Cyllene is about 2 kilometres in diameter , and orbits Jupiter at an average distance of 23,396,000 km in 731.099 days , at an inclination of 140 Â to the ecliptic ( 140 Â to Jupiter 's equator ) , with an eccentricity of 0.4116 . Cyllene is about 2 kilometres in diameter , and orbits Jupiter at an average distance of 23,396 Mm in 731.099 days , at an inclination of 140 Â to the ecliptic ( 140 Â to Jupiter 's equator ) , in a retrograde direction and with an eccentricity of 0.4116 .