Click here for the Jupiter and Venus Conjunction Star Party

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This weekend, and the second weekend in July, “Manhattanhenge” once again returns to New York City.

http://www.haydenplanetarium.org/resources/starstruck/manhattanhenge

Manhattanhenge 2009

Half Sun on the grid:
Saturday, May 30 . 8:17 P.M. EDT
Sunday, July 12 . 8:25 P.M. EDT

Full Sun on the grid:
Sunday, May 31 . 8:17 P.M. EDT
Saturday, July 11 . 8:25 P.M. EDT

As you may know, Manhattanhenge takes place on two consecutive days, twice a year, when the setting Sun aligns precisely with the Manhattan street grid, creating radiant sunsets that burst across our brick and steel canyons, simultaneously illuminating both the north and south sides of every street. A rare and beautiful sight.

Unnoticed by many, the sunset point actually creeps day to day along the horizon: northward until the first day of summer, then returning southward until the first day of winter. In spite of what pop-culture tells you, the Sun rises due east and sets due west only twice per year - the first day of spring and of autumn. Every other day, the Sun rises and sets elsewhere on the horizon.

While we are on the subject, when viewed from all latitudes north of the Tropic of Cancer (23.5 degrees north latitude), the Sun always rises at an angle up and to the right, and sets and an angle down and to the right. That’s how you can spot a faked sunrise in a movie: it moves up and to the left. Filmmakers are not typically awake in the morning hours to film an actual sunrise, so they film a sunset instead, and then time-reverse it, thinking nobody will notice.

The consecutive days for Manhattanhenge identify when half the Sun’s disc and when the entire Sun’s disc is setting on the grid. If the Sun were to set perpendicular to the horizon then these would be the same day. But since the Sun’s path angles down and to the right, and shifts slightly from one day to the next, we get two days of Manhattanhenge, a half-sun sunset (my personal favorite for photographs) and full-sun sunset.

To learn more about Dr. Tyson, visit his website here: http://research.amnh.org/users/tyson

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About Jason Kendall

I am the NASA/JPL Solar System Ambassador for New York City. I hold a Master of Science in Astronomy from New Mexico State University and am currently adjunct faculty at William Paterson University. I have led numerous "starwatching parties" and astronomy events in New York City, New Mexico, Minnesota and Texas. It all started way back in the fourth grade by the encouragement of two noted astronomers, Charles Schweighauser and Bart Bok. I saw Saturn through Charlie's telescope at then Sangamon State University on a clear Illinois night, and Bart encouraged me under those stars to study hard to come visit him at Kitt Peak National Observatory. I finally did make it down there about a decade after Bart passed away, and I found the favorite spots in Tucson, Arizona, where Bart and his wife Priscilla would spend when they were not gazing at the stars. Bart and his wife were pioneers in the study of the Milky Way, and their studies of the starforming regions called Bok Globules. It's even in my family. My great-grandfather was a Midwestern minister who used to preach his sermons out under the dark, cloudless nights. He always believed that getting out and experiencing the wonders of the natural world was a central part of being human. My family has always been inspired by his words: "We look up to look within." I hope that you'll join me under the stars or at one of my talks.

Come see what's up in the sky!

Jason Kendall
NASA/JPL Solar System Ambassador to New York City

The Inwood Astronomy Project is thankful for the support of the NASA/JPL Solar System Ambassadors Program, the New York City Department of Parks and Recreation, the New York Public Library, the International Year of Astronomy and the Amateur Astronomers Association of New York


We look up to look within