Planet 9

An Artist's view of Planet 9

Planet Nine, also called Planet X, is a hypothetical planet orbiting beyond Neptune. This theory would explain the anomalies in the Kuiper Belt. Planet 9 could have a weight (mass) about 5 to 10 times the weight of Earth. Since this planet should orbit far away, it would take between 10000 to 20000 Earth years to orbit the Sun. The brightness (Magnitude) of Planet 9 could be around 21, which means that it is very dim.

Planet 9 Media

One hypothetical path through the sky of Planet Nine near aphelion crossing Orion west to east with about 2000 years of motion. It is derived from that employed in the artistic conception on Brown's blog.
Diagram illustrating the true anomaly, argument of periapsis, longitude of ascending node, and inclination of a celestial body.
The unusually closely spaced orbits of six of the most distant objects in the Kuiper Belt indicate the existence of a ninth planet whose gravity affects these movements.
The orbits of five of the objects with high-inclination orbits (nearly perpendicular to the ecliptic) are shown here as cyan ellipses with the hypothetical Planet Nine in orange.
A possible orbit of the 11-Jupiter-mass exoplanet HD 106906 b. Its orbit may share similarities with that of Planet Nine.

Related pages

References

https://science.nasa.gov/solar-system/planet-x/

Other websites

https://edition.cnn.com/2024/11/04/science/planet-nine-kuiper-belt-latest-evidence/index.html