A new paper by physicist Edward Witten proposes hunting Planet 9 using a fleet of laser-launched probes like Breakthrough Starshots'.

Astronomers discover a new strategy for detecting exoplanets: look for aligned binary stars that reveal hidden worlds more ...

Planet 9 likely isn't a stolen exoplanet after all. New research shows the probability of ideal planet-swapping positions between young stars is near zero.

There are hundreds of planets on Lucasfilm's official map of the galaxy far, far away, including lots you've heard of and many you haven't.

ASTRONOMERS say they’re zeroing in on an elusive NINTH planet in the outer reaches of our Solar System. In a recent study, experts ruled out a section of the night sky where the mysterious ob… ...

Almost a decade after astronomers proposed the existence of Planet 9, an unseen extra planet in the distant reaches of the solar system, they still haven’t all agreed whether it’s real or not.

Search for Pluto's possible space replacement, 'Planet 9,' is heating up as astronomers search the skies beyond Mars and Neptune ...

After a decade-long search, some scientists say a growing number of clues point to the existence of a hidden planet in the Kuiper Belt beyond Neptune — and they may soon have the opportunity to ...

3D map of exoplanet atmosphere shows wacky climate "This planet’s atmosphere behaves in ways that challenge our understanding of how weather works." ...

The implications were dramatic: with Planet Nine in tow, 2017 OF201 is thrown out of the solar system within 100 million years, an eyeblink on cosmic time.