Due and Scope
Due: [insert date]. Submit evidence matrices, calculations, and a mission traceability table.
Learning objectives: evaluate habitability claims using environment, energy, chemistry, stability, and evidence quality; distinguish habitability from life detection; connect mission questions to measurements, instruments, uncertainties, and planetary protection.
Instructions: Keep student-facing claims cautious. Cite any outside mission example used. Revisions may be resubmitted with a change note.
Problems
1. Habitability Evidence Matrix 25 points
A press release says a newly studied icy moon is "possibly habitable." Available observations: surface temperature 80 K; induced magnetic signal consistent with a conductive layer; plume-like feature detected once; surface salts near fractures; strong radiation environment; orbital resonance with a neighboring moon.
- Create a matrix with columns for liquid environment, energy source, chemistry, stability, and evidence quality.
- For each category, list supporting evidence and one uncertainty.
- Assign each category a score from 0 to 2 and justify the score.
- Write a cautious conclusion that does not claim life detection.
Deliverables: scored matrix and 180-220 word conclusion.
2. Insolation and Habitable-Zone Caution 25 points
A planet orbits a star with luminosity \(0.25L_\odot\) at 0.50 AU. A second planet orbits a Sun-like star at 1.60 AU. Use relative flux \(S/S_E=(L/L_\odot)/a^2\).
- Compute relative flux for both planets.
- Compare each with Earth.
- Explain why flux alone is insufficient for habitability.
- List four follow-up measurements needed before treating either planet as a serious habitability candidate.
Deliverables: flux calculations and follow-up measurement list.
3. Planetary Protection Risk Chain 25 points
A lander is proposed for a potentially habitable icy moon. The prelaunch bioburden is estimated at \(3.0\times10^4\) viable spores. Cleaning reduces this by a factor of \(10^3\). Cruise radiation reduces survivors by another factor of 50. Assume a 10% chance that remaining organisms reach a warm, wet niche after landing.
- Estimate the expected number of viable organisms at landing.
- Estimate the expected number reaching a warm, wet niche.
- Explain why even a small expected value matters scientifically.
- State two mission-design choices that reduce forward-contamination risk.
Deliverables: calculation chain and planetary-protection interpretation.
4. Mission Traceability Table 25 points
Design a mission concept to test this science question: "Does Enceladus exchange material between a subsurface ocean and space?" You have room for three investigations.
- For each investigation, state the measurement, instrument type, expected observable, and primary uncertainty.
- Classify the mission architecture as flyby, orbiter, lander, sample return, or remote telescope, and justify the tradeoff.
- Identify one validation measurement that would disconfirm your preferred interpretation.
- State one planetary-protection requirement relevant to your architecture.
Deliverables: traceability table and 200-250 word mission rationale.
OpenStax Companion Practice
Recommended for additional practice: OpenStax Astronomy 2e, Chapter 12, Review Questions 3 and 12; Thought Questions 13, 16, and 19; Chapter 13, Thought Questions 16-18; Chapter 14, Review Questions 8-9 and Thought Question 19. These entries support synthesis and mission reasoning; verify numbering against the adopted PDF before LMS release.