The system's secondary-to-primary mean-diameter ratio is 0.643. The Johnston archive derives a diameter of 9.39 kilometers for the moon, and estimates that it has a semi-major axis of approximately 31 kilometers.
The ratio of the secondary to primary diameters in this system is 0.643. The Johnston archive calculates a diameter of 9.39 kilometers for the moon, while estimating its semi-major axis at roughly 31 kilometers.