Extra exam question E3A01

WhyThe maximum practical ground-surface separation between two stations communicating by EME is roughly 12,000 miles, limited by needing the moon visible to both stations at once. Two stations can work each other by EME as long as the moon is above the horizon, "visible," to both of them at once, which can put roughly 12,000 miles of Earth surface between them, close to the practical limit set by simultaneous line-of-sight to the moon rather than by the moon's own distance, answer D. The moon's perigee or apogee position changes the path loss of an EME contact, not the maximum ground-surface separation between the two stations.