Humanity would need five Earths to produce the resources needed if everyone lived as profligately as Americans, according to a report issued Tuesday.

vast ocean once covered a third of Mars, scientists believe. Such a stunning prospect greatly increases the chances of life having existed on the Red Planet, the fourth from the Sun in our solar system.

Patients facing blindness with a rare and incurable eye disease are expected to become the first ever people to benefit from an embryonic stem-cell therapy.

It may sound like a sci-fi vision, but Japan's space agency is dead serious: by 2030 it wants to collect solar power in space and zap it down to Earth, using laser beams or microwaves.

This is Part 6 in a 10-part LiveScience series on the origin, evolution and future of the human species and the mysteries that remain to be solved. We are currently the only human species alive, but as recently as maybe 24,000 years ago another one ....

The MESSENGER spacecraft's third flyby of the planet Mercury has given scientists, for the first time, an almost complete view of the planet's surface and revealed some dramatic changes in Mercury's comet-like tail.

The mystery of the origins of the Falklands Wolf described by Charles Darwin may finally have been solved.

Off the west coast of India, there is a suspicious basin called Shiva. It forms a rough ring over 500 kilometers (311 miles) in diameter and has a central underwater peak the size of Mt. McKinley.

In June 1833, Charles Darwin asked the captain of the HMS Beagle to delay his departure from Tierra del Fuego so that he could study a strange group of granite boulders he had found on the coast at Bahía San Sebastián.

Diverting sediment-rich water from the Mississippi River below New Orleans could generate new land in the river's delta in the next century.