ACT (Enhanced)ScienceHard
A scientist proposes a model to explain the formation of a planetary ring system. The model suggests that tidal forces from a nearby gas giant cause a large moon to break apart into smaller fragments, which then spread out to form a ring. Which of the following observations would most strongly support this model?
- AEvidence of significant volcanic activity on a large moon.
- BDetection of small, irregular moonlets within an existing ring system.
- CDiscovery of a new moon orbiting a gas giant.
- DObservation of a planet with no moons but a prominent ring system.
Show answer & explanationAnswer & explanation
Correct answer: B. Detection of small, irregular moonlets within an existing ring system.
The model specifically states that a moon breaks into 'smaller fragments' which then form the ring. Detecting these 'moonlets' (fragments of a larger body) within the ring system would directly support the mechanism proposed by the model.
Why the other options are wrong
- A. Volcanic activity on a moon doesn't explain its breaking apart into a ring system due to tidal forces.
- C. While related to gas giants, a new moon doesn't directly confirm the 'breaking apart' mechanism for ring formation.
- D. This contradicts the model's premise that a moon is necessary for the ring's formation.
Model Evaluation
Assessing how well a scientific model explains observed phenomena and predicts new ones.
- Models are simplifications of reality.
- Supported by consistent observations.
- Can be refined or rejected based on new evidence.
Memory trick: A good model 'fits' the facts like a glove.