The ATA at the Hat Creek Radio Observatory

Central to this work is the Allen Telescope Array (ATA), a radio interferometer in Northern California designed specifically for SETI and radio astronomy, owned and operated solely by the SETI Institute. Researchers use the ATA to scan the sky for narrowband radio signals, potential technosignatures that could arise from extraterrestrial technologies. Advanced signal processing, machine learning, and real-time computing techniques sift through enormous volumes of data to identify patterns not easily explained by natural astrophysical sources or human-made interference. Researchers are also exploring a broader range of potential technosignatures, including pulsating radio beacons and transmissions that defy known astrophysical propagation laws.

LaserSETI

Scientists search for technosignatures across the entire electromagnetic spectrum, not just in radio waves. One example is LaserSETI, a SETI-Institute-based project designed to detect ultrashort optical flashes lasting just a few nanoseconds (a billionth of a second), with no known natural origin. LaserSETI aims to establish a global network of high-speed imaging systems capable of continuously monitoring the entire sky for these fleeting events. Other optical SETI initiatives include the search for signs of large-scale alien engineering, such as “megastructures" orbiting stars. Unusual dips in a star's brightness—light curves that don’t match patterns from natural phenomena like exoplanet transits—could reveal these technosignatures.