In this image, we are looking at a volume of space 100 000 km on a side. The Moon, about 1/4th the diameter of Earth, is 30 cm away at this scale. We are viewing the Earth from a point half the distance to our Moon. We are far above the orbiting geosynchronous satellites that provide nearly instantaneous global communication. A geosynchronous satellite orbits at an altitude of roughly 40 000 km above the equator so that the satellite's orbital velocity keeps it always directly above the same point on the Earth's surface. Science fiction and non-fiction author Arthur C. Clark was the first to suggest the importance of the geosynchronous orbit for communication.
Copyright © 2016 by Bruce Bryson