IAU Naming Conventions
The International Astronomical Union's structured system for naming solar system bodies — which embeds a deliberate mythology-astronomy mapping directly into planetary science. For trans-Neptunian objects especially, the naming rules constitute a systematic mythology encoding where orbital class determines mythological category.
This is the meta-framework that makes deliberate crossing notes (crossing-sedna, eris-dwarf-planet, and others) possible as a distinct category from accidental or observed crossings.
The Structured Mapping
| Object class | Naming convention | Examples |
|---|---|---|
| Classical KBOs | Creation/fertility deities from any mythology | Quaoar (Tongva), Haumea (Hawaiian), Makemake (Rapa Nui) |
| Plutinos (2:3 Neptune resonance) | Underworld deities | Orcus (Etruscan underworld), Ixion (Greek underworld figure) |
| Scattered disc objects | (similar to underworld/discord) | Eris (goddess of strife) |
| Centaurs (crossing giant planet orbits) | Centaur creatures from Greek myth | Chiron, Pholus, Nessus |
| Jupiter Trojans (L4) | Greek heroes from the Trojan War | Achilles, Odysseus, Agamemnon |
| Jupiter Trojans (L5) | Trojan heroes from the Trojan War | Priam, Hector, Aeneas |
| Neptune Trojans | Amazons | Otrera |
| Near-Earth objects | Mythological names (not creation/underworld) | Apollo, Eros, Hermes |
The logic: how far out an object orbits determines what kind of mythological figure it gets. The outer dark of the solar system → underworld and chthonic deities. The creative reservoir of the outer belt → creation deities. The dynamic boundary zone → liminal figures (centaurs, centaur creatures). The inner system → classical gods.
Why This Matters
The IAU system means that every time a new trans-Neptunian object is discovered and named, a deliberate mythological-astronomical correspondence is being created. The astronomers naming these objects are consciously selecting myths that resonate with the astronomical character of what they've found.
This is how sedna-dwarf-planet got Sedna (cold, dark, remote, ancient, controlling the deep), eris-dwarf-planet got Eris (her discovery caused strife), Haumea got a Hawaiian fertility goddess (she spins so fast she sheds moons — births them), and Orcus (an anti-Pluto with a nearly opposite orbit) got an Etruscan underworld deity.
General Rules
- Names must be pronounceable, preferably one word, max 16 characters
- Military/political leaders ineligible until 100 years after death
- Whimsical names acceptable for ordinary asteroids (26858 Misterrogers, 274301 Wikipedia)
- The discoverer proposes a name; the Working Group on Small Bodies Nomenclature (WGSBN) approves
- After IAU approval, published in the WGSBN Bulletin with a citation explaining its significance
Historical Development
The naming of planets with Greek/Roman mythology names predates the IAU — it was established practice by the time Uranus (1781) and Neptune (1846) were discovered. The asteroid belt initially used female names for main-belt objects, male for unusual orbits. As the population exploded (millions of numbered objects), the mythology-per-orbital-class system became necessary to impose semantic order.
The 2006 IAU vote that defined "dwarf planet" — triggered by Eris's discovery — also clarified the naming taxonomy by defining clear orbital categories, each with its corresponding mythological domain.