Moving right along: Signs of life? Kepler’s ‘Alien Megastructure’ star keeps getting weirder. Excerpt:
In the 4 years of Kepler’s primary mission, the star showed an unprecedented dimming of 3.5 percent. So not only did Kepler detect transient dips in brightness of up to 20 percent, there also seems to be a very definite downward trend in brightness throughout our observational history of the star.
No matter how you slice it, this is strange.
After studying photometric observations for other stars surrounding KIC 8462852, there’s no other star that shows such dramatic behavior. What’s more, there’s very few known phenomena that could be causing this. So once again, astronomers are clutching at straws in an effort to explain what is going on.
“Broadly speaking, the morphology of the light curve is generally consistent with the transit of a cloud of optically thick material orbiting the star,” Monet and Simon write in their paper. “The breakup of a small body or a recent collision that could produce a cloud of material could also plausibly produce a family of comets that transit the host star together as one group, explaining the light curve…”
However, like all rational explanations for the behavior of KIC 8462852, there’s an infuriating “but.”
According to the researchers, for the cloud theory to hold true, it would need to be orbiting the star at “impossibly large distances” from the star or would need to have a strange structure that increases in density as it transits across the face of the star. This poses a challenge and they say that the idea is far from complete.
In simple English: The odd behavior of this star is consistent with some huge amount of opaque material passing between us and the star. It’s impossible to say “yes, this is an alien megastructure” but it is also (at least, so far) impossible to say “no, this is not an alien megastructure.” (Note that it is overwhelmingly likely that this is not in fact an alien megastructure – but the odds of it being such are not zero.)
That’s how science works. It’s sometimes maddeningly tentative.
In this case, astronomers are entirely correct to be maddeningly tentative. The discovery of life outside of Earth would be probably the single most significant event of the modern scientific era; the discovery of advanced, intelligent life outside of Earth – say, the kind of life capable of building megastructures capable of blocking a significant percentage of a star’s output – would be gob-smackingly, amazingly, thunderously significant, with implications not only for science but for ethics, religion, and a host of other aspects of modern philosophy. That would be a discovery following which nothing, literally nothing, would be the same.
So, yes, in analyzing something like this, an abundance of caution is in order.