 This is the second known example of a Laplace resonance, the first being Jupiter's moons Io, Europa and Ganymede.The orbital semimajor axis is only 0.13 AU, around a third of the average distance between Mercury and the Sun, and is more eccentric than the orbit of any of the major planets of our solar system.Despite this, it is located in the inner regions of the system's habitable zone, since Gliese 876 is such an intrinsically faint star.