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

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far ...

"If it's one or two Earth masses, which is still a pretty big planet, our inner Solar System would still remain quite nice," says Simpson. "We might experience slightly hotter summers or colder ...

The solar system consists of our star, the sun, and everything bound to it by gravity: the planets Mercury, Venus, Earth, ...

Earth" planet was discovered by researchers. It is not believed these planets are more common than previously thought.

For years, astronomers have been searching for a ninth planet in our solar system (after giving Pluto the old heave-ho and demoting it to a dwarf planet) and now researchers say they’ve found a ...

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 ...