- There are now known six binary KBOs (besides Pluto).
- First discovered 12/00 (Veillet with CHFT).
- Semi-major axes very large (~10,000 km)
- Obviously could be observational biases.
- Orbital velocity only ~3m/s!
- Thus, they are very easy to disrupt.
- So, locations may place important constraints on the history of the Kuiper belt.
- Binary forming impact could(would?) kick KBO out of resonance.
Binary formed before resonance (Stern).
- Whatever cause resonance trapping preserved binaries.
Migration is still OK.
- All known main belt binary KBOs are part of cold population. Statistically significant?
Perhaps excitation process destroys binaries.