Dynamical evolution of Earth’s quasi-satellites: 2004 GU9 and 2006 FV35

We study the dynamical evolution of Asteroids (164207) 2004 GU₉ and 2006 FV₃₅, which are currently Earth quasi-satellites (QS). Our analysis is based on numerical computation of their orbits, and we also applied the theory of co-orbital motion developed in Wajer (Wajer, P. [2009]. Icarus 200, 147-153) to describe and analyze the objects’ dynamics. 2004 GU₉ stays as an Earth QS for about a 1000 years. In the present epoch it is in the middle of its stay in this regime. After leaving the QS orbit near 2600 this asteroid will move inside the Earth’s co-orbital region on a regular horseshoe (HS) orbit for a few 1000 years. Later, either HS-QS or HS-P transitions are possible, where P means “passing”. Although 2004 GU₉ moves primarily under the influence of the Sun and Earth, Venus plays a significant role in destabilizing the object’s orbit. Our analysis showed that the guiding center of 2006 FV₃₅ moves deep inside the averaged potential well, and since the asteroid’s argument of perihelion precesses at a rate of approximately , it prevents the QS state begin left for a long period of time; consequently the asteroid has occupied this state for about 10⁴ years and will stay in this orbit for about 800 more years. Near 2800 the asteroid’s close approach with Venus will cause it to exit the QS state, but probably it will still be moving inside the Earth’s co-orbital region and will experience transitions between HS, TP (tadpole) and P types of motion.