Pretty much everybody knows that the galaxy is full of stars with planets, the idea that our solar system is somehow unique or even moderately special was put to rest a while ago. But what most people likely don’t realize is that one of the primary ways we determine if a star has planets is by watching it to see if they “blink” so to speak, if their light dims at a regular interval. We have some powerful telescopes, but it’s still basically impossible to make out planets in other star systems like we can look at Mars.
So, if a star dims slightly at regular intervals, we generally take that to mean that something is orbiting it, usually a planet. The largest gas giants, like Jupiter, are only capable of blocking about 1% of the light put out by any given star. There’s obviously a lot more science going on there that we won’t get into here. So, that in mind, it should be suitable interesting to read that the star KIC 8462852, which is 1,400 light years away, periodically dims by up to 20%, every few weeks or months.
We don’t know why that happens.
One hypothesis is that aliens in that star system have built mega structures which orbit that star, objects so big that they can block 20% of a star’s light. The SETI institute pointed their radio telescopes at the star for a few weeks to see if we could pick up and radio signals that would indicate intelligent life was at hand, but we haven’t found anything. It doesn’t mean that there aren’t aliens there, but we haven’t been able to detect them.
More likely there is some kind of naturally occurring phenomenon at work that we simply haven’t studied before. Astronomy is pretty much a science of finding something weird and seemingly unique, then studying it and finding out it has a totally logical, though no less interesting, explanation. So it’s probably not aliens.