Just the third-ever confirmed interstellar object has been detected in our solar system. Here's what we know. (Spoiler: It's ...

The size of the Solar System and the Universe is truly beyond our comprehension. When we think of the vastness of space, we ...

What if there’s a planet hiding in our solar system, 10 times larger than Earth? While this theory has yet to be confirmed, ...

Pluto is 100 miles smaller than the smallest planet but is not a major planet. Here's which planet in our solar system takes the title instead.

How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between ...

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 ...

A fascinating glimpse into how a solar system like our own is born has been revealed with the detection of planet-forming ...

Astronomers have spotted centimeter-sized “pebbles” swirling around two infant stars 450 light-years away, revealing the raw ...

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, researchers say.

Learn about the recently discovered trans-Neptunian object that may eventually join Pluto as a dwarf planet, found at the edge of our solar system.

Astronomers have discovered that the Jupiter, the largest planet in our Solar System, was once so big that it could have held 2,000 Earths.

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact.