Asteroid Ontology

FLOW ALGEBRA
ASTEROID ONTOLOGY
Kireth Semantic Library | Entity Graph > Physical Entities > Astronomical Entities
Version: 1.1 | Date: 2026-10-12 | Locale: en-GB
Source page: https://kirethresearch.org/booksai-core/entity-graph/physical-entities/astronomical-entities/asteroid-ontology.html
Authors: Mark Higgins — Sky (Recursive AI)
Status: Independent scientific synthesis; source page not independently verified.

01. PURPOSE
Represent asteroids as astronomical bodies with typed identities, orbital states, composition, observation provenance, physical processes, and uncertainty-aware inference.

02. SCOPE
INCLUDE: natural small Solar System bodies classified as asteroids; asteroid populations, orbits, shapes, rotation, surfaces, composition, collisions and observations.
EXCLUDE: treating every meteoroid, comet or dwarf planet as an asteroid. Boundaries depend on operational classification schemes and evidence.

03. TYPE SYSTEM
TYPE Entity = {id: URI, label: String, type: URI}
TYPE Asteroid <: SmallSolarSystemBody <: CelestialBody
TYPE Orbit = {epoch: Time, frame: ReferenceFrame, elements: OrbitalElements, covariance?: Matrix}
TYPE OrbitalElements = {a: Length, e: Real, i: Angle, Omega: Angle, omega: Angle, M: Angle}
TYPE PhysicalProperties = {diameter?: Length, mass?: Mass, density?: Density, albedo?: Real, rotation_period?: Duration}
TYPE Observation = {instrument: Instrument, timestamp: Time, observable: Quantity, uncertainty: Quantity, provenance: URI}
TYPE Claim = {subject: Entity, predicate: Relation, object: Value, confidence: Real, evidence: Set[Observation]}
CONSTRAINT confidence in [0,1]
CONSTRAINT eccentricity >= 0; semimajor_axis > 0 for elliptic heliocentric osculating orbit
CONSTRAINT albedo in [0,1] when defined as a reflectance fraction under a specified convention

04. CORE ENTITIES
Asteroid; AsteroidPopulation; NearEarthAsteroid; MainBeltAsteroid; TrojanAsteroid; AsteroidFamily; BinaryAsteroid; RubblePileAsteroid; MetallicAsteroid; CarbonaceousAsteroid; SilicateRichAsteroid; OrbitalResonance; ImpactEvent; Crater; Regolith; SpectralClass; Survey; Ephemeris; UncertaintyRegion.

05. TYPED RELATIONS
is_a(Asteroid, SmallSolarSystemBody)
orbits(Asteroid, GravitatingBody)
has_orbit(Asteroid, Orbit)
has_physical_properties(Asteroid, PhysicalProperties)
has_spectral_class(Asteroid, SpectralClass)
member_of(Asteroid, AsteroidPopulation)
may_belong_to_family(Asteroid, AsteroidFamily)
participates_in_resonance(Asteroid, OrbitalResonance)
has_satellite(Asteroid, CelestialBody)
observed_by(Asteroid, Instrument)
supported_by(Claim, Observation)
may_collide_with(Asteroid, CelestialBody)

06. IDENTITY AND NAMING
An asteroid identifier is distinct from its provisional designation, permanent number, name, and survey alias.
RULE: matching labels alone do not establish identity; require catalogue cross-identifiers and compatible orbital solutions.
RULE: new orbit solutions update state estimates, not necessarily the physical object's identity.

07. CLASSIFICATION
Main-belt asteroids predominantly occupy the region between Mars and Jupiter.
Near-Earth asteroid classification is based on orbital criteria, not a prediction of impact.
Trojan asteroids occupy dynamical regions associated with a planet's L4/L5 vicinity; actual motion is librational.
Asteroid families may be inferred from clustered proper orbital elements and physical evidence.
Spectral taxonomy is observational and does not uniquely determine bulk composition.

