Astronomers recently spotted a potential new dwarf planet beyond Pluto. This discovery, made in March 2023 using Japan’s Subaru Telescope in Hawaii, is named 2023 KQ14 and nicknamed Ammonite. The name comes from a long-extinct marine fossil, highlighting its link to a project called Formation of the Outer Solar System: An Icy Legacy (FOSSIL).
According to a study published in July in *Nature Astronomy*, Ammonite is classified as a “sednoid,” a term derived from another distant dwarf planet, Sedna, discovered in 2004. Sednoids are found beyond Neptune and have unusual orbits. Ammonite, for example, travels between 66 and 252 astronomical units (AU) from the sun, where 1 AU is the average distance from the Earth to the sun.
This find brings into question the long-debated Planet Nine hypothesis, proposed in 2016. This theory suggests there might be a Neptune-sized planet far beyond Neptune, influencing the orbits of some smaller Kuiper Belt objects. The existence of such a planet would explain the erratic paths of these celestial bodies. However, the orbit of Ammonite doesn’t align with that hypothesis. It strays onto a completely different path, decreasing the chances of a large planet existing in our solar system.
Study co-author Shiang-Yu Wang, an expert from the Institute of Astronomy and Astrophysics in Taiwan, explains that the Planet Nine hypothesis rests on the current known sednoids clustering on one side of the solar system. Ammonite’s orbit challenges this clustering idea.
Historically, the search for Planet Nine had gained traction due to oddities in the orbits of various celestial objects. Yet the recent findings suggest that our understanding may still be incomplete. In fact, the gravitational influences we see might stem from a variety of smaller bodies rather than a single, massive planet.
Experts like David Jewitt from UCLA emphasize that the evidence supporting Planet Nine has remained unclear and hasn’t strengthened over the years. Meanwhile, Christopher Impey from the University of Arizona believes that if Planet Nine does exist, it’s likely to be detected soon by the newly operational Vera C. Rubin Observatory in Chile, which is aimed at capturing extensive celestial data.
As we gain more insights, the cosmic puzzle deepens. While Ammonite’s discovery raises more questions than answers about our solar system’s structure, it also opens doors for future explorations and discoveries in the vast universe around us.
