Historic marker reveals Lewes' contribution to global astronomy

A new historic marker unveiled at the entrance to Bethel Cemetery on Savannah Road Nov. 20 highlights Lewes' contribution to an 18th century global astronomy project.

In 1769, three surveyors from the American Philosophical Society in Philadelphia traveled to what was then known as Lewestown to monitor the Transit of Venus, when the planet passes in front of the Sun. The rare event occurs eight years apart every 120 years or so. The event last occurred in 2004 and 2012. The next transit is expected in December 2117 and December 2125.

Through research, it was determined the men set up a temporary observatory in what is now the Bethel Cemetery. The purpose of their journey to Lewes was to make scientific calculations as Venus made its journey across the face of the Sun, which could be combined with calculations taken from around the world to determine the distance between Earth and the Sun. By accurately measuring that distance, 18th century astronomers had a means to chart the entire solar system.