The Mechanics of Earth's Spin Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 ...

A strange shift in Earth's rotation is making our days milliseconds shorter — and scientists are racing to understand why. The days are getting shorter and not just because summer is waning in the ...

Day and night will get equal time for a brief moment Monday as much of the world heads into fall. The autumnal equinox arrives Monday, marking the start of the fall season for the Northern Hemisphere ...