Our solar system appears beautifully organized, but its stability is actually the result of an incredibly delicate cosmic ...

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 ...

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 ...

The interstellar comet 3I/ATLAS was the third object ever discovered in our solar system that originated from another star system. Despite a viral conspiracy theory, NASA officials have repeatedly ...