It starts with a signal. Faint, strange, and unlike anything humanity has ever recorded. Within hours, it escalates into an event that changes the course of history as an alien arrival on Earth ...

Earth is spinning faster than usual, with July 22 set to be one of the shortest days ever, just 1.34 milliseconds shy of a full 24 hours.

How hot can Earth get? Our planet’s climate history holds clues A tour through the planet’s past suggests the ways life will survive global warming — or not ...

Scientists agreed the rocky outcrops in a remote part of Quebec, Canada, were ancient. But were they really Earth’s oldest? New research suggests they are.

The planet’s rotation fluctuates as it travels around the sun, and measurements suggest we’re losing more than a millisecond during the long days of summer.

Scientists say they have identified Earth’s oldest rocks. It could reveal an unknown chapter in our planet’s history ...