The placement and orbits of small, so - called extreme trans - Neptunian objects, can help narrow down the size and distance from the Sun of
the predicted ninth planet, because that planet's gravity influences the movements of the smaller objects that are far beyond Neptune.
Not exact matches
Last year, Mike Brown and Konstantin Batygin at the California Institute of Technology used this idea to
predict the existence of a
ninth planet, thought to be 10 times the mass of Earth, orbiting around 700 AU from the sun.
The more objects that are found at extreme distances, the better the chance of constraining the location of the
ninth planet that Sheppard and Trujillo first
predicted to exist far beyond Pluto (itself no longer classified as a
planet) in 2014.