It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

Scientists are intrigued after spotting a highly unusual celestial object lurking at the very edge of our solar system.

NASA's Perseverance rover is exploring a new Mars region called Krokodillen, which is thought to harbor some of the oldest and most intriguing rocks on the Red Planet.

Astronomers have discovered a new dwarf planet, named 2017 OF201, far beyond Pluto's orbit. It takes 25,000 years to orbit ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

The unusual orbit of a possible dwarf planet, known as 2017 OF201, makes it less likely that our solar system contains a ...