MANHATTANHENGE: Why It Happens

Twice a year, the sun falls into exact alignment with the Manhattan street grid, offering incredible sunsets that fully illuminate the cross-streets. The most dramatic photographs could arguably be taken amidst the notable architecture on 34th and 42nd street, as seen here:

This phenomenon has been nicknamed “Manhattanhenge” for its similarity to Stonehenge — but this moniker would imply a sense of mystery over the physical remnants and functionalities of a bygone civilization. Rather, this bi-annual occurrence is unique to Manhattan because of a fortuitous street plan and flat topography that, in concurrence, provide clear, straight views to the horizon.

The Manhattan grid is set 28.9 degrees east of due north — causing this event to be offset from the vernal and autumnal equinoxes. The systemization of streets is the legacy of the New York City Commissioners’ Plan of 1811. According to Kate Ascher, author of The Works and a professor of mine, while the grid plan “succeeded in its primary purpose of underpinning orderly real estate development, it arguably failed to provide capacity for the heavy north-south traffic that would later be addressed by the development of the subways.” The grid plan called for east-west streets to be set closer than avenues.

The side effects of the layout manifest most discernibly in the projects to rectify overcrowding and notoriously slow/unreliable bus service on the east side, including construction of Second Avenue subway line (first proposed in 1920!) and trials for bus rapid transit (BRT), a pet project of mine.

NEXT MANHATTANHENGE:

When: July 11th and July 12th at 8:25pm. On July 11th, a half-sun will be visible on the horizon and on July 12th, the full sun.
Where: Weather permitting, Untapped New York will be meeting at 42nd St. and Lexington Avenue at 7:30pm on both days.

Update: Pictures from the 2009 Manhattanhenge!

Get in touch with the author @untappedmich.