Get the key points on this story in our 1-minute read.
- Meet 'Ammonite': A newly discovered sednoid – an icy, distant Solar System object nicknamed after its spiral fossil‑like orbit – officially called 2023 KQ14
- Only the fourth known of its kind: Sednoids are extremely rare. Ammonite joins Sedna, 2012 VP113 and Leleākūhonua in this exclusive group
- Exceptionally elongated orbit: It swings from ~66 AU (perihelion) to ~252 AU (aphelion) from the Sun, far beyond Neptune
- Mid-sized cosmic object: Estimated diameter is between 220–380 km, similar to about 40 times the height of Mount Everest
- 4.5-billion-year time capsule: Orbital simulations show it’s been stable since shortly after the Solar System formed
- Questions Planet Nine theory: Unlike other sednoids, its orbit is anti-aligned, reducing the argument for a distant Planet Nine shaping their paths
- Hints at early Solar System chaos: The orbital mismatch may point to events like a rogue star passage or vanished planet stirring things up about 4.2 billion years ago
- FOSSIL project success: Unearthed by the multi-national FOSSIL survey using the Subaru Telescope, plus archival data dating back to 2005, showing how wide‑field searches continue revealing ancient Solar System relics
Get all the facts about the discovery in our full news report on Ammonite 2023 KQ14
