Not Aliens ... Weird Radio Signal from Star Likely Has Duller Explanation

Astrogeology, Asteroids, Robots, Space Flight & Extraterrestrial Matters

Date posted: 07/21/17

Mike Walls reports later that the strange radio signal that seemed to emanate from a small nearby star probably came from Earth-orbiting satellites, astronomers say. Late last week, researchers announced that, on May 12, the 1,000-foot-wide (305 meters) Arecibo radio telescope in Puerto Rico detected a bizarre radio signal in the vicinity of Ross 128, a red dwarf star that lies just 11 light-years from Earth. The signal was theoretically consistent with a transmission from an alien civilization, the astronomers said, though they stressed that hypothesis was at the bottom of many other explanations. Indeed, they pegged the leading candidates as flares from Ross 128, emissions from some other object in the same field of view as the star, and a burst from one or more high-orbiting satellites. Now, follow-up observations, by Arecibo, as well as the Green Bank Telescope in West Virginia and the Allen Telescope Array (ATA) in northern California, point to this last hypothesis as the most likely, team members said. The best explanation is that the signals are transmissions from one or more geostationary satellites, Abel Mendez, director of the Planetary Habitability Laboratory at the University of Puerto Rico, wrote in a statement today (July 21). (Geostationary satellites circle Earth at an altitude of about 22,300 miles, or 35,800 kilometers.) This explains why the signals were within the satellite frequencies and only appeared and persisted in Ross 128. The star is close to the celestial equator, where many geostationary satellites are placed, Mendez added. This fact, though, does not yet explain the strong dispersion-like features of the signals (diagonal lines in the figure) However, it is possible that multiple reflections caused these distortions, but we will need more time to explore this and other possibilities. But even though it is likely that the Ross 128 signal has a prosaic explanation, scientists should still follow up on similar detection. Read on..