Astronomers propose a new hypothetical planet, Planet Y, beyond Neptune, based on observed orbital anomalies in the Kuiper ...

For years, astronomers have searched the outer reaches of our solar system for Planet 9, a theoretical planet that could ...

A new study suggests the existence of Planet Y. This hidden planet may be affecting the Kuiper Belt. The gravity of Planet Y could be causing a tilt in the orbits of some icy objects. Researchers ...

New discoveries of objects in the Kuiper Belt have also presented challenges for the Planet Nine theory. The latest is known ...

Another mystery is how Planet Nine, if it is real, ended up on an orbit that potentially brings it as close as 280 AU and as distant as 1,120 AU, which is far beyond the realm of the other planets.

Astronomers have picked up evidence of an Earth-sized world, distinct from the previously hypothesised Planet Nine and Planet ...

If Planet 9 is real, this observatory has around a 70 to 80 percent chance of finding it, he estimates, adding that it's not a sure thing because there are so many uncertainties.

Astronomers have a potential Planet Nine candidate, detected via infrared radiation. This candidate's orbit is very different from what's predicted for Planet Nine. The candidate may be a false ...

A newly discovered dwarf planet called 'Ammonite' (2023 KQ14) has been spotted in the outer solar system, and it could be another nail in the coffin for the Planet Nine hypothesis.

Planet Nine should be detectable by that telescope. But it would require an adjustment in the planned observing protocol to extend the telescope’s survey farther north than planned, Brown says ...