Two regions where plutinos with larger masses might exist

Up to now nearly 1000 small objects have been found in the solar system beyond Neptune. They are called Kuiper Belt Objects (KBOs) or Edgeworth-Kuiper Belt Objects. A group of KBOs named plutinos are in the 3:2 mean motion resonance with Neptune, and Pluto is one of them. Since the discovery of the first KBO in 1992, several small-scale surveys have been carried out and a few large KBOs are discovered. By numerical calculations we have found two regions in the space of orbital elements, where, just as Pluto, objects are trapped in three resonances. These resonances protect Pluto and plutinos from the strong perturbation of Neptune. Furthermore, objects in these two regions will avoid close encounters with Pluto as well. Consequently, in these two regions astronomers might discover some plutinos with larger masses.