>>> What if it's not directional but broadcast? How much power do the
>>> 200ly-far aliens need to send a radio signal covering an entire
>>> hemisphere*, so that a reasonable amount still reaches us (or rather
>>> SETI's antenna)?
>>
>> That would be 7 TW. Which is the amount of power you can generate with a
>> solar array 150 km x 150 km* in size (assuming 24% efficiency). That 
>> would
>> be a bit more than our society could afford to spend on trying to
>> broadcast our position.

Good info, thanks!

Post a reply to this message