Why two astronomers think we have a ninth planet

There are quirks at the far edge of our solar system, in the form of disturbed objects in the Kuiper belt. One explanation: Planet Nine.

New evidence suggests a ninth planet lurking at the edge of the

Hubble spots distant exoplanet similar to potential 'Planet Nine

Hunt for ninth planet reveals new extremely distant solar system

Lighting a path to Planet Nine

Planet Nine ruled out as the cause of outer solar system 'mystery

Far beyond Pluto, a possible Planet Nine awaits discovery

Is Planet Nine an undiscovered world?

Why are Astronomers Unable to Locate The Colossal Planet X?

New Earth-Like Planet Hiding in Outer Solar System, Astronomers