Ross 128: Scientists Solve Mystery of Radio Signals Coming from Nearby Star

Ross 128 is a small red dwarf star in the constellation of Virgo. ESA/NASA

Earlier this week, astronomers detected some odd signals seeming to come from a star 11 light-years away, known as Ross 128. The researchers at the Arecibo Observatory in Puerto Rico were attempting to learn more about planets and objects orbiting a group of red dwarf stars, including Ross 128. During this time they found a strange transmission that they couldn't at first explain, which gave rise to some speculation it could be alien in origin, though that possibility was ruled out.

"We realized that there were some very peculiar signals in the 10-minute dynamic spectrum that we obtained from Ross 128," Abel Méndez, director of the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo, wrote in a blog post at the time. "The signals consisted of broadband quasi-periodic non-polarized pulses with very strong dispersion-like features."

The researchers further analyzed the signal, and have determined that it most likely came from one or more geostationary satellites. "This explains why the signals were within the satellite's frequencies and only appeared and persisted in Ross 128; the star is close to the celestial equator where many geostationary satellites are placed," Méndez writes in a new post. "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." The Arecibo scientists collaborated with researchers from the SETI Institute to reach their conclusion.

The astronomers have dubbed the transmission the "Weird! signal," in honor of the Wow! signal, a 1977 transmission that couldn't be explained at the time, and some thought could be from aliens, but which likely derived from a comet. In the process of trying to find out where the Weird! signal might have come from, they sent out an informal survey to more than 60 astronomers and hundreds of others. These respondents seem to favor the idea that the transmission derived from "stellar activity" or some "other astronomical source," though "a satellite" came in as the third-most-likely explanation. A non-negligible number of people responded that it might be from aliens.

"The Planetary Habitability Laboratory of the University of Puerto Rico at Arecibo made many new friends from this experience," Méndez writes, noting that it was "a great experience of open science." He concludes that "we all need to continue exploring and sharing results openly.