| 1. Domain | 1.1 Scope of the Domain | Boundaries | The range of phenomena the science includes and excludes. | Includes the formation, structure, composition, atmospheres, surfaces, climates, and evolution of planets and moons inside and outside the solar system; includes detection and characterization of exoplanets, planetary interiors, orbital dynamics, and habitability studies. Excludes stellar physics, galactic scale processes, and cosmological evolution except where they affect planetary formation. |
| | Scale | The spatial, temporal, or organizational level at which the science operates (e.g., quantum, cellular, social, cosmic). | Operates from meter scale surface features to planetary radii thousands of kilometers across, and orbital scales from fractions of an astronomical unit to many astronomical units; time scales range from atmospheric cycles to billions of years of planetary evolution. |
| 1.2 Ontological Commitments | Entities | The kinds of things assumed to exist within the domain (particles, organisms, agents, fields, etc.). | Planets, moons, atmospheres, surfaces, interiors, mantles, cores, magnetic fields, rings, minor bodies, exoplanets, debris disks, and external influences such as host stars or stellar radiation. |
| | Properties | The fundamental attributes these entities possess (mass, charge, genotype, preference, etc.). | Mass, radius, density, composition, temperature, albedo, atmospheric pressure, orbital parameters, surface gravity, magnetic field strength, and internal heat flow. |
| | Categories | The basic ontological types used to classify domain elements (substances, processes, relations, structures). | Planet types, atmospheric regimes, surface processes, orbital types, evolutionary pathways, and internal structural layers. |
| 1.3 State-Variables | Variables | The measurable or definable properties that describe system conditions. | Temperature, pressure, density, atmospheric composition, orbital period, eccentricity, inclination, surface composition, internal heat, and stellar flux. |
| | Parameterization | How variables encode and represent the system’s state. | States encoded by atmospheric profiles, orbital elements, planetary mass and radius values, spectral signatures, internal structure models, and climate or energy balance descriptors. |
| 1.4 Admissible Idealizations | Simplifications | Conceptual reductions used to make the domain tractable (point masses, rational agents, perfect gases). | Spherical planet approximation, hydrostatic equilibrium, simplified atmospheric models, uniform composition assumptions, treating planets as point masses in orbital calculations, and ignoring minor heat or chemical sources. |
| | Validity Conditions | The limits and contexts in which idealizations hold or break down. | Valid when rotation is moderate, atmosphere is stable, internal structure is layered predictably, and planet star interactions are not extreme; breaks down under rapid rotation, strong tidal forces, or chaotic climate regimes. |
| 1.5 Domain Assumptions | Structural Assumptions | Background ontological stances such as determinism, continuity, randomness, discreteness. | Assumes planets obey gravitational and thermodynamic laws, atmospheres follow fluid principles, internal layers behave by known physical rules, and exoplanet detection signals reflect real orbital or atmospheric behavior. |
| | Implicit Commitments | Unstated but necessary assumptions that shape the field’s conceptual structure. | Assumes observational models map accurately to physical properties, simplified internal or atmospheric models capture essential physics, and orbital dynamics reflect real gravitational interactions. |
| 1.6 Internal Coherence Requirements | Consistency | The demand that domain concepts do not contradict one another. | Requires agreement between orbital data, atmospheric measurements, internal structure models, and observed physical properties such as density, climate, and surface conditions. |
| | Compatibility | The requirement that entities, variables, and assumptions fit together into a unified descriptive framework. | Entities, variables, and assumptions must unify orbital dynamics, interior physics, atmospheric processes, composition, and evolution into a coherent planetary system description. |
| 2. Evidence Layer | 2.1 Observable Phenomena | Observables | The aspects of the domain that can produce detectable signals accessible to measurement. | Detectable signals include planetary transits, radial velocity shifts, direct imaging brightness, thermal emission, reflected light curves, atmospheric spectra, surface composition signatures, orbital motion, magnetic field indicators, and gravitational interactions. |
| | Detection Limits | The boundaries of what can be resolved or sensed by current instruments or methods. | Limited by telescope sensitivity, atmospheric interference, contrast ratios between planet and star, angular resolution, spectral resolution, noise levels, and ability to detect small planets or long period orbits. |
| 2.2 Measurement Systems | Units | Standardized quantifications (meters, seconds, volts, decibels, dollars, etc.) necessary for consistent comparison. | Uses meters, seconds, astronomical units, years, kelvins, watts, magnitudes, kilometers per second, flux units, and mass or radius expressed in Earth or Jupiter units. |
