Replica of the Apollo 17 sun compass constructed from the actual template in Apollo flight director Neil Hutchinson’s personal collection. The fully functional replica features a moveable compass dial, a foldable sundial gnomon, and a bubble level. The front features an 8″ diameter rotating disc which depicts "East Massif” and “Sculptured Hills,” and the main 10.25″ card provides instructions for "Bearing Determination" and "Return to LM." The reverse provides "Nominal Shadow Data.” In fine condition.
This particular sun compass, made of heavy cardstock, is a unique and inventive instrument designed to be lightweight and sturdy. The sun compass would have been used on the lunar surface to assist the moonwalkers in the event the rover broke down and they had to walk back to the lunar module, using the sun’s shadow and the time to find the best route to the lunar residency.
Sun compasses date back into the ages and are used to determine direction by the use of the sun and time of day. Due to the failure of magnetic compasses in the high latitudes, the sun compass was used in the exploration of the Earth's poles. Polar explorer Adm. Richard Byrd used a sun compass designed by Albert Bumstead of the NGS to chart his way to the North Pole by air in the 1920s. Since the moon has a very weak magnetosphere, a normal compass would be of no use in determining direction. The sun compass included here solved the problem of manual navigation on the moon.
