How to Calculate Roche Limit
What is Roche Limit?
Roche limit is minimum distance satellite can orbit before tidal forces exceed self-gravity, disrupting it into rings.
Step-by-Step Guide
- 1Input primary density, satellite density, and mass ratio
- 2Calculate rigid or fluid limit depending on satellite type
- 3Results show minimum stable orbital distance
Worked Examples
Input
Earth-Moon: Roche limit ~2.46 Earth radii (within Moon orbit)
Result
Moon stable but gradually receding
Currently ~384,400 km
Common Mistakes to Avoid
- ✕Confusing rigid and fluid Roche limits
- ✕Not accounting for density differences
Frequently Asked Questions
Are Saturn rings inside Roche limit?
Yes, explaining why rings exist instead of moon.
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