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Why it’s so hard for astronomers to discuss the possibility of alien life

The internet went crazy this week over a strange star observed by NASA's Kepler spacecraft

ESA

The internet has been abuzz this week over the possibility of intelligent alien life somewhere in our galaxy. This time, an article published by The Atlantic set off the storm. The story details how NASA's planet-hunting Kepler spacecraft has spotted a strange star in the Milky Way named KIC 8462852. The star exhibits weird fluctuations in its brightness, leading a few astronomers to propose — among many other ideas — that maybe a swarm of alien megastructures is orbiting around the object.

"I was fascinated by how crazy it looked," Jason Wright, an astronomer from Penn State University who studied the star, told The Atlantic. "Aliens should always be the very last hypothesis you consider, but this looked like something you would expect an alien civilization to build." Wright said he is working on a paper that explores the theory further.

"Aliens should always be the very last hypothesis you consider."

It's perhaps the least likely scenario to explain the star's behavior, but since the story's publication, there have been numerous articles suggesting that NASA has found complex alien life around KIC 8462852. "Astronomers believe bizarre light patterns from a star millions of miles away to be alien megastructures" offered one article, and another claimed: "Astronomers think they have found an alien megastructure." The headlines are completely ridiculous and misleading, according to astronomer Sara Seager.

"It’s just irresponsible reporting. Because if you take a look at the paper — the scientific paper the authors wrote — [that idea] is not really even in there," Seager, astronomer and planetary scientist at MIT, told The Verge.

Seager noted this has long been a problem for astronomy. Whenever astronomers talk about potential evidence for alien life, their statements are often overblown. It’s an unfortunate byproduct of the field, she said, because discussing how to find extraterrestrial beings is an important part of exoplanet science. "We definitely visit that question a lot: How will we know? What evidence does it take?" she said.

Artist rendering of NASA's Kepler spacecraft. (NASA)

Planetary scientists are always looking for signs that extraterrestrial beings may exist on planets elsewhere in the Universe. For example, finding gases on a planet that wouldn't normally belong there may indicate the presence of single-celled organisms. There are also discussions among researchers about how to spot intelligent life, too; perhaps they would try to communicate with us, possibly by constructing a big signal of some kind that our telescopes could see. "Think about people who are lost in the woods," said Seager. "They start a fire or show something very reflective. There are papers written about it: what would the aliens have to do to get our attention?"

No concrete evidence has ever been found to support the existence of alien life, but scientists still need guidance for the best places to look. The bizarre qualities of KIC 8462852, first described in a paper published by a Yale group called Planet Hunters, are what gave Wright the idea that this star could be a good target. The Planet Hunters' paper discusses how this object, observed by the Kepler spacecraft, differs from other stars with orbiting planets. Normally, when planets pass in front of their host star, they temporarily dim the star's light by a minuscule amount. This dip in brightness is often observed in patterns, indicating the planet's uniform path around the star.

Scientists still need guidance for the best places to look for alien life

KIC 8462852 also dips in brightness, but in a much more abnormal way; its brightness will dip by as much as 20 percent for irregular periods of time — anywhere between five to 80 days. That means something very large is passing around the star in a non-uniform pattern.

The Planet Hunters' study offers many different scenarios that could explain the abnormal light dipping. The main theory centers on a large group of comets that have been pulled in by the star's gravity. However, Wright, who helped the Planet Hunters group with their paper, told The Atlantic that he is working on an additional report to suggest that an alternative, unnatural scenario might be occurring. Wright explained later in a blog post that he has been working on a theory about how Kepler might be able to detect "planet-sized megastructures — solar panels, ring worlds, telescopes, beacons, whatever" that are orbiting planets. If they were large enough, they'd cause the huge light dips like the ones seen on KIC 8462852.

"One of the things that occurred to me is that a civilization that would build one megastructure would eventually build more. The star might be surrounded by them (a Dyson swarm)," wrote Wright in his blog post.

Wright goes on to say that he isn't claiming that's what's going on here, and suggesting otherwise is "overstating the evidence." However, when it comes to the SETI Institute — the Search for Extraterrestrial Intelligence — scientists need to focus on the "best targets." The Universe is a big place, so researchers are always looking for ways to narrow their search. Pointing our antennas at KIC 8462852 would be a better strategy than analyzing the many other millions of stars we know about.

"Something's going in front of the star, but we don't know what."

But in regards to the frenzy surrounding this particular star, Seager said that jumping to the alien conclusion is way too premature. Inexplicable stars like KIC 8462852 are observed all the time in astronomy. "It's correct that this star seems to be anomalous and unique in all of the Kepler star data, but there are other one-off objects like this in astronomy," said Seager. "Not all puzzles are solved right away. Something's going in front of the star, but we don't know what."

NASA also cautions not to get too enthusiastic, since Wright's paper on the alien theory hasn't even been published yet. "The paper, as far as I know is not yet accepted," said Dr. Steve Howell, a Kepler project scientist at NASA Ames Research Center. "We have this belief in the scientific community that until a paper is accepted, what’s said there and the results may change, so I think until this gets accepted we should scientifically be cautious. That’s kind of how things work."

Until that happens, Seager said speculating any further is just silly. "We love media attention; it's great for the field. But I just find this a little awkward."


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