Same as the Earth, 1 Astronomical Unit or 149.6 million kilometers.
The earth is about 384,392 km away from the moon.
The moon is far away because if it were to close then the gravity from earth would pull it in to use amd destroy the earth. And the moons graviy pull that it has on earth already affects the ocean,...
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Depends on the speed. At the speed of light, it takes a little over a second.