Large Trans-Neptunian Object Discovered

05/22/2025 Astronomy

Astronomers have recently added a significant new member to the catalog of trans-Neptunian objects (TNOs). Designated 2017 OF201, this minor planet is notable for its impressive size and remarkably distant orbit.

With an estimated diameter between 290 and 510 miles, 2017 OF201 rivals Ceres, the largest asteroid in the asteroid belt, in size. Its classification as a TNO reflects its location beyond Neptune's orbit, already a considerable distance from the Sun.

An Extreme Trans-Neptunian Object

However, 2017 OF201 stands out even among TNOs. Its highly eccentric orbit carries it as far as 838 astronomical units (AU) from the Sun—a distance nearly 30 times greater than Neptune’s average distance. This extreme orbit earns it the designation of an extreme trans-Neptunian object (ETNO).

The discovery of such an object fuels ongoing speculation about the potential existence of Planet Nine, a hypothetical planet far beyond Neptune whose gravity might explain the unusual clustering of objects in the Kuiper Belt. While 2017 OF201 is not Planet Nine, its existence adds another piece to the puzzle, and further highlights the mysteries surrounding the outer reaches of our solar system.

Further research into 2017 OF201 and similar objects could provide valuable insights into the formation and evolution of our solar system. The continued discovery of these distant bodies underscores the vastness and complexity of the space around us, and the many secrets it still holds.