Sadly, it would not be possible to discern manmade radio transmissions from further than a few light-days/weeks. Also, as communication capacities increase, mo

Sadly, it would not be possible to discern manmade radio transmissions from further than a few light-days/weeks. Also, as communication capacities increase, more and more of that is moving into cables and not radio transmitters. High-power Earth-Satellite and Earth-Earth transmitters are being replaced with low-power point-to-point wireless links. The power of radio traffic leaking off the Earth is not growing very much, if at all.