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 ...

Scientists are sharpening the methods used to search for alien artifacts inside our own solar system, drawing on recent peer-reviewed studies published in The Publications of the Astronomy Society of ...

Billions of years ago, while the solar system was still young, a massive object may have drifted into it. It's not a spaceship, but it is an alien visitor in its own right—a colossal interstellar body ...