020, it harnessed the power of everyday computers to analyse radio signals from space. The initiative not only captured public imagination but also demonstrated how global collaboration could push scientific boundaries.

SETI@home launched in 1999 with an innovative approach: distributed computing. By tapping into the unused processing power of volunteers' computers worldwide, it processed vast amounts of data from Puerto Rico's Arecibo Observatory. Within a year, over 2 million users had joined the effort.

Over its lifetime, the project flagged around 12 billion anomalous signals. These were narrowed down to 100 candidates with traits resembling potential technosignatures—signals that might indicate intelligent life. After SETI@home concluded, the remaining candidates were passed to China's Five-hundred-meter Aperture Spherical Telescope (FAST) for further investigation.

The project's legacy extends beyond its findings. It proved that large-scale citizen science could accelerate research in ways previously thought impossible. No final conclusions have yet been drawn about the 100 signals, as ongoing analysis continues without a confirmed timeline for results.

SETI@home's work has left a lasting mark on both astronomy and public engagement with science. The 100 signals now under review by FAST represent the most promising leads from its decades-long search. While no definitive answers have emerged, the project's methods and global participation remain a model for future scientific collaboration.