Manhattanhenge, also inaccurately called the Manhattan

Solstice A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countr ...

, is an event during which the setting sun or the rising sun is aligned with the east–west streets of the main street grid of

Manhattan Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state ...

, New York City. The astrophysicist

Neil deGrasse Tyson Neil deGrasse Tyson ( or ; born October 5, 1958) is an American astrophysicist, author, and science communicator. Tyson studied at Harvard University, the University of Texas at Austin, and Columbia University. From 1991 to 1994, he was a p ...

has said that he coined the term, by analogy with Stonehenge. The sunsets and sunrises each align twice a year, on dates evenly spaced around the summer solstice and

winter solstice The winter solstice, also called the hibernal solstice, occurs when either of Earth's poles reaches its maximum tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern and Southern). For that hemisphere, the winter ...

. The sunset alignments occur around May 28 and July 13. The sunrise alignments occur around December 5 and January 8. Manhattan is a particularly remarkable place to view a phenomenon of this kind, due to its extensive

urban canyon An urban canyon (also known as a street canyon) is a place where the street is flanked by buildings on both sides creating a canyon-like environment, evolved etymologically from the Canyon of Heroes in Manhattan. Such human-built canyons are made ...

s and its rectilinear street grid that is rotated 29° clockwise from true east–west. Excellent places for viewing Manhattanhenge include 14th, 23rd, 34th, 42nd, and 57th Streets.

Explanation and details

The term ''Manhattanhenge'' is a reference to Stonehenge, a prehistoric monument located in

Wiltshire Wiltshire (; abbreviated Wilts) is a historic and ceremonial county in South West England with an area of . It is landlocked and borders the counties of Dorset to the southwest, Somerset to the west, Hampshire to the southeast, Gloucestershire ...

, 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 Heel Stone is a single large block of sarsen stone standing within the Avenue outside the entrance of the Stonehenge earthwork in Wiltshire, England. In section it is sub-rectangular, with a minimum thickness of , rising to a tapered to ...

". The phenomenon (but not the term "Manhattanhenge") was described by

, an astrophysicist at the American Museum of Natural History and a native New Yorker in 1997 in the magazine '' Natural History.'' In a later interview, Tyson stated that he coined the term, and that it was inspired by a childhood visit to Stonehenge on an expedition headed by

Gerald Hawkins Gerald Stanley Hawkins (20 April 1928– 26 May 2003) was a British-born American astronomer and author noted for his work in the field of archaeoastronomy. A professor and chair of the astronomy department at Boston University in the Uni ...

, an astronomer who was the first to propose Stonehenge's purpose as an ancient astronomical observatory used to predict movements of sun and stars, as outlined in his 1965 book ''Stonehenge Decoded''. According to Tyson, In accordance with the

Commissioners' Plan of 1811 The Commissioners' Plan of 1811 was the original design for the streets of Manhattan above Houston Street and below 155th Street, which put in place the rectangular grid plan of streets and lots that has defined Manhattan on its march uptown ...

, the street grid for most of Manhattan is rotated 29° clockwise from true east-west. Thus, when the

azimuth An azimuth (; from ar, اَلسُّمُوت, as-sumūt, the directions) is an angular measurement in a spherical coordinate system. More specifically, it is the horizontal angle from a cardinal direction, most commonly north. Mathematical ...

for sunset is 299° (i.e., 29° north of due West), the sunset aligns with the streets on that grid. This rectilinear grid design runs from north of

Houston Street Houston Street ( ) is a major east–west thoroughfare in Lower Manhattan in New York City. It runs the full width of the island of Manhattan, from FDR Drive along the East River in the east to the West Side Highway along the Hudson River i ...

in Lower Manhattan to south of 155th Street (Manhattan) in Upper Manhattan. A more impressive visual spectacle, and the one commonly referred to as Manhattanhenge, occurs a couple of days after the first such date of the year, and a couple of days before the second date, when a pedestrian looking down the centerline of the street westward toward New Jersey can see the full solar disk slightly above the horizon and in between the profiles of the buildings. The date shifts are due to the sunset time being when the last of the sun just disappears below the horizon. The precise dates of Manhattanhenge depend on the date of the summer solstice, which varies from year to year, but remains close to June 21. In 2014, the "full sun" Manhattanhenge occurred on May 30 at 8:18 p.m., and on July 11 at 8:24 p.m. Tyson, Neil deGrasse
"Manhattanhenge"
on the

Hayden Planetarium The Rose Center for Earth and Space is a part of the American Museum of Natural History in New York City. The Center's complete name is The Frederick Phineas and Sandra Priest Rose Center for Earth and Space. The main entrance is located on the n ...

website The event has attracted increasing attention in recent years. The dates on which sunrise aligns with the streets on the Manhattan grid are evenly spaced around the

and correspond approximately to December 5 and January 8.

Occurrences

Manhattanhenge creating beautiful colors on West 42nd Street

Manhattanhenge Workers head out of Penn Station into the sunrise on 2020-01-21 on W 32nd St IMG 7727 FRD

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.

Related phenomena in other cities

The same phenomenon happens in other cities with a uniform street grid and an unobstructed view of the horizon. If the streets on the grid were rigorously north-south and east-west, then both sunrise and sunset would be aligned on the days of the vernal and autumnal

equinox A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and se ...

es (which occur around March 20 and September 23 respectively). In

Baltimore Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...

, for instance, sunrise aligns on March 25 and September 18 and sunset on March 12 and September 29. In Chicago, the setting sun lines up with the grid system on March 20 and September 25, a phenomenon dubbed ''Chicagohenge''. In

Toronto Toronto ( ; or ) is the capital city of the Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the most populous city in Canada and the fourth most populous city in North America. The city is the anch ...

, the setting sun lines up with the east–west streets on February 16 and October 25, a phenomenon now known locally as ''Torontohenge''. In

Montreal Montreal ( ; officially Montréal, ) is the second-most populous city in Canada and most populous city in the Canadian province of Quebec. Founded in 1642 as '' Ville-Marie'', or "City of Mary", it is named after Mount Royal, the triple ...

, there is a ''Montrealhenge'' each year around June 12. When the architects designing the city centre of Milton Keynes, in the United Kingdom, discovered that its main street almost framed the rising sun on Midsummer Day and the setting sun on Midwinter 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. In

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. As part of the Boston metropolitan area, the cities population of the 2020 U.S. census was 118,403, making it the fourth most populous city in the state, behind Boston ...

, ''MIThenge'' occurs about January 29 and November 11, when the setting sun may be seen across the length of the "

Infinite Corridor The Infinite Corridor 203 pp. is a hallway that runs through the main buildings of the Massachusetts Institute of Technology, specifically parts of the buildings numbered 7, 3, 10, 4, and 8 (from west to east). Twice a year, in mid-November a ...

", at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

References

External links

Media

Flickr photos tagged with ManhattanhengeVideo interpretation of ManhattanhengeVideo on Science Friday website
'' NOVA scienceNOW'', first broadcast September 14, 2006

Discussion

Hayden Planetarium discussion

Images and maps

Manhattanhenge images on Yahoo! news
July 12, 2011
Interactive map showing Manhattanhenge visibility by time of year
{{Portal bar, New York City, Society, Astronomy, Stars, Solar System, Science Astronomical events of the Solar System Culture of Manhattan 2000s neologisms May events July events Geography of Manhattan Neil deGrasse Tyson Solar alignment Solar phenomena