The new residence of lunar immigrants

The detector can be regarded as a particle in the vast universe, and both the particle and the moon have a certain mass. According to the law of universal gravitation, this particle is subject to universal gravitation from the moon. In the ideal environment of the universe (that is, without remembering other resistances), the mechanical energy of particles is conserved. In order to reach a higher orbit, the detector must accelerate, but its orbital speed is decreasing. When it is captured by the moon's orbit, it enters the orbit around the moon, the orbital speed gradually increases, and then the kinetic energy increases continuously. When ek = w/2, it can't reach the moon, let alone be captured by the lunar orbit.

The premise of these is that the speed of the detector must not be particularly large. When its speed is particularly high, it can't be answered by Newton's classical mechanics, because its mass will change at this time, so Einstein's theory of relativity is needed.