The planet Neptune is the farthest planet from the Sun. A satellite is orbiting around Neptune at a distance of 180 km. As the satellite orbits, only a portion of the planet may be seen at one time. This is referred to as the horizon circle and denoted by the variable H The distance between the satellite and the horizon circle H is 2,992 km. Find the approximate diameter of the planet Neptune. Round your final answer to the nearest kilometer..