This phenomenon happens twice a year. When equinoxes happen, a terminator, also known as the twilight zone, is seen as a dividing line between the light and dark parts of the Earth directly through the North and South Poles. Besides the Earth, every other planet in the solar system ...
Every six months, the equinox splits Earth's day almost in half. Here's how it happens—and why people have celebrated it since ancient times.
The March equinox would occur on the same day every year if the Earth took exactly 365 days to make a complete revolution around the Sun. But this is not the case. It takes the Earth about 365.25 days on average to go around the Sun once. The Gregorian Calendar accounts for this by ...