Caltech President Ray Jayawardhana studies planets beyond our solar system in the search for alien life. But he now faces ...

To support alien life, a planet doesn’t have to be exactly like Earth, but it does need a few key ingredients. First, it ...

Earth already contains organisms that survive conditions humans could never endure. Alien life, if it exists, may force ...

When it comes to the search for life elsewhere in the universe, methane and other chemical compounds are seen as signs of biology because they are often produced by living microbes. However, ...

Add Yahoo as a preferred source to see more of our stories on Google. An illustration of an exoplanet in an alien star system. New research suggests that radio emissions from intelligent aliens may be ...

Are we alone in the universe? Consider mysterious "extraterrestrial" radio signals. Unexplained gases on other planets. Things mistaken for UFOs. In the search for alien life, humans have been fooled ...

Scientists say moons around rogue planets wandering through the galaxy could remain warm enough for life thanks to tidal heating and hydrogen-rich atmospheres. These dark, starless worlds may have had ...

Hollywood makes initiating alien contact seem much easier than it has proven to be. In E.T. the Extraterrestrial, E.T. got stranded on earth when his alien compadres abandoned their botany mission. In ...