New evidence found for the existence of the Ninth planet

Astronomers presented compelling arguments in favor of a hypothetical celestial body beyond Neptune's orbit

On July 16, 2025, an international group of astronomers from the California Institute of Technology (Caltech) and the Maunakea Observatory in Hawaii released exciting new data that substantially strengthens the hypothesis about the existence of the so-called Planet Nine - a mysterious massive object presumably hiding at the distant frontiers of the Solar System.

By Planet Nine, scientists mean a hypothetical celestial body whose mass, according to calculations, is 5-10 times greater than Earth's, and whose orbit lies 10-20 times farther from the Sun than Pluto's path. The bold hypothesis about its existence was first proposed by astronomers Konstantin Batygin and Michael Brown in 2016, based on careful analysis of unusual anomalies in the movement of trans-Neptunian objects (TNOs).

In the new scientific paper, published on July 15, 2025, in the prestigious journal The Astronomical Journal, researchers presented the results of detailed analysis of the orbits of more than 20 TNOs, located at a colossal distance of over 250 astronomical units (AU) from the Sun. These distant cosmic bodies demonstrate unexplainable synchronization in orbital parameters, which, according to scientists, with high probability indicates the gravitational influence of a massive and still undetected object.

To collect unique data, the capabilities of the powerful Subaru telescope, located at the summit of Mauna Kea, were used, as well as archival images obtained as part of the large-scale Pan-STARRS survey. Additionally, complex computational simulations were applied, modeling the influence of the hypothetical planet on the dynamics of distant bodies over millions of years.

Professor Konstantin Batygin noted:

"We are not claiming that we have found Planet Nine, but the probability that the detected anomalies are caused by a random distribution of objects is now less than 0.4%. This is a serious reason to continue the search."

His colleague Michael Brown added that new observations allow narrowing down the presumed search area:

"We assume that the planet is located in a sector of the celestial sphere distant from the center of the Milky Way, which makes its visual detection difficult, but not impossible."

Astronomers plan to continue exciting observations in 2025-2026, using the revolutionary Large Synoptic Survey Telescope (LSST) in Chile, which is scheduled to launch at the end of this year. Its unprecedented sensitivity and frequency of surveys will significantly increase the chances of directly detecting the mysterious Planet Nine or its indirect trace.

If the existence of the planet is confirmed, it will be the most significant discovery in the Solar System in recent decades, comparable in historical significance to the discovery of Pluto in 1930 and its subsequent reclassification as a dwarf planet in 2006.

Context:
The current classification of Solar System planets includes eight official planets. Planet Nine, if it exists, could explain a number of anomalies in the distribution of TNOs and shed light on the formation processes of the outer Solar System.