A star which was suspected to support intelligent life on an orbiting planet has been examined and dismissed. No one is orbiting KIC 8462852.
The search for extraterrestrial intelligence is a game of elimination. Cosmologists check stars and planets for signs of intelligent life, knowing the vast majority of searches will be fruitless. So when they see one that displays unusual characteristics that indicate life, like star KIC 8462852, it's an exciting moment.
SETI International, a new organization which works to find evidence of intelligent life on other planets (not to be mistaken with the SETI Institute of the U.S.), focused on the star because NASA reported that the light emerging from it was pulsing at an unusual rate—a rate that could be influenced by artificial lights, such as a laser beam sending a "we're here" signal out into space.
The star's light dims and brightens so dramatically—22 percent at times, as opposed to the 1 percent expected when a large planet passes over a star—that an artificial light source seemed highly probable. So, the SETI astronomers used photometers to measure the intensity of the light over six days, measuring and analyzing the quavering star. But the results won't excite E.T. fans.
"The hypothesis of an alien megastructure around KIC 8462852 is rapidly crumbling apart," said Douglas Vakoch, president of SETI International, in a press release. "We found no evidence of an advanced civilization beaming intentional laser signals toward Earth."
Instead, the scientists now hypothesize that the irregular brightening and dimming is caused by fragments of comets coming and going as they pass in orbit around the star. Still, even this observation may help SETI International, and organizations like it, to fine-tune their process for finding our celestial relatives.
"If some day we really detect a signal from an extraterrestrial civilization, we need to be ready to follow up at observatories around the world, as quickly as possible," said Vakoch.
No kidding. According to Vakoch, any signal received from KIC 8462852 today would have been beamed out right after the fall of the Roman Empire.
The study which documents these findings was published this week in The Astrophysical Journal Letters.
Photo: Tim Hall | Flickr