Humans May Only Have 41,000 Years to Catch Signs of Aliens Before They Fade
So long as humans have wondered about other forms of intelligent life in the universe, we’ve hoped E.T. would phone home. But so far, no one has ever called. Even our most powerful antennas have only picked up false positives and radio silence. Could it be because any hypothetical civilizations made of beings with brains to rival our own have long since vanished, with even any advanced technosignatures they might have left behind turned to nothing more than space dust?
Breakthrough Listen is hoping to figure that out. It is the largest ever SETI (Search For Extraterrestrial Intelligence) initiative on Earth, and it not only surveys the million closest stars to our planet, but scans the entire galaxy and literally listens for messages from any beings out there who might be trying to communicate with us. Some of its spectroscopic instruments are hypersensitive enough to detect a laser with no more energy than a lightbulb from 25 trillion miles away.
If that little energy can show up at such a distance, it seems like it should be only a matter of time before a megastructure like a Dyson swarm—satellites arranged around a star to harvest its energy or send intergalactic messages—could be found. (That is, if they exist at all. The jury is still very much out on that one). The question is whether we have that time. If you ask one theorist, we might only have about 41,000 years to find a swarm large enough to surround a star the size of the Sun before it falls apart completely.
