Luna 2 also crash land on the Moon in exactly the same way. Crash landing proved useful even after soft landing was mastered. NASA used crash landings to test whether Moon craters contained ice by crashing space probes into craters and testing the debris that got thrown out. The satellite's impact made it the first man-made object to land on another celestial body. "Luna 2" carried 5 different instruments to conduct various tests while it was on its way to the Moon. The scintillation counters would be used to measure any ionizing radiation; the Cherenkov radiation detectors would be measuring for electromagnetic
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