ALMA High‑Frequency SETI Search Finds No Alien Signals
Researchers led by Louisa Mason of the University of Manchester used archival data from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to conduct the first SETI survey at millimetre and sub‑millimetre wavelengths, well above the traditional “water‑hole” band of 1.42–1.66 GHz. By analysing two narrow frequency windows in ALMA Band 3, the team searched for technosignatures—extremely narrow artificial radio signals—that would stand out from natural astrophysical emission. No convincing extraterrestrial technosignature was found; all detected signals were attributable to human‑made interference. The results, presented at the Royal Astronomical Society’s National Astronomy Meeting in Birmingham (2026), demonstrate that higher‑frequency bands can be searched effectively and set new upper limits on how common powerful transmitters might be in the Milky Way.
Entities: Atacama Large Millimeter/submillimeter Array (ALMA) · Atacama Large Millimeter/submillimeter Array (ALMA) · Chile · Louisa Mason · Royal Astronomical Society · SETI (Search for Extraterrestrial Intelligence) · University of Manchester
Claims
What the coverage asserts, and how well corroborated each claim is across sources.
- [● 10 SOURCES] The ALMA analysis searched for technosignatures at high radio frequencies that have been largely unexplored by previous SETI projects. (new)
- [○ 1 SOURCE] The Green Bank Telescope conducted a ten‑year SETI search covering more than 70,000 star systems and over 105 million narrow‑band signal candidates. (Study summary)
- [○ 1 SOURCE] About 99.5 % of the detected signals were automatically classified as human‑made interference. (Study data)
- [○ 1 SOURCE] The Green Bank Telescope surveyed the 1.15–1.73 GHz frequency range for narrow‑band signals. (Study methodology)
- [○ 1 SOURCE] The Green Bank Telescope search found no convincing extraterrestrial technosignature. (Study summary)
- [○ 1 SOURCE] The study established stringent upper limits on how common powerful radio transmitters are in the Milky Way. (Study conclusion)
- [● 10 SOURCES] No alien signals have been detected in the ALMA high‑frequency search so far. (new)
- [● 10 SOURCES] Louisa Mason of the University of Manchester presented an analysis of ALMA archival data targeting millimetre and sub‑millimetre frequencies. (new)
- [● 10 SOURCES] All detected signals were identified as human‑made interference; no technosignature candidates remained. (new)
- [● 10 SOURCES] The search examined two narrow frequency windows within ALMA Band 3 observations. (new)
- [● 10 SOURCES] The results were presented at the Royal Astronomical Society’s National Astronomy Meeting in Birmingham in 2026. (new)