While much of the U.S. sees its hottest day in late July, some coastal cities like San Francisco don’t peak until fall. A ...

Scientists break down the reasons why days are getting shorter—and the mystery they're still trying to solve about Earth's ...

Is the Earth spinning faster? Is July 22 the shortest day ever? Here's what to know about the Earth's rotation and why is today the shortest day.

Zotov predicts Earth’s rotation may soon decelerate once again. If he’s right, this sudden speeding-up could prove to be just a temporary anomaly in the planet’s long-term trend toward slower rotation ...

Look west at sunset to find the razor-thin crescent moon hanging less than 10 degrees above the horizon. Regulus will appear ...

Two days this summer have been unusually short, with the shortest expected on Aug. 5, leading global timekeepers to consider ...