A joint Japanese-European mission to Mercury just made its sixth flyby of the planet, revealing stunning close-ups of the ...

Stargazers will be treated to a dazzling six-planet "alignment" this January.

The solar system may hold a hidden surprise. Astronomers are investigating the possibility of a mysterious ninth planet, often referred to as Planet Nine. If found, this discovery could change the ...

Analyzing images from a nearby observatory ... and where we might finally find Planet 9. In studying the little worlds in the Kuiper Belt, we realized that their orbits are not in a random ...