Earth has quietly picked up a new traveling companion, a tiny captured object that astronomers say will loop around our planet for decades before slipping back into deep space. NASA and independent ...

Humanity has been leaking radio noise into the cosmos for just over a century, and those signals now form a vast, expanding shell around our planet. That invisible sphere, often called Earth’s radio ...

Several studies have predicted that not all geomagnetic reversals have been discovered, but it was unknown in which periods they might be hidden. Researchers led by the National Institute of Polar ...