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
Dynamics of the celestial spheres bodies are moved by angelic spirits, which govern and move them. He maintained, instead, that "celestial bodies are moved by their own natural inclinations similar to weight". Just as heavy bodies are naturally moved by their own weight, which is an intrinsic active principle, so the celestial bodies are naturally moved by a similar intrinsic principle. Since the heavens are spherical, the only motion that could be natural to them is rotation. Kilwardby's idea had been earlier held by another Oxford scholar, John Blund (c. 1175–1248). In two slightly different discussions, John Buridan (c.1295–1358) suggested that when God created the