quasi-satellite چونانماهواره، چونانبندهوار cunân-mâhvâré, cunân-bandevâr
*Fr.: quasi-satellite*
An asteroid moving around the Sun having the same mean motion and mean
→ *longitude* as a planet, but a different
→ *eccentricity*. The asteroid remains near the
planet much like a satellite even when its distance is large enough so
that it is well outside the planet's → *Hill sphere*.
The quasi-satellite motion is one class of possible
→ *co-orbital motion*s of small bodies in 1:1 mean-motion
→ *resonance* with a planet. If
the quasi-satellite orbit is coplanar with the planet, then the motion is stable in
the → *secular* approximation. When the orbits are inclined
enough, an asteroid can be trapped into such a motion for a
finite period of time. Earth has several quasi-satellites (mainly
3753 Cruithne, 2002 AA_{29}, 2003 YN_{107}), also does Venus
(the only one so far discovered, 2002 VE_{68}). The possibility of
such orbits was first suggested by J. Jackson (1913, MNRAS 74, 62). The term *quasi-satellite* was first used by S. Mikkola & K. Innanen
1997, The Dynamical Behaviour of our Planetary System; Proceedings, p. 345);
→ *quasi-*; → *satellite*. |