Satellite image of the Earth with the Atlantic Ocean in the centre. From space, the Earth looks like a sphere or a ball. About two thirds of the surface is covered with water, and the rest is ...

About 252 million years ago, upward of 80% of all marine species vanished during the end-Permian mass extinction—the most extreme event of its kind in Earth's history ... quantitative predictions of ...

It was the first human spaceflight to circle the globe above the poles and the first Pacific splashdown for a space crew in ...