Abstract
The capture of the irregular satellites of the giant planets and the Trojans of Jupiter and Neptune, as well as their physical and dynamical properties, can be explained neither by the simple mass growth of the giant planets nor by their migration in the planetesimal disk. Only the planetary instability described by the Nice model, with its close encounters between planets, can account for the existence and characteristics of these populations. Together with planetary orbits, the existence and properties of the irregular satellites of the giant planets and the Trojans of Jupiter and Neptune constitute the main proof of the validity of the Nice model.