Solar System Surprise: Newly Found

A New Mysterious World Discovered

Scientists have found a new small object in our solar system, nicknamed “Ammonite.” It is about 380 kilometers wide and was spotted by the Subaru Telescope in Hawaii. Ammonite is considered a “fossil” that holds clues to the solar system’s early history.

It joins a rare group called sednoids—small bodies with unusual orbits far beyond the planets. As the scientists explain, this discovery “gives space scientists some answers to their questions—and more.”

Background on Sednoids and Sedna

The sednoid family began with the discovery of Sedna in 2003, a dwarf planet eight billion miles from Earth. Research suggests Sedna formed “at the early stage of [the solar system’s] evolution,” with its strange orbit shaped by forces in the Sun’s early crowded star cluster or close stellar encounters. Ammonite’s new presence expands knowledge of this distant region.

Tracking Ammonite’s Orbit

Ammonite was first detected in 2023, with earlier observations found in archives dating back nearly 20 years. This long-term data “significantly [improves] the accuracy of Ammonite’s orbit.” Unlike other sednoids, Ammonite’s orbit is different, showing that “the outer solar system is more diverse and complicated than previously imagined.”

Implications for Planet Nine and Solar System History

Dr. Yukun Huang, who modeled Ammonite’s orbit, noted: “The fact that Ammonite’s current orbit does not align with those of the other three sednoids lowers the likelihood of the Planet Nine hypothesis.” This suggests a planet might have existed long ago but was ejected. Dr. Fumi Yoshida added, “The presence of objects with elongated orbits and large perihelion distances in this area implies that something extraordinary occurred during the ancient era when Ammonite formed.” Understanding these distant objects is “crucial for comprehending the full history of the Solar System.”