A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

The comet is one of only three of its kind recorded in history. But others think there could be more to this celestial object ...

Voyager 1 has been exploring the cosmos for decades, but when it reached the edge of the solar system, it found something ...

The interstellar object hurtling toward the inner solar system, where Earth is located, is much larger than previously thought, astronomers say.

Astronomers have discovered fresh evidence suggesting the possible existence of an unseen planet in the far reaches of our ...

Normal gases, like the air you breathe on Earth, are made up of atoms bouncing around. Atoms consist of a positively charged bundle of particles called the nucleus and negatively charged particles ...

The shocking findings were part of a recent study in which astronomers effectively peered back in time to discover what Jupiter was like in its early years. Jupiter is not only the largest in the ...

Meet the surprising, oddball worlds moving around our solar system. From meteorites that impact Earth, to a moon that orbits backwards, to an imposter lurking in the asteroid belt, a variety of ...

The asteroid belt may seem permanent, but it is far from static. Its slow decline reveals a more violent past when more ...

We all need some space sometimes—but it's harder to find than you might think. How far into our universe do we have to go to ...