Astronomers have discovered a new icy object beyond Pluto, nicknamed 'Ammonite' (officially 2023 KQ14), which challenges current understanding of the Solar System's history.

Observations of 2023 KQ14 were conducted in March, May, and August 2023, with follow-up work in July 2024 to track its orbit over nearly two decades.

2023 KQ14 is classified as a 'sednoid,' a rare category that includes only three other known objects, making it the fourth of its kind.

This discovery was made using the Subaru Telescope as part of the FOSSIL project, which aims to explore the formation of the outer Solar System and study its icy remnants.

Numerical simulations suggest that Ammonite has maintained a stable orbit for about 4.5 billion years, indicating a complex and diverse outer Solar System.

Dr. Fumi Yoshida emphasizes that the discovery of Ammonite in a remote area with minimal gravitational influence from Neptune points to significant events during its formation.

The unique trajectory of Ammonite decreases the likelihood of the existence of Planet Nine, implying it may have been ejected from the Solar System, which suggests a more complex outer structure.

Current orbit data from 2023 KQ14 lowers the probability of Planet Nine's existence, hinting at a past ejection of a planet from the Solar System.

Studying objects like 2023 KQ14 is crucial for understanding the Solar System's history and the unusual events that occurred during its formation, according to Dr. Yoshida.

The differing orbit of Ammonite compared to other sednoids raises questions about the position and existence of Planet Nine, suggesting it may need to be farther out than previously thought.