Researchers offer first explanation for the near constant scale of the gas planet satellite systems

Red, blue and green curves are results of three simulations of satellite growth and loss within a disk supplied by an inflow of gas and solids. Plotted is the total mass of all orbiting satellites in each case scaled to the planet’s mass, MT/MP, as a function of the total fraction of the planet’s mass delivered by the inflow, Min/MP, which is a quantity that is proportional to the total elapsed simulation time. For comparison, the black dotted lines are corresponding values for the satellite systems of Jupiter, Saturn and Uranus, respectively. In these simulations, a constant inflow rate is considered in order to illustrate cycles of satellite growth and loss. The inflow of solid material to the protosatellite disk causes MT/MP to increase with time until large satellites form and are lost to collision with the planet (indicated by the discrete jumps downward in MT/MP). Once large satellites have been lost to orbital decay, continued inflow causes a new generation of satellites to grow, and the cycle repeats. Throughout the process, MT/MP oscillates about a fairly constant value. The three simulations consider a wide range (a span of a factor of 500) for the key parameters that affect the amount of gas in the disk when large satellites form. Credit: Southwest Research Institute