Planet X, also called Planet Nine, is a hypothetical planetary body seven times the mass of Earth lurking behind Pluto. If ...

A few decades ago, the Solar System had nine planets, but in 2006 the International Astronomical Union reclassified Pluto as ...

Astronomers are searching for a potential ninth planet, known as Planet Nine, which could reshape our understanding of ...

Chiron is a class of comet-ish asteroids/asteroid-ish comets called centaurs – named after the half-human, half-horse hybrid ...

If Brown’s hidden world is real, Rubin will almost certainly find it or strong indirect evidence that it exists. “In the ...

As Earth completes yet another full orbit around the Sun, an encroaching storm is expected to bathe the planet in a glorious ...

Researchers have created a high-power tunable laser on silicon photonics, achieving nearly 2 watts using an LMA amplifier.

The Sun was a hive of activity on December 29-30, with multiple powerful flares and two coronal mass ejections (CMEs).

NASA Administrator Bill Nelson left a final decision on a new mission architecture to the next NASA administrator working ...