The anomalous nature of the object led astrophysicist Avi Loeb to apply a thought experiment to it, highlighting everything about it that might align with a hypothetical alien spacecraft.

NASA is tracking a mysterious, fast-moving object entering our solar system, raising questions about whether it's just a ...

Our solar system's latest and only third known interstellar visitor is becoming more fascinating by the minute. Spotted in early July, the object, dubbed 3I/ATLAS, is believed to be a comet. It's ...

NPR's Ari Shapiro talks with astronomer David Jewitt about what we can learn from the third interstellar object to have entered our solar system, a comet-like object known as 3I/ATLAS.

Astronomers propose a new hypothetical planet, Planet Y, beyond Neptune, based on observed orbital anomalies in the Kuiper ...

Jupiter is our solar system's biggest planet by far. It used to be twice as large: Study A recent study found that Jupiter was once twice the size that it is now, making it big enough to swallow ...

Astronomers have discovered a brand new type of planet outside our solar system that, even in its infancy, is already bigger ...

So if our solar system is more or less flat in terms of the planetary rotations around the sun (I'm using typical pictorial depictions of the solar system), what is up and down from our solar ...

For astrobiologists, the search for life beyond our solar system could be likened to where one would look in a vast ...

When our Solar System first formed, we were made out of about 70% hydrogen and 28% helium, and only about 2% of everything else combined.