• Manhattanhenge's sunset show wows New Yorkers

    Julio Cortez / AP

    Photographers aim their cameras as the sun sets through the buildings on 42nd Street in Manhattan during a phenomenon known as Manhattanhenge on July 11, 2012. Manhattanhenge, sometimes known as the Manhattan Solstice, occurs when the setting sun aligns with east-to-west streets of the main street grid.

    By Alan Boyle, Science Editor, NBC News


    Tonight's showing of New York's hometown celestial alignment, known as Manhattanhenge, was a spectacular success that more than made up for the washout in May.

    Some of Manhattan's best-known east-west streets — 42nd Street, for instance — were filled with the glow of the setting sun at 8:24 p.m. ET. They were also filled with crowds straining to snap pictures.

    "When did Manhattanhenge turn into Woodstock?" Brooklyn resident Joe Raskin asked in a Twitter update.

    Julio Cortez / AP

    People stand in the middle of 42nd Street as the sun nears the horizon on July 11, 2012.

    Andy Dallos / The Rachel Maddow Show

    Andy Dallos, a producer for "The Rachel Maddow Show" on MSNBC, documented Manhattanhenge in a series of shots snapped from West 50th Street. Check out The Maddow Blog for more of Dallos' photos.

    Manhattanhenge occurs when Earth's tilt is just right to have the sun right on the horizon, in line with the orientation of the street grid. That happens twice a year, generally in late May and mid-July. This year, the best viewing times were on May 29 and 30, and again on July 11 and 12. May's opportunity wasn't the greatest, due to clouds and rain. This week, however, the skies have been sunnier, and so have the dispositions of the New Yorkers hoping to get a good view.

    "A Manhattanhenge sun sets, leaving a luminous glow in its wake," photographer Inga Sarda-Sorensen wrote in an oft-retweeted Twitter update.

    The best news for New Yorkers is that the show replays Thursday at 8:25 p.m. ET, when the sun can be seen as a half-disk sitting on the western horizon. (Remember, don't gaze at the sun for any length of time with unshielded eyes.) Here's a quick viewing guide from Life's Little Mysteries.

    Did you get a great picture tonight? Share it with us and other msnbc.com users via our FirstPerson upload page.

    Update for 3:25 p.m. ET July 12: Thanks, readers, for coming through with some great shots. If you're in Manhattan, you've got another shot at the 'Henge at sunset. To whet your appetite, check out these FirstPerson pictures:

    Submitted by Chaitanya Kapadia / UGC

    Here's what Chaitanya Kapadia says about this picture: "I had set up on a nice spot right in the middle of 34th Street, between the double yellow lines with a few photographers wanting to get the Empire State Building in my shot. However, I should have anticipated photographers to just swarm the streets when the sun lined up with the grid. Minutes later, the police drove down the middle of the road, getting everyone out, which only meant stepping to the side until they passed you, and then right back. Took this using three exposures hand-held."

    Submitted by Anne Torres / UGC

    Anne Torres captured Manhattanhenge from Tudor City on July 11. During the setup for the shot, Torres wrote this report: "Spectators begin staking their spots right in the middle of East 42nd Street a little before 8 p.m. Several people behind me who were positioned up on Tudor City can be heard muttering, 'Crazy New Yorkers.'"

    Submitted by Paolo Palmero / UGC

    FirstPerson contributor Paolo Palmero sent in this perfect aligned shot of the sun setting between Manhattan's skyscrapers on July 11.


    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • New Yorkers get second chance to see monumental Manhattanhenge

    Mike Segar / Reuters file

    The sun shines down 42nd Street below the landmark Chrysler Building at sunset on July 12, 2009, during Manhattanhenge.

    By Alan Boyle, Science Editor, NBC News

    The first night of this year's Manhattanhenge season was a washout, due to cloudy weather, but there's another chance to see the sunset turn the streets of New York aglow tonight.

    Manhattanhenge refers to the perfectly placed alignment of the setting sun amid the canyons of midtown Manhattan's east-west streets. The phenomenon, sometimes known as the Manhattan solstice, occurs every year around Memorial Day and major-league baseball's All-Star break.

