Description
Examines planetary system formation, geophysics, atmospheres, climate evolution, magnetic fields, impacts, rings, satellites, exoplanet comparisons, and the chemical and physical conditions that shape planetary environments (the official catalog description). Every physical tool (hydrostatic atmospheric structure, radiative-equilibrium temperature, the moment-of-inertia probe of interior structure, the Roche limit, tidal acceleration and heating, dynamo/magnetopause balance) is derived from first principles and then applied to real, published spacecraft-measured or literature data for the eight solar-system planets, their major satellites, and (in the capstone unit) the real, live-verified TRAPPIST-1 exoplanet system; see reference-log.md for full data provenance.
Learning Outcomes
- Compute planetary density, surface gravity, and escape velocity from mass and radius, and connect the results to the terrestrial/Jovian dichotomy and to atmospheric retention.
- Derive the solar-nebula frost-line location from radiative equilibrium and connect it quantitatively to the condensation sequence and the terrestrial/Jovian dichotomy.
- Use the moment of inertia factor to infer a planet's internal density distribution from spacecraft tracking data alone, and cross-check the inference against direct seismic evidence (Apollo, InSight).
- Derive the atmospheric hydrostatic and radiative-equilibrium equations and apply them to compute scale heights, equilibrium temperatures, and greenhouse excesses for real planets and the TRAPPIST-1 system.
- Derive the Jeans-escape parameter and the magnetopause pressure-balance standoff distance, and use both to explain why some atmospheres and magnetospheres persist while others do not.
- Derive the tidal-acceleration and Roche-limit formulas and apply them, correctly expressed as a fraction of a satellite's own surface gravity (never as a multiple of Earth's or the primary's gravity), to real ring systems and tidally heated icy satellites.
Textbook and Materials
Primary reading: OpenStax Astronomy 2e (free, openly licensed; local extracted reference copy under references/openstax-astronomy-2e-extracted.txt and problem index under references/source-indexes/), Chapters 7 and 9–13 (Other Worlds; Earth, Venus, Mars, and the Moon; the Giant Planets; Rings, Moons, and Pluto; Exoplanets). Chapter/section citations use the OpenStax Astronomy 2e native chapter numbering, following the ASTR 230/310 precedent for resolving the local extracted text/problem index's internal −1 chapter-numbering offset. Because ASTR 320 is an upper-division course, several core topics (the radiative-equilibrium disk-temperature/frost-line derivation, the moment-of-inertia interior-structure formalism, the hydrostatic scale-height and Jeans-escape derivations, the magnetopause pressure-balance derivation, and the Roche-limit and tidal-heating derivations) go beyond OpenStax Astronomy 2e's introductory, largely descriptive treatment; each lecture's slides and notes state explicitly where this course extends beyond the assigned introductory reading, exactly as in ASTR 310.
Assessment
| Component | Weight |
|---|---|
| Problem sets (7) | 30% |
| Labs (7) | 30% |
| Midterm exam (Lectures 1–7) | 15% |
| Final exam (cumulative, emphasis Lectures 8–14) | 20% |
| Participation and reading checks | 5% |
Lecture, Lab, and Problem-Set Cadence
The course runs 14 lectures, 7 labs, and 7 problem sets — a matched 1:1 biweekly cadence in which each lab and its paired problem set both follow the same two-lecture block, following the ASTR 230/ASTR 310 matched-cadence precedent rather than ASTR 210's uneven capstone cadence. This choice was confirmed against the actual lecture content (not assumed from the file counts alone): every lab and problem set below reuses the physical tool(s) derived in the immediately preceding two lectures (e.g., Lab 04/PS 04 apply Lecture 07's hydrostatic scale-height derivation and Lecture 08's radiative-equilibrium temperature derivation to Titan and to the eight solar-system planets, respectively), so a strict two-lecture-per-lab grid is the natural cadence here, exactly as in ASTR 230/310. One nuance specific to this course: the lecture sequence's six thematic units (see the schedule below) are of variable length — Unit 1 (Formation), Unit 2 (Interiors and Heat), and Unit 3 (Surfaces and Impacts) are each two lectures, but Unit 4 (Atmospheres) spans three lectures (07–09) and Unit 5 (Fields and Giants) spans three lectures (10–12), while Unit 6 (Satellites and Exoplanets) is two lectures (13–14). The lab/problem-set cadence nonetheless remains a strict two-lecture grid throughout (Lab 05/PS 05 pairs Lecture 09's atmospheric-escape derivation with Lecture 10's magnetic-field derivation, deliberately spanning the Unit 4/Unit 5 thematic boundary rather than waiting for a full three-lecture unit to conclude), so that no lab or problem set is ever separated from its most recently derived tool by more than one lecture. This is documented explicitly here, rather than left implicit, because the mismatch between thematic-unit length (2–3 lectures) and lab/problem-set cadence (always exactly 2 lectures) is not obvious from the schedule table alone.
