Subject: What sources might generate a 1 Hz radio wave, that's 3 x 10e8 meters long?

I am developing curriculum materials on the electromagnetic spectrum and 
want to make 1 Hz my starting point.

Kids would really grove on a wave that reached almost to the moon, 
and better understand the relationship between frequency and the 
speed of light.

Am I correct in supposing that a 1 Hz alternating current would 
generate such a wave?

How might such a wave be detected or measured? A radio dish or large 
array would be much to small, no?

Thanks for your help.

Re: What sources might generate a 1 Hz radio wave, that's 3 x 10e8 meters long?