@shoker
@Ravellon
The reason we see the moon behind Tatsumaki is for a scale of reference and for irony. The joke is lost when you explain it, so here I go killing again.
Psykos tried to attack Tatsumaki, trying to kill her. The result was a scalping of the planet which created tidal waves. Pretty scary stuff.
Saitama was blasted to the moon, then had to make a jump back to earth. When he did so, he left a permanent and visible crater on the moon which is so massively large it takes up roughly 1/8th of the entire surface of the moon. This wasn't an attack. This was him basically saying "oh whoops, guess I better get back to planet earth now." Like hopping back onto a bike.
Now with this massive power scale difference being shown to us, we see Tatsumaki asking where Psykos's energy comes from. She never asked that about Saitama. That's irony. That's why the moon was on the panel. It doesn't imply a connection between the moon and Psykos' power. It's just a way of reminding everyone who the top dog is and oh boy how funny it is that Saitama is way stronger than people can comprehend and they're focusing on things much less important.
See how not funny it is now? You're welcome?