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Here author analyze the motion of a positively charged lunar dust grain in the presence of a shadowed crater at a negative potential in vacuum. Previous models describing the transport of charged lunar dust close to the surface have typically been limited to one-dimensional motion in the vertical direction, e.g. electrostatic levitation; however, the electric fields in the vicinity of shadowed craters will also have significant components in the horizontal directions. Authors propose a model that includes both the horizontal and vertical motion of charged dust grains near shadowed craters. They show that the dust grains execute oscillatory trajectories and present an expression for the period of oscillation drawing an analogy to the motion of a pendulum. One of the unresolved enigmas from the Apollo era is the existence and characteristics of highly electrically charged dust floating above the lunar surface. Potential evidence for this hypothesized phenomenon came from the Lunar Ejecta and Meteorites (LEAM) experiment on Apollo 17. This instrument reported up to hundreds of impact events per day around local sunrise and sunset whereas the expected impact rate of interplanetary dust particles was only a few impact detections per day. Recently, new arguments were raised that the signals recorded by LEAM may be caused by interferences from heater current switching which occurred most frequently near sunrise and sunset.