While I was visiting the urban canyons of New York City last weekend, a friend reminded me about the solar event called Manhattanhenge, a twice-yearly phenomenon when the arc of the sun across the evening sky aligns perfectly with the east-to-west streets on Manhattan island. The result is a spectacular sunset unobstructed by towering skyscrapers.
That got me to wondering about other possible city ’henges. I checked with Whet Moser at the Chicago Reader, and in short order he had calculated the dates of Chicagohenge using some handy photographer software.
In theory, any city with a street grid can have its own ’henge, including D.C. Our downtown grid, like Chicago’s, is a more or less a true east-west grid. So the next “DCHenge” sunset should occur a month from now on September 23, 2009, one day after the autumnal equinox:
But will it be cool? D.C. has a lower skyline than Manhattan and Chicago, and without the negative space between tall buildings, it may look like just another sunset. With that in mind, K or L streets NW seem like better candidates for DCHenge viewing than Constitution Avenue. (And depending on how closely the street runs due east and west, the 24th may be a better viewing date.)
There are other possibilities, too, if we take advantage of the diagonals:
New York Avenuehenge will occur on November 16, 2009, and Pennsylvaniahenge would appear to have been last week, on August 13th. (Do you always watch for Pennsylvaniahenge and then miss it? I always watch for Pennsylvaniahenge and then miss it.) Likewise Massachusettshenge, which was on August 1st or 2nd. The next Floridahenge will be July 17, 2010.
Does anyone have a good suggestion for making the most of the upcoming DCHenge? Or are we just doing for Manhattanhenge what Spinal Tap did for Stonehenge?
(Note: I am aware that “henge” does not mean what I am using it to mean: a suffix like ’gate from Watergate. While it would be cool to have a Watergatehenge, Virginia Avenue NW is just a bit too steeply angled.)
Photo of Manhattanhenge courtesy Wikimedia Commons. Maps made with The Photographer’s Ephemeris.
