What is ‘Ammonite’? - Rare object discovered beyond Neptune and the mystery of planet nine

Where ‘ammonite’ fits in the solar system (Image: File image of milky way galaxy, credit - AFP

A rare celestial object discovered beyond Neptune is surprising astronomers with its unusual motion. Named 2020 VN40, it orbits the Sun in 1,655 Earth years and appears to move in a synchronized pattern with Neptune.

First discovered in 2020, the object’s unusual movement adds to a growing list of recent findings beyond Neptune - including 2023 KQ14, nicknamed “Ammonite,” spotted just weeks earlier in the distant reaches past Neptune and Pluto.

Published in The Planetary Science Journal by the American Astronomical Society, the discovery supports the theory that Neptune’s gravity can capture and influence the orbits of objects drifting through the outer solar system.

“It shows that even very distant regions influenced by Neptune can contain objects, and it gives us new clues about how the solar system evolved” said  Rosemary Pike, lead researcher in Harvard & Smithsonian in Cambridge, Massachusetts.

Researchers believe this discovery could also offer deeper insight into the movement patterns of distant bodies in the solar system. “This new motion is like finding a hidden rhythm in a song we thought we knew. It could change how we think about the way distant objects move,” said Ruth Murray-Clay, co-author of the study from the University of California.

What is Ammonite and mystery of 'planet nine' 

A sednoid is an object beyond the orbit of NeptuA rare celestial object beyond Neptune, 2020 VN40, moves in sync with Neptune, offering new insights into the outer solar system and fueling the search for Planet Ninne that has a highly eccentric orbit, similar to that of the dwarf planet Sedna, one of the most distant objects in the solar system known to astronomers.

The newly discovered object “Ammonite,” found beyond Neptune and Pluto, could reshape astronomers’ understanding of the solar system’s past.

This is classified as an object which is similar to Sedna, a dwarf planet candidate in the outer solar system found in 2003. Ammonite orbits beyond Neptune and has a highly eccentric orbital path.

There has been a lot of attention among astronomers on Planet Nine in recent months. In May, scientists in Taiwan looking for a ninth planet in the solar system found hints in archive images. In June, a study by Rice University and the Planetary Science Institute put a number on the chances that a ninth planet exists - 40%.

Finding 'Ammonite'

It took nearly six years to discover and map the orbit of this object.

Astronomers from the Large Inclination Distant Objects survey found it while searching for unusual bodies in the outer solar system with orbits that extend far above and below the solar system’s plane.

The researchers utilized the Canada-France-Hawaii Telescope and Gemini North in Hawaii, along with Magellan Baade and Gemini South in Chile. So far, the LiDO survey has identified over 140 distant objects.

The Vera C. Rubin Observatory in Chile, which released its first impressive images in June, is anticipated to discover many more objects in the outer solar system.