A few years ago Venus was measured to be at a surprisingly large electric potential of $\Phi_{Venus}=+10.6$ volts, which may be one of the reasons Venus lost its water. Does this mean that Venus has a net positive electric charge of $$Q_{Venus} \approx 4\pi\epsilon_0 R_{Venus} \Phi_{Venus} = 0.007\mathrm{C}$$ There was a recent NASA mission to measure the Earth's electric potential, thought to be only $\sim +0.3$ V, but I can't find any published results yet.

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    $\begingroup$ Excellent question! Different but somewhat related in Astronomy SE What are the experimental limits to the residual charge of the Sun? The very thorough answer there mentions only 77 Coulombs for the Sun (theoretical) and that such a charge would be very difficult to try to measure experimentally. Total charge may be difficult to define, one needs to draw an arbitrary boundary around the body, and the charge coming and going through that will vary with time and solar activity. There's variable moving charges everywhere in the solar system... $\endgroup$
    – uhoh
    Commented Mar 13, 2023 at 1:22
  • $\begingroup$ ...especially near the Sun. $\endgroup$
    – uhoh
    Commented Mar 13, 2023 at 1:23


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