Hermippe is about 4 kilometres in diameter , and orbits Jupiter at an average distance of 21,182,000 km in 629.809 days , at an inclination of 151 Â to the ecliptic ( 149 Â to Jupiter 's equator ) , with an eccentricity of 0.2290 . Hermippe is about 4 kilometres in diameter , and orbits Jupiter at an average distance of 21,182 Mm in 629.809 days , at an inclination of 151 Â to the ecliptic ( 149 Â to Jupiter 's equator ) , in a retrograde direction and with an eccentricity of 0.2290 .