Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner ...

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

What just happened? A newly identified object spotted in two infrared sky surveys may be the most substantial evidence for the elusive Planet Nine – a potential Neptune-sized world orbiting ...

Over millions of years, these objects grew larger, sweeping up material in their orbits and becoming the planets we know today. This model of solar system formation is known as the nebular hypothesis.

TIM:When I was up on the ISS, that different perspective really brought home the sheer scale of the ... it's a little mechanical model of our solar system. You can see the planets here, orbiting ...

Astronomers searching for a ninth planet in our solar system say they've found a "good" candidate far beyond Neptune, ...

For nearly a decade, scientists have been on the hunt for Planet Nine – a hypothetical celestial object on the edge of our Solar System. Now, astronomers claim to have discovered this ninth ...

Astronomers claim to have discovered a new ninth planet in our Solar System. Planet Nine, also known as Planet X, is a hypothetical celestial object that would distantly orbit our Sun – but ...