You could hear a pin drop. That’s how quiet the cosmos appears to be despite news that a year-old spike in radio signals could point toward an intelligent extraterrestrial civilisation.
The signal, detected on 15 May 2015 by a radio telescope operated by the Russian Academy of Sciences, was so powerful it evoked a radio beacon built by an intelligent civilisation. It appeared to originate from the star HD 164595, in the constellation Hercules, which has one known planet roughly the size of Neptune.
SETI astronomers across the globe have jumped into action to try to confirm that signal. But so far, there’s no sign of ET.
In an informal report posted online overnight, Steve Croft at the Berkeley SETI Research Center reported how the Breakthrough Listen Initiative — a project that uses radio telescopes across the world to look for signs of intelligent life beyond Earth — searched for the signal in archived data. Unfortunately, no counterparts were spotted in the Naval Radio Astronomy Observatory Catalog — a null result, which is unexpected if the signal is real.
This suggests that the Russian team was “either extremely lucky to detect this source in their observations, or that the transient is due to local interference or other calibration issues”, write Croft and his colleagues.
Just in case, the team aimed the Green Bank Telescope in West Virginia toward the star on Sunday night. They didn’t detect any ongoing emission from the direction of the star, but they are careful to point out that this doesn’t mean there’s no extraterrestrial civilisation there.
Seth Shostak of the SETI Institute and his colleagues also observed the star on Sunday and Monday nights with the Allen Telescope Array in northern California. The first night turned up empty and Shostak hasn’t yet received the results from the second night.
And Douglas Vakoch, the president of METI International — a group that isn’t just looking for signs of intelligent extraterrestrial life, but would like to send messages to them as well — has made plans to swing the Optical SETI Observatory in Panama toward the star. Unfortunately, a series of thunderstorms has hit the area and are forecast to continue for several days.
“Once the skies clear, we will have about an hour shortly after sunset each night to search for signals,” he says.