I understand there are normal phases where the moon is partially covered by the Earth’s shadow, how can it be completely covered one night and full the nights before and after? What happens during an eclipse where the moon can go through all the phases in a few hours, and then go back to full tonight and normal decreasing/increasing phases each night?
In: 17
An eclipse will always happen at the full moon, because that’s when the sun and moon are on opposite sides of the earth, meaning that we see the fully illuminated side (full moon). Similarly a solar eclipse (moon passing between sun and earth) will always happen at anew moon.
The only reason lunar eclipses don’t happen at every full moon is that earth’s shadow is not that big, so the angles have to be just right in order for the moon to pass through it.
Edit: I should add that normal moon phases have nothing to do with earth’s shadow, but with the relative angle of the earth-moon-sun system, which changes how much of the illuminated side of the moon we can see. Eclipses are the only time when our shadow falls on the moon.
Latest Answers