Research by Rice University Earth scientists suggests that virtually all of Earth's life-giving carbon could have come from a collision about 4.4 billion years ago between Earth and an embryonic planet similar to Mercury.
Scientists have found what they think is the oldest fossil on Earth, a remnant of life from 3.7 billion years ago when Earth's skies were orange and its oceans green.
An international research project has found human activity has been causing global warming for almost two centuries, proving human-induced climate change is not just a 20th century phenomenon.
Geologists have found the first evidence for China's Great Flood, a 4,000-year-old disaster on the Yellow River that led to birth of the Xia dynasty and modern Chinese civilization, researchers said Thursday.
A couple of times in four billion years, evolution has slowed to a crawl. And an eon or so has passed before more complex life forms, such as simple animals, could arise.