The newcomer replacing Pluto presently goes by “Planet Nine.” If and when it finally shows up, it will get the honor of a real name, but so far, the evidence for this hypothetical planet is all ...

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

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

Astronomers believe that our solar system may still hold surprises, with ongoing efforts to find a hidden ninth planet, often referred to as Planet Nine or Planet X. If confirmed, this discovery ...

Six of our cosmic neighbors are expected to line up across the night sky tonight, in what has been dubbed a "planetary parade ...

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

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

A six-planet alignment or parade will form an arc in the early night sky, peaking in it's visibility Jan. 17-18. We let you ...

However, while no such events took place on that date, nor on his revised date of Dec. 25, 1919, the seeds of anxiety and ...