Time evolution of the (a) semimajor axis, (b) eccentricity, and (c) 5:7 SOR resonant angle of a test particle initially placed at the radial center of Q2R. The blue curves correspond to the configuration without the putative satellite, while the black and red curves correspond to configurations including a putative satellite at 5676 and 5910 km, respectively. The resonant angle is defined as ﹩{\phi }_{57}^{Q}=7\lambda -\frac{10\pi }{{T}_{Q}}t-2\varpi ﹩, where λ and ϖ denote the particle mean longitude and longitude of pericenter, respectively.