The Silurian Hypothesis asks whether signs of truly ancient past civilizations would even be recognisable today.

Humans dominate Earth today, building cities, launching spacecraft and transforming the planet in ways no other known species ever has. But what if we were not the first civilization to reach this ...

It is no secret that humans are the dominant species on Earth. And with no confirmed evidence of intelligent life elsewhere in the universe, we often assume we are also the most advanced civilization ...

Add Yahoo as a preferred source to see more of our stories on Google. The fossilized tail bones of an Ichthyosaurus, around 190 million years old and weighing 800 kilograms. - Markus Scholz/picture ...

(CNN) — When astrobiologist Adam Frank walked into the office of NASA scientist Gavin Schmidt, he had what he believed was the weirdest question: do aliens experience climate change? It took just ...