| Lab/PS Unit | Lectures | Lab | Problem Set | Topic | Thematic Unit |
|---|---|---|---|---|---|
| 1 | 1–2 | Lab 01 | PS 01 | Comparative planetology basics; the solar nebula and condensation sequence | Unit 1: Formation and Architecture |
| 2 | 3–4 | Lab 02 | PS 02 | Planetary differentiation, interior structure, and heat budgets | Unit 2: Interiors and Heat |
| 3 | 5–6 | Lab 03 | PS 03 | Comparative surface geology and impact-crater age dating | Unit 3: Surfaces and Impacts |
| 4 | 7–8 | Lab 04 | PS 04 | Atmospheric hydrostatic structure and radiative equilibrium | Unit 4: Atmospheres (spans 3 lectures) |
| 5 | 9–10 | Lab 05 | PS 05 | Atmospheric escape and planetary magnetic fields (spans the Unit 4/5 boundary) | |
| 6 | 11–12 | Lab 06 | PS 06 | Giant-planet interiors, rings, and the Roche limit | Unit 5: Fields and Giants (spans 3 lectures; continued from row 5) |
| 7 | 13–14 | Lab 07 | PS 07 | Capstone: tidally heated icy satellites and the TRAPPIST-1 exoplanet system | Unit 6: Satellites and Exoplanets |
Revision Policy
High standards apply to all graded work. Problem sets and labs may be revised and resubmitted once for improved credit within one week of return, provided the resubmission includes a short change note identifying what was corrected and why (see each problem set's assessment instructions for full criteria).
Prerequisites Check
ASTR 120 (Solar System Astronomy) provides the descriptive foundation in solar-system inventory, planetary properties, and orbital mechanics that this course makes quantitative and derivation-based. CHEM 102 (General Chemistry II) supplies the chemical-bonding, phase-equilibrium, and thermochemistry background needed for the condensation-sequence, atmospheric-composition, and radiogenic-decay content in Lectures 02, 04, and 07–09. PHYS 172 (the second-semester calculus-based introductory physics sequence, covering thermodynamics, waves, and an introduction to fields) supplies the hydrostatic-equilibrium, ideal-gas, and basic electromagnetic-field background this course extends to planetary atmospheres (Lectures 07–09) and magnetic fields (Lecture 10). Because ASTR 320 does not require ASTR 230 or ASTR 310 as prerequisites, every first-principles derivation used here (radiative equilibrium, the moment-of-inertia formalism, hydrostatic scale height, the Roche limit, tidal acceleration, the magnetopause pressure balance) is developed from PHYS 172-level physics and mathematics rather than assuming the upper-division astrophysics toolkit built in ASTR 310; where a derivation parallels one also used in ASTR 310 (hydrostatic equilibrium, tidal forces), this is noted explicitly but the ASTR 320 derivation is self-contained.