Solar system boundary artifact unearthed solves Planet Nine enigma
In a groundbreaking discovery, astronomers have uncovered a new space relic named Ammonite, a distant, icy body with a highly elongated orbit that dances around the outermost fringes of our cosmic neighbourhood. This discovery, made possible by the FOSSIL project, has significant implications for our understanding of the early Solar System's dynamics and the long-standing 'Planet Nine' hypothesis.
Ammonite's orbit is distinct and does not align with the clustered orbits of the other three known sednoids. This misalignment poses a challenge to the 'Planet Nine' hypothesis, which primarily relies on the gravitational influence of a distant, massive planet to explain the clustering of sednoid orbits. The divergent orbit of Ammonite suggests that either Planet Nine might not exist or that it must have a different orbit or influence than previously thought.
Some scientists propose a scenario where Planet Nine once existed but was later ejected from the Solar System. This ancient planet could have sculpted the outer Solar System early on, launching objects like Ammonite into their unusual orbits before disappearing. This idea is supported by simulations showing that giant planets could be scattered and escape the Sun’s gravity in the early Solar System.
Alternatively, other explanations, such as gravitational effects from a passing star or other historic cosmic events, might be responsible for shaping the orbits of distant objects like Ammonite and the other sednoids.
The discovery of Ammonite provides a new "fossil" object, a relic from billions of years ago, which can help trace the Solar System's formative events and its outer structure. Ammonite's presence requires solar system formation theories to account for not only the clustered sednoids but also this orbital outlier, deepening researchers' understanding of the complex gravitational interactions in the early Solar System.
This advances our ability to probe the deep outer Solar System and demonstrates that current observational surveys can "plumb the Solar System's depths," helping to uncover more about its history and arrangement. The FOSSIL project, led by an international team primarily from Japan and Taiwan, is far from finished, and telescopes like the Subaru Telescope in Hawaii are continuing to peer into the deep dark, hoping to uncover more secrets about our Solar System's past.
The newly discovered space rock, Ammonite (officially 2023 KQ14), is the fourth known sednoid. Its extreme orbit and its status as a Solar System fossil make it special. The presence of objects with elongated orbits and large perihelion distances in the outer Solar System implies something extraordinary occurred during the ancient era when Ammonite formed. Ammonite offers clues about how the planets formed around the Sun and whether a mysterious ninth planet still lurks in the darkness.
More discoveries like Ammonite could help us piece together the full story of our Solar System's formation and evolution. The full paper on Ammonite's discovery can be read at [www.nature.com/articles/s41550-025-02595-7](http://www.nature.com/articles/s41550-025-02595-7).
- The peculiar orbit of Ammonite, a newly discovered space relic, challenges the 'Planet Nine' hypothesis in astronomy, as it does not align with the clustered orbits of the other sednoids, making it an intriguing Solar System fossil.
- The findings from the FOSSIL project, including the discovery of Ammonite, have significant implications not just for the early dynamics of our Solar System but also for the health-and-wellness of our understanding of the universe, as they deepen our knowledge of the complex gravitational interactions in space-and-astronomy.
- As telescopes continue to peer into the depths of space, such as the Subaru Telescope in Hawaii, the hope is that more discoveries like Ammonité will be made, helping us to piece together the full story of our Solar System's formation and evolution, thereby enriching our grasp of the universe's mysteries.
