The United States led global production of rare earth elements (REEs) until the mid-1990s, when China emerged as the dominant supplier. China maintained near-total control of the market until 2012.

In order for a viable, sustainable economy based on human spaceflight to emerge in low Earth orbit (LEO), a number of elements must be present. First, the marketplace dynamics of supply and demand ...

Researchers have come across some evidence suggesting Earth had a ring system around 466 million years ago, which may have been a contributor to the global cooling event known as the Hirnantian ...

Earth's surface is a turbulent place. Mountains rise, continents merge and split, and earthquakes shake the ground. All of these processes result from plate tectonics, the movement of enormous chunks ...