| | Instruments | Devices and tools (microscopes, spectrometers, sensors, surveys, detectors) used to produce measurements. | Instruments include space telescopes, ground telescopes, spectrographs, photometers, interferometers, transit survey satellites, radial velocity spectrometers, direct imaging coronagraphs, and infrared detectors. |
| 2.3 Operational Definitions | Definitions | Terms defined by specific measurement procedures, ensuring empirical clarity. | Quantities such as transit depth, radial velocity amplitude, albedo, atmospheric composition, equilibrium temperature, and orbital elements are defined by standardized observational procedures. |
| | Procedures | The explicit steps required to perform a measurement in a reproducible way. | Procedures include light curve extraction, radial velocity fitting, spectral retrieval, direct imaging data reduction, phase curve analysis, and correction for stellar activity or instrument drift. |
| 2.4 Data Acquisition | Protocols | Formal processes for gathering data under controlled or standardized conditions. | Data gathered through long term monitoring, repeated transits, multi wavelength observations, spectroscopic campaigns, image stacking, and coordinated observation schedules across instruments. |
| | Sampling | Rules determining which subset of the domain is measured and how representative it is. | Sampling rules include multiple transit sampling, time series photometry, wavelength binning, survey wide planet candidate selection criteria, and repeated follow up to confirm detection. |
| 2.5 Data Character & Format | Data Types | The form raw evidence takes (time series, spectra, images, counts, qualitative records). | Data appears as light curves, radial velocity curves, spectra, direct images, phase curves, temperature maps, transit timing variations, and orbital catalogs. |
| | Resolution | The granularity or precision with which data is captured. | Determined by detector sensitivity, spectral dispersion, time sampling, coronagraph contrast, instrument stability, and atmospheric transparency for ground based data. |
| 2.6 Reliability & Calibration | Calibration | Adjustment procedures ensuring instruments produce accurate results. | Calibration uses reference stars, detector flat fields, wavelength calibration lamps, pointing corrections, thermal background subtraction, and cross calibration with independent instruments. |
| | Error Characterization | Identification and quantification of noise, uncertainty, bias, and measurement error. | Errors arise from stellar activity, photon noise, atmospheric distortion for ground observations, instrument drift, contamination from nearby sources, transit timing uncertainties, and model degeneracies in spectral retrieval. |
| 3. Structural Layer | 3.1 Patterns & Regularities | Laws / Relations | Stable, repeatable patterns governing how observables behave across conditions. | Stable patterns include mass radius relations, temperature distance laws, atmospheric escape trends, star planet interaction relationships, orbital stability rules, and consistent climate energy balance patterns. |
| | Invariants | Quantities or properties that remain constant under transformations (symmetries, conservation laws). | Invariants include conservation of angular momentum in orbits, stable orbital resonances, persistent atmospheric ratios in equilibrium states, consistent density composition relationships, and long lived internal structural layering. |
| 3.2 Causal Architecture | Mechanisms | Underlying processes or structures that produce the observed regularities. | Mechanisms arise from gravitational interaction with host stars, heating from stellar radiation, atmospheric chemistry, internal heat flow, magnetic field generation, tidal interactions, and formation processes in protoplanetary disks. |
| | Pathways | Organized sequences of interactions forming a causal chain or network. | Pathways include accretion in disks, orbital migration, atmosphere formation and loss, geological and climate evolution, tidal locking, and long term surface or atmospheric transformations. |
| 3.3 Theoretical Vocabulary | Concepts | Core terms that encode the domain’s structure (force, gene, equilibrium, field). | Core terms include transit, radial velocity, albedo, equilibrium temperature, protoplanetary disk, habitability, atmospheric retrieval, orbital resonance, tidal locking, and escape velocity. |
| | Classifications | Taxonomies, categories, or typologies that organize entities and relations. | Classifies planets by size, mass, composition, atmosphere type, orbital regime, habitability potential, and by categories such as terrestrial, gas giant, ice giant, sub Neptune, and hot Jupiter. |
| 3.4 Formal Representations | Equations | Mathematical constructs expressing laws, relations, or mechanisms. | Includes orbital mechanics equations, energy balance formulas, mass radius relations, atmospheric scale height equations, tidal force relations, and models linking temperature, composition, and pressure. |
| | Models | Structured representations—mathematical, computational, or conceptual—used to predict and explain phenomena. | Includes climate models, atmospheric retrieval models, internal structure models, disk formation models, orbital evolution simulations, and habitability assessment models. |
