It’s been called the “most mysterious star in our galaxy.” From Earth, KIC 8462852 has appeared as a massive dimming and swelling of light, much more pronounced than what scientists have seen from planets passing in front of hundreds of other stars.
Could this dimming, as some suggest, be caused by massive structures built by an advanced alien civilization to harness the star’s energy? Or are they merely comet fragments? Astronomers suspect the latter, but that mystery has sparked a global hunt for scientific clues and ignited an Internet sensation. Social media exploded with kitschy web articles and “Star Wars” Death Star memes when news of the mystery star broke earlier this month.
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To a group of Northern California scientists who have spent years combing the sky for radio signals from another world, this might be the needle in the galactic haystack they’ve long been looking for. Their massive array of radio telescope dishes in rural Shasta County is now pointed at that distant star, some 1,480 light years from Earth.
“If in fact there are intelligent beings out there who created huge structures in space, maybe they’re also trying to send an intentional, powerful signal to us to capture our attention,” said Douglas Vakoch, director of interstellar message composition for the nonprofit SETI institute, which stands for Search for Extraterrestrial Intelligence. “Maybe there’s a beacon out there. That’s what we’re looking for.”
Vakoch and other astronomers are quick to note that the odds are low that the readings are from anything other than a natural phenomenon, but a long shot is better than none at all.
The array of 42 dishes near the remote town of Hat Creek, tied together through fiber-optic cable, are acting as a single giant ear listening for any radio signal possibly being beamed by another civilization. SETI researchers watch the data roll in from their Mountain View office, much like in the 1997 science-fiction film “Contact” that loosely depicted the group’s scientist co-founder, Jill Tarter, in the character portrayed by Jodie Foster.
Hat Creek was chosen for the telescope site because of the lack of radio interference from human civilization there. The last of its 42 dishes was installed in 2007, and the hunt for alien life began in 2009. The global nonprofit research center, SRI International, took over the observatory in 2012, allowing academics and nonprofit and government agencies to study outer-space radio emissions. The SETI Institute still uses the array to conduct its own research, often in conjunction with NASA’s planet hunters.
The investigation into the mystery started with NASA’s Kepler satellite, which launched in 2009 with a mission of finding new worlds. The spacecraft monitors light radiating off nearly 150,000 stars in the Milky Way galaxy between what we on Earth see as the swan-shaped Cygnus and harp-shaped Lyra constellations.
The satellite has been remarkably successful at finding new planets, and those monitoring Kepler have confirmed more than a thousand of those discoveries. Vakoch said around 20 percent of those planets are roughly the size of Earth and just far enough from the star they’re orbiting to have the potential to hold liquid water – a possible indicator of life.
The worlds become visible when they pass in front of the star they orbit, slightly dimming the light that shines to Earth. Vakoch said that if someone on a distant planet was looking back at us using the same method, “every time the Earth passes between our sun and their star they would see a slight dimming, every 365 days.”
“So we know there’s a lot of real estate out there that could be inhabited,” Vakoch said. “But what we don’t know is if there is any life out there.”
When KIC 8462852 was flagged for further review, researchers noted the outsized amount of dimming there. Vakoch said even the largest planets dim the light from their star by less than 1 percent.
“What we’re seeing looking at this star is at times there is dimming of more than 20 percent,” Vakoch said. “The other thing that’s odd is that the dimming isn’t regular. It’s not like every year something goes around and there’s the same dimming. That’s what has astronomers trying to figure out this puzzle of what is it that is actually around this star.”
The mostly likely explanation, researchers say, is that comet fragments are orbiting the star system and that the gravity from another nearby star is pulling them toward KIC 8462852.
If so, Vakoch said, it’s an incredibly rare bit of luck that the satellite would happen to spot this process in action.
“That would be a real fluke chance,” Vakoch said. “On the other hand, the Kepler mission is looking at 150,000 stars, and so sometimes events that are incredibly rare will be captured.”
Vakoch said that some have suggested the objects could be what are known in speculative science as Dyson Swarms. They’re named after theoretical physicist and mathematician Freeman Dyson who once suggested that a technologically advanced civilization could build massive structures near a star or an entire sphere around it to harness its energy. The star is so far away that the light we’re seeing now was emitted nearly 1,500 years ago, around the time of the Roman Empire’s fall.
“In order to pick up a signal it has to be directly beamed at us,” Vakoch said. “The Klingon version of Gilligan’s Island is not going to reach Earth. The only way that experiment works is they are pinpointing us, and presumably a lot of other stars as well, and really wanting to make contact.”
Steve Howell, a Kepler project scientist with NASA, cautioned last week not to get too optimistic.
In an online Reddit forum, Howell said it wasn’t the first time planet hunters got excited about the possibility of extraterrestrial contact.
Another star, KIC 4110611, also had an odd light curve.
“After a few years of working to find out why, it turned out to be a five-star system,” Howell said. “It was unique, but not alien structures.”