NASA might have solved deep space ‘alien megastructure’ mystery

26 Nov 2015

Comet image via ASA/MSFC/MEO/Cameron McCarty

Once touted as a potential ‘alien megastructure’, the bizarre reading surrounding a distant star has unsurprisingly been narrowed down to most likely being the result of swarming comets.

The star that spurred on the alien megastructure speculation was KIC 8462852, which created quite a stir last month after a study found that its light dimmed dramatically twice in 2011 and 2013, defying many scientific explanations.

While NASA never considered the idea that extraterrestrials had built a Dyson Sphere around the distant sun, it had narrowed it down to a few likely scientific answers.

And now, according to a recently published report, the answer is most likely a group of comets swarming around the star, rather than the alternative, which suggested a previously-destroyed planet or group of asteroids.

To help them narrow down the possibility of swarming comets, the study, led by Massimo Marengo of Iowa State University, wanted to analyse the surrounding infrared light, which, if a planetary collision or break-up occurred, would show up on NASA’s telescopes due to the warm dust that would be omitted by a collision.

Comets in front of star

An illustration of the comets passing KIC 8462852. Image via NASA/JPL-Caltech

This, the team said, would suggest that a whole family of comets is traveling on a very long, eccentric orbit around this star.

The first blocking of the star’s light in 2011 would suggest at the head of the pack would be a very large comet, followed by the rest of the comet family in 2013 appearing as a band of varied fragments lagging behind to block the light again.

Talking about this discovery, Marengo compares the bizarre findings to those made by Irish astrophysicist Jocelyn Bell Burnell and her discovery of pulsating radio stars, known as pulsars.

“This is a very strange star,” he said. “It reminds me of when we first discovered pulsars. They were emitting odd signals nobody had ever seen before, and the first one discovered was named LGM-1 after ‘Little Green Men’.”

Keeping the mystery alive somewhat, however, Marengo added: “We may not know yet what’s going on around this star, but that’s what makes it so interesting.”

Colm Gorey was a senior journalist with Silicon Republic