About 700 million years ago, enormous glaciers flowed across the Earth's surface in powerful frozen ... all of which may have contributed to the early development of life, the University of ...

K. Cloud feedback: A stabilizing effect for the early Earth? Science 217, 1247–1247 (1982). Sagan, C. & Mullen, G. Earth and Mars – Evolution of atmospheres and surface temperatures.

Beneath the surface of our planet, at a depth of about 2,900 kilometres, lie enigmatic objects. These extraordinary formations are located at opposite ends of the Earth: one under the region of ...

While you can find dozens, if not hundreds, of images of Mars’ surface, Earth’s other neighbor, Venus, is limited to a series of images taken in the early 1980s. Further, those images weren ...

Estimates for surface temperatures 3.5 billion years ... small concentrations of the greenhouse gas ammonia could have warmed the early Earth. But the gas readily breaks down into the greenhouse ...