Learning Objectives
- Compare Europa, Enceladus, Ganymede, Titan, and Callisto using measured and categorical evidence.
- Create a weighted score that is reproducible rather than impressionistic.
- Explain how confirmed plumes, induced magnetic fields, surface exchange, and energy sources affect habitability claims.
Preparation
Review Lectures 10 and 13 on icy moons, subsurface oceans, astrobiological habitability, and planetary protection.
Materials and Data
../data/lab-06-icy-moon-habitability.csv, a comparative table of icy-world size, density, temperature, ocean evidence, energy evidence, material exchange, and plume status.- Spreadsheet for weighted scoring.
- NASA Europa Clipper, Cassini, Cassini-Huygens, and Solar System Exploration pages.
Apparatus and Setup
- Open the CSV and add columns for water score, energy score, chemistry/exchange score, accessibility score, total score, and confidence flag.
- Use a 0-3 scale for each score: 0 = absent or unknown, 1 = weak/indirect, 2 = moderate, 3 = strong/direct.
- Adopt weights before scoring: water 35%, energy 25%, chemistry/exchange 25%, accessibility 15%.
Procedure
- Score each world in all four categories using only evidence in the CSV.
- Calculate a weighted total out of 3.0 for each world.
- Mark confidence as high, medium, or low depending on whether the evidence is direct measurement, model inference, or sparse/ambiguous.
- Recalculate totals with accessibility weight doubled and chemistry/exchange weight reduced. Note which rank changes.
- Choose one flagship mission target and one lower-cost reconnaissance target based on the two rankings.
Measurement Record
| World | Water score | Energy score | Chemistry/exchange score | Accessibility score | Weighted total |
|---|---|---|---|---|---|
| Europa | |||||
| Enceladus | |||||
| Ganymede | |||||
| Titan | |||||
| Callisto |
Analysis and Uncertainty
Because several entries are categorical, uncertainty is represented as score sensitivity. For any score based on indirect evidence, recalculate the total with that score plus or minus 1, bounded by 0 and 3. Report whether the top-ranked world remains top-ranked under that plausible scoring change. This is classification uncertainty, not measurement noise.
Deliverables
- Completed weighted score table and alternate-weight sensitivity table.
- One ranked bar chart with confidence flags.
- Mission-target recommendation that identifies the measurement most needed to reduce uncertainty.
- Provenance note citing NASA mission pages and
lab-06-icy-moon-habitability.csv.
Assessment Criteria
- Scoring rubric is applied consistently and transparently: 30%.
- Sensitivity analysis changes one assumption at a time: 20%.
- Recommendation follows from both score and uncertainty: 25%.
- Habitability language distinguishes evidence from desire for life detection: 15%.
- Complete provenance note: 10%.
References, Software, and Data Provenance
Data file: materials/ASTR120/data/lab-06-icy-moon-habitability.csv. Sources: NASA Europa Clipper mission science pages, NASA Cassini Enceladus science pages, NASA Cassini-Huygens Titan pages, and NASA Solar System Exploration pages for Ganymede and Callisto. Processing state: curated comparative teaching table with simplified categorical evidence fields.