This means that for the first time, we can do more than just randomly listen for signals from alien civilizations, we can actually start targeted searches for radio signals coming from the planetary systems where they might be living. And if there is advanced intelligent life in these planetary systems, it seems likely that we'd be able to spot it, because just like humans — theoretically, at least — aliens would likely start by colonizing multiple planets in their home system. If they do that, they'd need interplanetay communications, and that's the type of thing we might be able to spot with radio telescopes from Earth.