Planet-to-planet lightning...

Thread Starter

cmartinez

Joined Jan 17, 2007
8,218
Considering these two facts:
  1. 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.
  2. 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.
I have a couple of questions, and I'm not quite sure about their answers:
  1. Wouldn't by now one planet have different electric charge than the other?
  2. 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?
 

Papabravo

Joined Feb 24, 2006
21,159
I think the separation and recombination of electric charge is a dynamic and constantly changing process. Planets don't normally come close enough for us to witness such a discharge as you have hypothesized. It seems more likely that the conditions leading to an excess of ions in a part of the atmosphere would change as the planet rotates and recombination would occur. I can't imagine what would be required for a planet to accumulate an excess charge that could be sustained.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
8,218
I can't imagine what would be required for a planet to accumulate an excess charge that could be sustained.
Good points... I recently read that yet another theory of the way water formed in the solar system was through the bombardment of solar protons on oxygen-rich asteroids. A proton traveling with enough energy could split an O2 molecule and force itself on one of the atoms (a lone proton is, after all, a hydrogen ion), becoming OH, and since hydroxide is an unstable ion, almost immediately another proton would join it, forming the complete H2O molecule. Maybe all of the protons that make it to either planet end up participating in similar chemical reactions, thereby preventing any significant charge buildup ...
 

studiot

Joined Nov 9, 2007
4,998
A proton traveling with enough energy could split an O2 molecule and force itself on one of the atoms (a lone proton is, after all, a hydrogen ion), becoming OH, and since hydroxide is an unstable ion, almost immediately another proton would join it, forming the complete H2O molecule.
How does this proposed mechanism satisfy conservation of charge?

You lightning idea is interesting, however.
Although we don't know of any planetery encounters, close enough to sparkover, we have seen other bodies come close enough, but I don't know of any evidence of lightning as a result or otherwise.
Perhaps the Earth's atmosphere strips charge from meteors before sparkover can occur.
I don't know if there is evidence of lightning bombardment on astro body surfaces where there is little or no atmosphere.
I have always understood that lightning is an atmopheric phenomenon, witness the intense displays observed on Venus.
 
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#12

Joined Nov 30, 2010
18,224
I have wondered for decades, if you had really long test leads on your meter, what would the voltage be between the Earth and our moon? or the Earth and Mars?

I have not seen a satisfactory answer.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
8,218
I have not seen a satisfactory answer.
I don't remember it being reported that a discharge was triggered when any of the Apollo landers touched down on the moon. Mars would be a different case, since it has an atmosphere, maybe the probes reach potential equilibrium more gradually when they contact its atmosphere...
This is definitely a question for an astrophysisit or a planetary scientist...
 

Thread Starter

cmartinez

Joined Jan 17, 2007
8,218
Fox news?
This is not meant to be personal, but John Cleese about Fox News is to good to miss.
Well... yeah... I know Fox isn't the best fair-and-balanced reliable source of journalistic information out there... (although they do have interesting articles every once in a while, either scientific or some just plain nuts) but Fox was one of the hits when I googled the water-formation question...
 
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