The most crowded alien planetary system found yet possesses five worlds all orbiting a star at least 12 times closer than Earth does the sun, researchers say. Investigators discovered these exoplanets ...

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 ...

What would happen if we discovered alien life right here in our solar system? From the icy oceans of Europa to the methane ...

Harvard’s UFO-hunting astronomer Avi Loeb says interstellar object 3I/ATLAS still has strange, unresolved clues - from its near-perfect planetary-plane path to odd jets ...

If life exists elsewhere, it might not be on worlds like Earth. Here are some of the more peculiar places scientists are looking.

There may be 19 asteroids in orbit around the sun that come from somewhere else entirely. If true, we could visit an alien 'world' without ever leaving the confines of the solar system. Share on ...

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 ...

3I/ATLAS, a mysterious interstellar object racing toward the Sun, is baffling scientists with its speed and origin. Some researchers suggest it could even be alien-made, drawing comparisons to probes ...

There’s a visitor in town, and its name is 3I/ATLAS. The presumed interstellar comet presents a rare opportunity for astronomers to study an object born a long time ago in a star system far, far away.

A Harvard astronomer is making waves by suggesting that a massive interstellar object hurtling through our solar system might be an alien spacecraft.