When is Manhattanhenge 2008?

Manhattanhenge occurs at sunset, 8:18PM EDT, on the 28 May at an azimuth of nearly 300°. By definition, sunset occurs when the Sun's trailing edge descends below our horizon , so one wants to arrive prior to 8:18PM to watch it entirety. 300° azimuth is 30° greater, or more northern, than cardinal point west, yet it corresponds to orientation of the cross streets of the Manhattan grid. Cross streets align along azimuths 120° on the east and 300° on the west, as depicted in the illustration below.



The Sun has an angular measurement around a half of a degree. The angular measurement of the street canyon from where I observed that sunset is slightly greater than my pinky held at arm's length, about a degree to a degree and one half ( 1° ~ 1.5°). In the schematic below the solar is disk is larger and brighter because of glare, the actual solar disk when observed through a solar filter is smaller, where nearly 3 solar disks could fit between the buildings.

At this time of the year the Sun lies on the ecliptic within the boundaries of the constellation Taurus. This is a section of the ecliptic where its angle with respect to the horizon is nearly perpendicular. In other words, the Sun sets on a steep angle so one can watch the sun set with more of a vertical drop rather than being carried across a shallow path.

If you miss the event or weather is afoul, one can still observe this on days leading up to or just past with the same effect. A list of the days , time of sunset and azimuth is provided below. Choose a cross street where you there is an unobstructed view to the western horizon. Any of the major cross streets work, like 23rd, 34th, 42nd, and 57th.

Don't forget to look behind you, your shadow is at its longest length, like the cone of night.

26 May, 8:16PM EDT --- 299° 29'
27 May, 8:17PM EDT --- 299° 43'
28 May, 8:18PM EDT --- 299° 56'
29 May, 8:19PM EDT --- 300° 09'
30 May, 8:19PM EDT --- 300° 21'

Update: Manhattanhenge on 28 May 2007

20070528.2017 - Sunset for Manhattanhenge

(photo from last year, read about it here)

There is correspondence bouncing around Team TotL that Manhattanhenge May 2007 is tonight. Charlie referenced the Manhattan-henge article on the Hayden Planetarium website. I referenced a message from their email newsletter service star-struck. This article provides the following sunset dates for Manhattan-henge around these dates:

• May 28 at 8:10 PM
• July 11 at 8:27 PM

It appears that most will observe the event tonight, especially since I heard this date more than once from others. I'll most likely join others at 34th & Park Ave. Arriving by 8pm will be adequate to watch the sun set into New Jersey, requiring at least 15 minutes before sunset. Sunset is the time when the sun's upper limb descends below the horizon. That is the Sun has disappeared from our view. To observe the Manhattanhange, one begins watching prior to sunset.

It has been a lot of fun in the past and the energy created by the interested persons is uplifting. In spite of its small scale, it is one of those events that brings New Yorkers together in harmony. Where else can one see when a traffic light change for red and a hundred or more people rush the center line flashing away?

Lastly, listen to the caution that many will voice: Don't look at the Sun directly as it is harmful and dangerous to one's eyesight.

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Want to know more about sunset?
U.S. Naval Observatory
- Rise, Set, and Twilight Definitions

- Complete Sun and Moon Data for One Day calculator

Wikipedia
- Sunset

Fox Lane High School
- LENGTH OF DAY ON THE EQUINOX