Trojan (celestial body) whatever the planet and trojan masses. And if = , then both must exceed 13+√168 ≈ 25.9615. But all this assumes a three-body system: once other bodies are introduced, even if distant and small, stability of the system requires larger ratios. Trojan (celestial body) In astronomy, a trojan is a minor planet or moon that shares the orbit of a planet or larger moon, wherein the trojan remains in the same, stable position relative to the larger object. In particular, a trojan remains near one of the two trojan points of stability – designated and – which lie approximately 60°
Celestial spheres was a lasting remnant of physical celestial spheres in Kepler's cosmology. In Cicero's "Dream of Scipio," the elder Scipio Africanus describes an ascent through the celestial spheres, compared to which the Earth and the Roman Empire dwindle into insignificance. A commentary on the "Dream of Scipio" by the Roman writer Macrobius, which included a discussion of the various schools of thought on the order of the spheres, did much to spread the idea of the celestial spheres through the Early Middle Ages. Some late medieval figures noted that the celestial spheres' physical order was inverse to their order on the