Scientists don't call it the "Great Dying" for nothing. 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 ...

New research indicates that the water on Comet 67P/Churyumov–Gerasimenko has a molecular signature closely matching that of water found in Earth's oceans. This discovery revives the possibility that ...