Considering these two facts:
- The earth has a magnetic field that is actively protecting us from the aggressive solar wind by continually forcing those particles (which are mostly free accelerated protons) to move away from us.
- Mars does not have a magnetic field to protect it, and it's speculated that that's the reason why its atmosphere is so thin, since those protons kept on hitting its molecules for billions of years, bouncing them off into outer space.
- Wouldn't by now one planet have different electric charge than the other?
- And if that were so, wouldn't a near-collision between the two unleash a monstrous electric discharge until both of their potentials have reached equilibrium?