Update: of course it wasn’t aliens. A couple of years later, it’s fairly clear that it’s probably an “uneven ring of dust,” although some controversy remains. But I don’t think that takes anything away from the fun of realizing that this observation was the kind of thing we may find someday, if it’s possible to spot any signs of alien civilizations at all.
Maybe we’ve finally spotted aliens at work: a star system behaving super oddly. Really, really strangely. Probably not aliens, of course, but actually maybe. I think the story is genuinely exciting no matter how it turns out, and hypothesizing aliens is not just kooky wishful thinking. The absence of such artifacts in the cosmos wouldn’t be much stranger than finding them (see “Fermi Paradox”). And, importantly, we’ve only recently built the tools we needed to start looking… so … now that we have them, seeing something like this is actually kinda right on schedule!
Let me spell that out a little more…
It’s super sensible to be wary of using “because aliens!” to explain bizarre astronomical observations, of course, for good and obvious reasons: everything weird we’ve ever seen out there so far has turned out to just be nature being cool.
But our ability to spot the right kind of anomalies is changing fast, and space is so stupendously, mind-bogglingly vast that it really should be teeming with life (even if life is spectacularly fussy about where it lives), and if not why the hell not? If the life is out there, we “should” be able to spot signs of some of it, but not necessarily obvious signs. If aliens could rearrange constellations or make stars flash funky colours like galactic disco balls, we would have seen that by now, but maybe such things just aren’t possible even for the most advanced technologies.
The high end of alien engineering may well be “merely” stellar-scale: extremely impressive, but still rather hard to see from a distance, harder than spotting extrasolar planets, and we’ve only just learned how to confirm those, and we’re still only able to do that with the orbits that we can see edge on… and only the bigger planets, often in scalding hot orbits … and of those, how many would not only have life but clever, ambitious life that builds stuff so frackin’ big that it’s visible from many light years away using tech that’s just barely up to the job? Not terribly many, of course, so it’s completely unsurprising not to have seen one yet. But… this is exactly the time when we start to have a realistic shot at it.
If we keeping looking using these new tools, sooner or later we’re going to find someone’s big engineering project… unless we really are alone, which would be damn surprising too.