In mid-October, the Kepler space telescope detected an irregular light pattern around a star, KIC 8462852, which is about 1,500 light years away from Earth. Excitement grew across the internet when it was announced an alien mega structure such as a Dyson sphere, a huge structure that gathers energy from the star, may have been the cause.
But as the astronomers stressed, alien should always be the last hypothesis, and for good reason. Scientists at SETI, the Search for Extraterrestrial Intelligence, listened in for alien radio signals using the Allen Telescope Array, a group of 42 telescopes designed to pick up radio waves from distant stars. Unfortunately, the search turned up no unnatural signals from a potential E.T.
SETI astronomers searched for two different types of radio signals, narrow range and broad range. In the narrow range, scientists searched for a ”hailing signal,” which is a signal sent out intentionally to broadcast their presence to the galaxy, as we humans have done in the past. This frequency is a relatively quiet area, low in natural radiation, making it ideal to listen in for. By searching in a broader range of frequencies, scientists were searching for signals that may have been inadvertently sent out by a civilization. Neither of these was detected around KIC 8462852, nicknamed Tabby’s star.
“The history of astronomy tells us that every time we thought we had found a phenomenon due to the activities of extraterrestrials, we were wrong,” said Seth Shostak of SETI, “but although it’s quite likely that this star’s strange behaviour is due to nature, not aliens, it’s only prudent to check such things out.”
One of the important rules of science though is that ”absence of proof is not proof of absence,” so it may still be possible that the strange light curves are being caused by aliens. However, this is very unlikely. As originally suggested, this phenomenon may be due to a shattered comet orbiting the star.
SETI will continue to monitor Tabby’s star for signs from an alien signal as the search for life beyond Earth continues.