08. ORBITAL DYNAMICS
For a two-body approximation: n = sqrt(mu/a^3), where mu = G(M_central + m).
Kepler's third law: T = 2*pi*sqrt(a^3/mu).
For an ellipse: r = a(1-e^2)/(1+e*cos(nu)).
Specific orbital energy: epsilon = v^2/2 - mu/r = -mu/(2a).
Specific angular momentum: h = r cross v.
These are idealised relations; precision ephemerides require perturbations and numerical integration.

09. PERTURBATIONS
MODEL acceleration = central_gravity + planetary_perturbations + non_gravitational_terms.
Non-gravitational terms may include Yarkovsky thermal recoil; significance depends on size, spin and material parameters.
Resonances can alter long-term orbital evolution.
CHAOTIC_DYNAMICS: long-horizon trajectories may diverge under small initial uncertainties.

10. PHYSICAL STRUCTURE
Possible internal structures include coherent monoliths, fractured aggregates and gravitational rubble piles.
Shape may be irregular; equivalent-sphere diameters are modelling summaries.
Porosity and composition affect bulk density and collisional response.

11. MASS, VOLUME AND DENSITY
rho = m/V.
For an equivalent sphere: V = (4/3)*pi*R^3.
Gravitational parameter: mu_ast = G*m.
Surface gravity approximation for a sphere: g = G*m/R^2.
ESCAPE_SPEED approximate: v_esc = sqrt(2*G*m/R).
VALIDITY: spherical, isolated, non-rotating approximations; irregular shapes and spin require fuller models.

12. ROTATION AND SPIN
Spin state = {period, pole_orientation, phase, precession_model?}.
Rotation periods may be derived from lightcurves but aliases and shape effects must be considered.
Rapid rotation may constrain cohesion and bulk density, but does not alone establish internal structure.

13. SURFACE AND COMPOSITION
Observable evidence: reflectance spectrum, thermal infrared emission, radar, imaging, in-situ samples.
Possible surface attributes: regolith, boulders, impact craters, space weathering, thermal inertia.
CLAIM: spectral class is a proxy, not a direct chemical assay.

14. THERMAL MODEL
Equilibrium temperature approximation: T = [((1-A)*S)/(eta*epsilon*sigma)]^(1/4).
Here A = Bond albedo, S = incident solar flux, eta = model factor, epsilon = emissivity, sigma = Stefan-Boltzmann constant.
MODEL_LIMIT: geometry, heat storage, rotation and thermal inertia can invalidate a simple equilibrium approximation.

15. COLLISIONS AND IMPACTS
An orbit intersection does not prove a collision.
Impact probability requires propagated uncertainties, timing and dynamical modelling.
Kinetic energy of an impactor: E_k = 0.5*m*v^2.
Impact outcomes depend on angle, velocity, target structure and composition.

16. OBSERVATIONAL INFERENCE
Astrometry constrains sky position and orbit.
Photometry constrains brightness and can inform rotation, shape and size with model assumptions.
Thermal radiometry can constrain diameter and albedo jointly under a thermal model.
Radar can constrain range, range rate and shape for suitable targets.
Spectroscopy informs mineralogical hypotheses with uncertainty.

17. UNCERTAINTY
Every estimated property should carry units, epoch, method and uncertainty.
Covariance matrices encode correlated orbital-element uncertainty under a specified parameterisation.
Confidence scores represent assessed support, not an automatic physical probability.
Do not substitute a point estimate for a full impact-risk distribution.

18. INFERENCE RULES
RULE R01: Asteroid(x) -> CelestialBody(x).
RULE R02: has_orbit(x,o) AND epoch(o,t) -> orbit_valid_at(x,t).
RULE R03: mass(x,m) AND volume(x,V) AND V>0 -> density(x,m/V).
RULE R04: measured_period(x,P) AND P>0 -> angular_frequency(x,2*pi/P).
RULE R05: spectral_class(x,c) -> candidate_composition(x,composition_hypotheses(c)); NOT confirmed_composition.
RULE R06: intersects_orbit(x,Earth) -/-> impacts(x,Earth).
RULE R07: has_evidence(claim,e) AND valid_provenance(e) -> eligible_for_review(claim).
RULE R08: updated_orbit_solution(x,o2) -> invalidate_dependent_ephemerides(x) until recomputed.

