|MadSci Network: Astronomy|
If the mass of the ocean on each planet is not too big as compared to the mass of the planet, the presence of an ocean on the other planet does not make a big difference on a first approximation. This is the case of Earth, where the ocean mass is less than one thousandth of the Earth's mass. Tides are caused by the gravitational attraction of the whole mass of the other body. If one body has an ocean very small as compared to its total mass, it won't make a big difference on the other body tides. If the ocean mass must be taken into consideration on a second, more accurate approximation, the tides may vary in height depending on how each planet is rotating. Tides may be higher when the oceans on each planet are facing each other, but this would be noticeable only if the ocean has a sizable mass as compared to that of the planet. Vladimir Escalante Ramirez
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