What is the normal electrical charge of a celestial body?

Answer

What is a Celestial Body? Basically everything that revolves around the universe, and that includes elementary particles, such as protons and electrons, each with its own electrical charge. But most of the celestial bodies that matter, in the sense that we can see them from afar, are large accumulations of matter, containing both positive and negative charges. If we speak of ‘normal’, then the best approximation is that there are approximately equal amounts of each: the matter of which the celestial bodies are made usually starts from a neutral equilibrium with an equal amount of both, because the typical temperature in the universe is very low, and then most matter is in a neutral atomic or molecular state.

Take Earth now. It has a mass of about 6 x 10^24 kg. Each kilogram of matter contains of the order of 3 x 10^23 protons (positive charge) and electrons (negative charge). So in total about 2 x 10^48 of both. With a star like the Sun you have to multiply everything by three hundred thousand. If you then ask me whether there are now three or a hundred more electrons than protons on Earth, or vice versa, then I cannot answer that, because it has no measurable effect at all on the whole. And that’s why it doesn’t really matter. When we try to calculate the motion of celestial bodies relative to each other, we neglect the very small electrostatic effects that their residual charges may cause.

But this does not mean that electromagnetic effects have no meaning to describe phenomena in the universe. For example, if the excrement of a solar storm comes towards us, then the negatively charged electrons arrive first, and the positively charged protons only later: because of their smaller mass, electrons get a greater acceleration. When comets throw debris, positively or negatively charged particles also take on other orbits under the influence of the Sun’s magnetic field. These magnetic effects cause cometary orbits to deviate from pure planetary orbits that are determined solely by gravity. But even then it is a good assumption that the total charge of a comet is negligible.