Imagine receiving a message from another world. Not from a distant galaxy millions of light years away, but from a planet ...

Proxima Centauri b is the closest known exoplanet that could be in the habitable zone of its star. Therefore, it has garnered a lot of attention, including several missions designed to visit it and ...

One million alien visitors from another star system could already be lurking in the solar system. We aren't talking about "little green men" here, however — more "little (and not so little) gray rocks ...