Humanityโs radio bubble.
Also mostly irrelevant, because at the rate a radio broadcast attenuates, beyond 20 or 30 light-minutes out from earth, unless you know exactly where to point a very large and powerful detector, information theory (a pretty damn hard and fast limit) says that nothing ever made could detect any non-directed normal-power broadcast.
So aliens in Alpha Centauri and beyond arenโt watching Howdy Doody because the energy from that and anything else ever broadcast from earth is utterly and completely subsumed in and by the background noise of the universe.
Thereโs been nothing weโve done that anyone not in this solar system could even know about in principle, with any technology.
It’d require a exawatt or maybe zettawatt laser to send a message to any place likely to harbor life, and then we’d have to know exactly where to point the device.
Kind of casts a new light on the likelihood of SETI detecting alien life, really.