Could the Earth-Moon system have shed a large angular momentum excess?
In plain words
Some impact scenarios that mix Earth and impactor well leave the system spinning about twice too fast. They work only if a gravitational resonance with the Sun later removed the extra spin.
Precise statement
High-angular-momentum scenarios (fast-spinning proto-Earth, synestia) require removal of roughly half the post-impact angular momentum, for example by evection resonance capture. Determine whether resonance capture and escape occur for realistic tidal parameters of the early Earth and Moon. An answer is a tidal-evolution calculation giving the angular momentum removed as a function of tidal model, with probability of the required outcome.
What would settle it
Coupled orbital and tidal evolution models with self-consistent Earth and Moon dissipation across the plausible parameter range.
Related problems
- Special case of Why are Earth and Moon isotopically nearly identical?