The Moon, our constant celestial companion, is drifting away from Earth at a slow but measurable rate. According to a ...

Because the Earth is doing the work of increasing the Moon's momentum, the Earth's rotation slows down in turn, as its momentum goes to the Moon. To put it another way, as the Moon's orbital momentum ...

Long ago, the Moon was much nearer Earth. Scientists believe a protoplanet collision created the Moon 4.5 billion years ago.

Ever since its formation around 4.5 billion years ago, Earth's rotation has been gradually slowing down, and its days have ...

Because oxygen seeps (diffuses) out of mats slowly, the timing of sunlight becomes a big deal. Short days mean the sun sets ...

WASHINGTON — Wednesday will be slightly shorter than usual, but you probably won't notice the difference even if you're watching the clock closely. Earth is expected to complete a full rotation on ...