Pluto's days, though they drag on a bit at around 153 hours, are nothing compared to its years. Pluto's orbit takes 248 Earth ...

Perihelion is the point at which an orbiting body is closest to the sun. The word comes from Greek and literally means around ...

A “natural history” approach to space exploration would take into account instead developments in the fields of physics, ...

"We're not saying, and we can't say, that there's no life in Europa. What we're saying is that it's a harder proposition, ...

NASA has finally peered into the heart of a white dwarf system in a way astronomers have been chasing for decades, turning a ...

Which way is ‘down’ has a different answer depending on where you are on Earth, in the solar system, in our galaxy and beyond ...

Discovered by volunteer scientists, this alien planet is out of synch with its siblings ...

The space rock, known as "2026 AJ" and 40 feet in diameter, is hurtling toward our planet at around 20,500 miles per hour.

Exoplanets like Earth have been discovered but not all Earth-like planets are equal when it comes to alien life.

Scientists have discovered more than 6,000 planets beyond our solar system. What if some of them aren't planets at all, but ...