Every once in a while such a retrograde loop occurs in the constellation Xin, one of the 28 ancient Chinese constellations and home to the star Antares, which the ancient Chinese considered the heavenly counterpart to the emperor.
火星繞日要六百八十七天，比地球慢，從地球上看，有一段時間火星就停滯在心宿位置，心宿是古代二十八星宿之一，心宿中的主星對應到地面就是九五之尊的帝王。