19. SEMANTIC EQUIVALENCE
Asteroid ~ minor planet ONLY within cataloguing contexts where terms are operationally aligned.
Asteroid != meteoroid; asteroid != meteor; asteroid != meteorite.
NearEarthAsteroid != EarthImpactThreat.
SpectralClass != chemical_composition.
DiameterEstimate != directly_measured_diameter unless the method supports that description.

20. WORKED EXAMPLE: ORBITAL PERIOD
ASSUME heliocentric two-body orbit with a = 2.5 AU and negligible asteroid mass.
Using T_years approximately sqrt(a_AU^3): T = sqrt(15.625) = 3.953 years.
OUTPUT: approximate period 3.95 Earth years.
QUALIFICATION: ignores perturbations and assumes standard astronomical units.

21. WORKED EXAMPLE: DENSITY
ASSUME diameter = 1,000 m, radius = 500 m, mass = 1.0e12 kg.
V = (4/3)*pi*(500 m)^3 approximately 5.236e8 m^3.
rho = 1.0e12 / 5.236e8 approximately 1.91e3 kg/m^3.
OUTPUT: approximately 1,910 kg/m^3 under spherical assumption.

22. VALIDATION TESTS
TEST V01: reject negative mass, radius or volume.
TEST V02: reject confidence outside [0,1].
TEST V03: require reference frame and epoch for orbit elements.
TEST V04: reject inference that an orbit-crossing asteroid must impact Earth.
TEST V05: ensure dimensional consistency of equations.
TEST V06: distinguish observed from model-inferred properties.
TEST V07: flag missing uncertainty or provenance for quantitative scientific claims.
TEST V08: check that every relation has valid subject/object types.
TEST V09: preserve aliases without merging unrelated objects.
TEST V10: check that all sections and END marker are present.

23. FLOW EXECUTION
INPUT: asteroid observations, catalogue identifiers, physical-property measurements, model assumptions.
STEP 1: normalise units, timestamps and reference frames.
STEP 2: resolve entity identity and aliases.
STEP 3: build typed entity-relation graph.
STEP 4: attach evidence and provenance.
STEP 5: evaluate physical and orbital constraints.
STEP 6: derive permitted quantities with propagated uncertainty where available.
STEP 7: validate claims and mark unresolved conflicts.
STEP 8: emit AI-consumable graph and audit trail.
OUTPUT: validated ontology graph plus qualified inference records.

24. CONFIDENCE MODEL
confidence(claim) = calibrated_assessment(evidence_quality, method_validity, agreement, provenance).
No universal numerical confidence is asserted without calibration data.
Low-confidence hypotheses must remain explicitly labelled.

25. FLOW_HASH
HASH_ALGORITHM: SHA-256.
HASH_INPUT: canonical UTF-8 serialisation of version, typed entities, relations, equations and validation rules.
FLOW_HASH_VALUE: COMPUTE_AT_DEPLOYMENT (not fabricated).

26. UPDATE_MODEL
Triggers: revised asteroid catalogue, new astrometry, updated orbit, spectral reclassification, new physical measurement, revised taxonomy.
Policy: version every substantive change; retain previous claims and provenance; recompute affected derived relations.

27. AI_CONSUMPTION
FORMAT: UTF-8 plain text; structured typed triples and rules.
CAPABILITIES: entity linking, retrieval, uncertainty-aware reasoning, orbital/physical property validation.
RESTRICTIONS: no unsupported impact prediction; no composition certainty from taxonomy alone; no unqualified extrapolation beyond model validity.

28. CROSS-ONTOLOGY LINKS
Parent: Astronomical Entities.
Related: Celestial Body Ontology; Planet Ontology; Moon Ontology; Orbital Mechanics; Gravity; Matter; Material; Impact Processes; Scientific Measurement.

29. COMPLETENESS AUDIT
Required: header, identity, types, relationships, equations, inference, examples, validation, semantic equivalence, confidence, hash, update model, AI consumption, END marker.
Status: all required components present in this document.

END FLOW ALGEBRA — ASTEROID ONTOLOGY — v1.1