Astronomers have discovered an incredibly rare non-planetary body lurking on the outer reaches of the Solar System, which could shake up scientists’ understanding of our little corner of the universe and shed more light on the possibility of the mysterious Planet Nine.
“Understanding the orbital evolution and physical properties of these unique, distant objects is crucial for comprehending the full history of the Solar System,” Yukun Huang of the National Astronomical Observatory of Japan, said in a press release.
For now, the object goes by the not-so-catchy name of 2023 KQ14 and the nickname “Ammonite,” but astronomers promise a more classical name is in the works.
Planets and Asteroids and Sednoids
The celestial object is a sednoid — and is only the fourth of its kind known to science. Sednoids are a type of Trans-Neptunian object located beyond Neptune in the outermost region of the Solar System. They are particularly interesting because they share notably different orbital characteristics from other bodies at equivalent distances from the sun.
For one, they exhibit particularly high perihelia, which basically means that even at their closest approach to the sun, they retain a vast distance from the star. They also maintain a significant distance from any of the planets in the Solar System.
“These objects are challenging to observe, and thus their detections are still rare, yet they play a crucial role in constraining models of Solar System formation,” the study’s authors wrote.
Ammonite is markedly different from its compatriots — its orbit does not line up with the other three, and its position in the Solar System fills a gap (the q-gap) in the distribution of distant objects. This has two major implications, the researchers say. First, it suggests the Solar System is even more complex than we might assume. The second is that the orbit of a Planet Nine — if it exists in the first place — would need to be further from the sun than previously thought.
“The fact that 2023 KQ14’s current orbit does not align with those of the other three sednoids lowers the likelihood of the Planet Nine hypothesis,” said Huang in a press release. “It is possible that a planet once existed in the Solar System but was later ejected, causing the unusual orbits we see today.”
Read More: New Telescope Could Potentially Identify Planet X
What Else Do We Know About Ammonite?
Observations and numerical simulations suggest Ammonite has sustained a stable orbit for 4.5 billion years or more, and while it may differ from its fellow sednoids today, it appears likely their orbits were similar 4.2 billion years ago.
Researchers also note that Ammonite has a particularly high perihelion of 66 au (Astronomical Unit), which, to put it into perspective, is equivalent to 66 times the average distance between Earth and the sun. That, the researchers say, makes it the third-largest perihelion of objects listed in the International Astronomical Union Minor Planet Center with a semi-major axis (or mean distance from the sun) greater than 200 au.
Formation of the Outer Solar System
The Subaru telescope first detected Ammonite in 2023 as part of the survey project FOSSIL, an acronym that stands for Formation of the Outer Solar System: An Icy Legacy. Additional observations in 2024 were able to track the sednoid’s orbit over 19 years.
“At present, the Subaru Telescope is among the few telescopes on Earth capable of making such discoveries,” said Huang in a press release. Discussing the finding, he said: “The presence of objects with elongated orbits and large perihelion distances in this area implies that something extraordinary occurred during the ancient era when 2023 KQ14 formed.”
Read More: Chaos in Our Solar System Could’ve Caused Planet X’s Theoretically Wide Orbit
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Nature Astronomy. Discovery and dynamics of a Sedna-like object with a perihelion of 66 au
Rosie McCall is a freelance writer living in London. She has covered science and health topics for publications, including IFLScience, Newsweek, and Health.