    The Hayden Planetarium's director, Neil DeGrasse Tyson, says future archaeologists might well conclude that these spots on the calendar marked important rites of summer for New Yorkers. (And they wouldn't be far wrong.)

    Tyson's the one who came up with the term "Manhattanhenge." Think of it as a modern-day, unintentional version of Stonehenge, with New York skyscrapers standing in for the stones of the 5,000-year-old monument in England.

    Stonehenge was constructed to have its stones line up with the rays of the sun on important astronomical dates such as the summer solstice. Manhattan's street grid, however, doesn't line up with the solstice or the equinox. The relevant streets, which reflect the Commissioner's Plan of 1811, are offset 29 degrees from east and west. That would spoil the sunset view on an equinox or a solstice — but on the proper dates, the sun reaches the cleft between skyscrapers just in time to set the streets aglow.

    This year's first opportunity for seeing Manhattanhenge's glory came Tuesday night at 8:17 p.m. ET. Under ideal conditions, a pretty half-setting sun could have been seen centered in the gap between the buildings. Unfortunately, conditions were not ideal. In disappointed Twitter tweets, the sight quickly came to be termed "Cloudhenge."

    Andrew Dallos via Twitpic

    Andrew Dallos' picture of Manhattanhenge, snapped at sunset on Tuesday from 42nd Street, provides a typical view of "Cloudhenge."

    "A cloudy and stormy night, so no sun," reported Andrew Dallos, a producer for "The Rachel Maddow Show" on MSNBC who camped out on 42nd Street.

    Tonight, on Wednesday night, New Yorkers could get a chance to see the sun's full disk just touching the horizon in the gap at 8:16 p.m. ET. It all depends on the weather: The current forecast calls for partly cloudy skies with a slight chance of thunderstorms — which at least sounds more promising than last night's weather.

    Even if tonight's opportunity is clouded out, there'll be a Manhattanhenge replay after the summer solstice, with a full-sun viewing at 8:24 p.m. on July 11 and a half-sun opportunity at 8:25 p.m. July 12.

    To enhance your Manhattanhenge viewing experience, Tyson suggests positioning yourself as far east as possible, while still making sure you can see New Jersey when you look west across the avenues. "Clear cross streets include 14th, 23rd, 34th, 42nd, 57th and several streets adjacent to them," he writes in his viewing guide. "The Empire State Building and the Chrysler Building render 34th Street and 42nd Street especially striking vistas."

    A time-lapse view of Manhattanhenge from 2011.

    Thanks in part to Tyson's efforts, Manhattanhenge is the best-known of the modern-day monumental alignments. The clear prospect to the west between New York's towering buildings makes for a nearly unbeatable scene. But other locales have their own "Henge" dates, due to the unintentional effects of a street-grid layout or an architectural feature. Here's a sampling:

    Baltimorehenge: The sun lines up with downtown Baltimore's street grid for sunrise on Sept. 18 and March 25, and for sunset on Sept. 29 and March 12. The Baltimore Sun's Frank Roylance explains it all for you.

    Phillyhenge: The sunrise moments have come around March 1 and Oct. 11, and sunset alignments are around April 4 and Sept. 5. Precise dates vary from year to year. The Photographer's Ephemeris helps you find the proper lineup.

    Torontohenge: The sun lines up with Toronto's street grid for sunrise on April 17-18 and Aug. 23-24, and for sunset on Feb. 15-16 and Oct. 23-24. This entry from Torontopedia helps you figure it out.

    Other urban "Henges": If downtown streets line up more precisely with a true east-west axis — as they do in Chicago, Washington and Portland, Maine, for example — the "Henge" moments come around the March 20-21 spring equinox and the Sept. 21-22 autumn equinox.

    MIT-Henge in Cambridge, Mass: The rays of the setting sun light up the "Infinite Corridor" at the Massachusetts Institute of Technology in late January and during the second week of November. This video fills in the details.

    Do you know of other monumental alignments? Clue in the rest of us by leaving a comment below.

    More celestial alignments:

    This is an updated version of an item originally published on May 29.

    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.