We could never send a Morse signal to the Moon or Mars - the aerial mast necessary for that would be reaching out of the atmosphere and you would need to burn amount of coal equivalent Mt Everest to power it!

(Paraphrasing a bit but I do remember reading such an article, where they explained how it was nonsense to send interplanetary messages with their long wave omnidirectional antennas and inefficient early radios, including the immense amounts of coal that would have to be burned to run the steam machines powering the dynamos. In the end we had a solar powered lander sending images back from Mars in 1997, using a couple wats.)