Since TV & radio there would have been broadcast most strongly quite horizontally out around from towers, while only rather weakly unintentionally up above (uselessly) into space, those received best and strongest here at some selected time would have come from places nearer the visible edge of the alien planet. So for us this should help getting the strongest best received broadcasts at some selected time out of that planet's days thus effectively narrowed down to those from one or not many various alien languages from their nations then near that planet's edge circle. Thus narrowing down at each such local day time to one stronger broadcast frequency might nicely isolate to just a single alien nation's language TV/radio broadcasts for some of us to study.
Possibly additional helpful filtering for just one broadcast place can be done by filtering for polarization direction, which should come different from different broadcast towers at different angles around near the planet's edge.
While studying alien TV found from a distant world by a huge TV & radio effective in-space telescope, it would be wonderful if some alien TV programs are found which had been intended to help their children learn, like some daily Earth programs sometimes even showing spelled words being carefully expressed, maybe fitting some shown activities, and maybe the spelled highlighted letters voiced. How about that! Their education programs then helping educate us!
If maybe from 50 light-years away, if finally the aliens seem safe to associate with, we could eventually prepare and have well aimed there a repeated simple friendly TV greeting program which the aliens there might eventually detect and grow fascinated watching. We would carefully strongly tightly aim the TV repeated greeting to where their planet must be orbiting when each repeat would reach there in a half century. This could become the start of most interesting alien communications, though taking a century to get a response back.
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