Manhattanhenge — sometimes referred to as the Manhattan Solstice — is an event during which the setting sun is aligned with the east–west streets of the main street grid of Manhattan, New York City. This occurs twice a year, on dates evenly spaced around thesummer solstice. The first Manhattanhenge occurs around May 28, while the second occurs around July 12.
The term "Manhattanhenge" was popularized by Neil deGrasse Tyson, an astrophysicist at the American Museum of Natural Historyand a native New Yorker. It is a reference to Stonehenge, a prehistoric monument located in Wiltshire, England, which was constructed so that the rising sun, seen from the center of the monument at the time of the summer solstice, aligns with the outer "Heel Stone".
The event has attracted increasing attention in recent years.
In the following table, "full sun" refers to occurrences of the full solar disk just above the horizon, and "half sun" refers to occurrences of the solar disk partially hidden below the horizon.
|May 31, 2011||8:17 p.m.||Full sun|
|July 12, 2011||8:25 p.m.||Full sun|
|July 13, 2011||8:25 p.m.||Half sun|
|May 29, 2012||8:17 p.m.||Half sun|
|May 30, 2012||8:16 p.m.||Full sun|
|July 11, 2012||8:24 p.m.||Full sun|
|July 12, 2012||8:25 p.m.||Half sun|
|May 28, 2013||8:16 p.m.||Half sun|
|May 29, 2013||8:15 p.m.||Full sun|
|July 12, 2013||8:23 p.m.||Full sun|
|July 13, 2013||8:24 p.m.||Half sun|
|May 29, 2014||8:16 p.m.||Half sun|
|May 30, 2014||8:18 p.m.||Full sun|
|July 11, 2014||8:24 p.m.||Full sun|
|July 12, 2014||8:25 p.m.||Half sun|
|May 29, 2015||8:12 p.m.||Half sun|
|May 30, 2015||8:12 p.m.||Full sun|
|July 12, 2015||8:20 p.m.||Full sun|
|July 13, 2015||8:21 p.m.||Half sun|
|May 29, 2016||8:12 p.m.||Half sun|
|May 30, 2016||8:12 p.m.||Full sun|
|July 11, 2016||8:20 p.m.||Full sun|
|July 12, 2016||8:20 p.m.||Half sun|
The same phenomenon happens in other cities with a uniform street grid and an unobstructed view of the horizon, with each instance depending on the city's grid plan, surrounding topography and flora (for instance, a city surrounded by hills, mountains or forestry would not experience the effect even if its streets were laid out perfectly). Such occurrences would coincide with the vernal and autumnal equinox only if the grid plan were laid out precisely north-south and east-west, and perfectly aligned with true north as opposed to magnetic north. The situation in Baltimore comes fairly close, with its sunrises on March 25 and September 18 and sunsets on March 12 and September 29. In Chicago, the setting sun lines up with the grid system on September 25 and March 20, a phenomenon known similarly asChicagohenge. In Toronto, the setting sun lines up with the east–west streets on October 25 and February 16, a phenomenon known locally as Torontohenge. InMontreal, there may be a Montrealhenge each year on July 12. When the architects designing the centre of Milton Keynes in the UK discovered its main street almost framed the rising sun on Midsummer Day, they consulted Greenwich Observatory to obtain the exact angle required at their latitude, and persuaded their engineers to shift the grid of roads a few degrees.
"MIThenge" is the twice-yearly event when the setting sun can be seen across the length of the "Infinite Corridor", in the central campus of the Massachusetts Institute of Technology (MIT), in Cambridge, Massachusetts. That event was first advertised in 1975, in a poster that included a drawing of Stonehenge.