The Earth: a ringed planet, much like Saturn, surrounded by a hula hoop of asteroids. The summit of Mount Everest: a tropical ...

"Over millions of years, material from this ring gradually fell to Earth, creating the spike in meteorite impacts," said ...

In the past 500 million years on Earth, there have been five mass extinctions. Here are a few incredible species that managed ...

A huge 75-foot-tall square boulder deep in Wyoming’s Bighorn Mountains has been baffling people since it was discovered.