| 3.5 Idealized Structures | Simplified Models | Purposeful abstractions that capture essential dynamics while omitting irrelevant detail. | Idealizations include spherical planets, uniform atmospheres, perfect blackbody emission, simplified chemistry, no clouds, circular orbits, and constant albedo assumptions. |
| | Limit Conditions | Regimes where specific models or approximations hold (classical vs. quantum, linear vs. nonlinear). | Valid when atmospheres are stable, orbital eccentricity is small, rotation is moderate, cloud cover is minimal, and star planet interactions remain within predictable ranges. |
| 3.6 Integrative Frameworks | Unifying Theories | Higher-order structures that connect disparate laws or mechanisms under a coherent whole. | Includes frameworks linking orbital dynamics, atmospheric physics, interior structure, stellar irradiation, formation theory, and climate models into a unified planetary system description. |
| | Interdisciplinary Links | Points where the theory connects to adjacent sciences or larger explanatory systems. | Links to astronomy, geology, atmospheric science, chemistry, fluid dynamics, climate science, astrobiology, and remote sensing. |
| 4. Method Layer | 4.1 Inquiry Design | Experimental Design | Structured plans for manipulating variables to test causal claims. | Direct manipulation of planets is impossible; instead, experiments are designed by selecting targets with specific orbital, atmospheric, or compositional properties to test predicted causal relationships. This includes comparing planets around different star types, examining planets across orbital distances, and analyzing systems with varying atmospheric signatures. |
| | Observational Design | Systematic approaches for gathering non-manipulated data (surveys, field studies, natural experiments). | Uses long term monitoring, transit surveys, radial velocity surveys, direct imaging campaigns, multi wavelength spectroscopy, and natural experiments such as eclipses, transits, and planetary phase variations. |
| 4.2 Testing & Validation | Hypothesis Testing | Procedures for evaluating whether evidence supports or contradicts specific claims. | Tests compare measured transit depths, spectra, radial velocity amplitudes, atmospheric retrieval outcomes, thermal phase variations, or orbital stability patterns against predictions from planetary, atmospheric, or interior models. |
| | Replication | The requirement that results be independently reproducible under similar conditions. | Replication involves confirming planetary detections across different telescopes, re observing transits, verifying radial velocity signals, checking spectral features with independent retrieval tools, and confirming orbital parameters across multiple datasets. |
| 4.3 Inference & Evaluation | Statistical Inference | Rules for drawing conclusions from noisy or incomplete data. | Methods include fitting transit curves, retrieving atmospheric compositions from spectra, analyzing noise in light curves, determining orbital elements, estimating surface temperatures, and quantifying uncertainties in mass, radius, and composition. |
| | Model Comparison | Criteria (fit, simplicity, predictive accuracy, robustness) used to evaluate competing models. | Models evaluated based on fit quality, predictive accuracy for observed spectra or light curves, robustness across wavelengths, physical consistency of retrieved compositions, and agreement with independent measurements such as mass or radius. |
| 4.4 Error Management | Error Analysis | Identification and quantification of random and systematic errors. | Errors arise from stellar activity, photon noise, instrument drift, atmospheric contamination in ground data, pointing instability, incomplete sampling of orbits, and degeneracies in atmospheric or interior modeling. |
| | Bias Control | Methods for minimizing subjective, instrumental, or procedural biases. | Bias minimized through blind fitting procedures, stellar variability correction, cross instrument calibration, consistent detrending of light curves, and independent validation using varying retrieval approaches. |
| 4.5 Adjudication & Revision | Peer Scrutiny | Collective evaluation of claims through critique, review, and debate. | Findings undergo peer review, cross comparison across surveys, conference evaluation, re observation using different methods, and theoretical scrutiny regarding atmospheric, interior, or dynamical interpretation. |
| | Theory Revision | Procedures for modifying, replacing, or discarding models based on new evidence. | Models updated when observations reveal unexpected atmospheric features, anomalous densities, unstable orbits, unpredicted climate patterns, or inconsistent thermal behavior; requires revising formation, interior, or atmospheric theory. |
| 4.6 Integrity Conditions | Transparency | Requirements to disclose methods, data, assumptions, and limitations. | Requires full disclosure of calibration steps, noise models, data reduction pipelines, orbital fitting assumptions, retrieval constraints, and limitations in detection or interpretation. |
| | Ethical Standards | Norms ensuring responsible conduct in experimentation, data handling, and publication. | Requires accurate reporting of uncertainties, avoiding selective data exclusion, responsible handling of observational resources, transparency in catalog release, and adherence to scientific integrity in planetary and exoplanet research. |