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Free-fall F20

From Li & Liao (2019)

Free-fall F20 is a periodic orbit of the planar three-body problem: three equal masses that return to their starting positions and velocities every 8.8215 time units, published by Li & Liao (2019). Three bodies released from rest fall together, swing past each other and return to rest exactly where they started. It is unstable (largest Floquet multiplier 123), so a small nudge makes it unravel over a few periods. The bodies pass within 0.00378 of each other at a top speed of 16.6, line up 68 times a period, and the computed loop closes to 3.8×10⁻²⁵.

Measured over one period

Period: 8.821503387
Masses: 1 : 1 : 1
Energy: -4.63645
Angular momentum: 0
Closest approach: 0.003778
Top speed: 16.62
Path length: 33.322
Alignments per period: 68
Topology: 0 (free-group class)
Stability: unstable (|λ|max 12300)
Loop closure: 3.8×10⁻²⁵

Neighbours on the map

All Free-fall orbits, the families of periodic three-body orbits, or the atlas map.