There’s a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic ...

A recent study found that Jupiter was once twice the size that it is now, making it big enough to swallow up 2,000 Earths.

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

Scientists hunting for the hypothetical Planet Nine have discovered a potential new dwarf planet, 2017 OF201, in the outer ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

NASA's Juno mission finds a massive lava lake in Jupiter, offering new insights into volcanic activity beyond Earth and the ...

For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, ...

Scientists hunting for Planet Nine, an elusive planetary body that could change our understanding of the solar system, have ...

Christopher Palma does not work for ... the first thing to form in our solar system. This happened about 4½ billion years ago. Then the planets began to emerge, as the billions of particles ...

In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

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 ...