translation.en: Now, the Moon has no atmosphere, so micrometeorites come in continuously, and the whole surface of the Moon is covered with powder now, because for four billion years it's been bombarded by micrometeorites, and when micrometeorites come in at about 20 to 60,000 miles an hour, they vaporize on contact.
translation.zh: 因为月球没有大气层 所以 会不断受到陨尘的袭击 月球表面 如今呈粉末状 就是由于40亿年来 不断被陨尘撞击的结果 当陨尘以 每小时20到六万英里的速度袭来时 一旦击中目标便会气化