In New York City, when the setting sun aligns perfectly with Manhattan's grid-patterned streets, it creates a picturesque effect where the north and south sides of the city's cross streets are basked in the sun's light.
The phenomenon, dubbed "Manhattanhenge," occurs twice a year with the full sun, and twice a year with the half sun, depending on weather conditions. The dates vary each year, but they typically fall in May and July. In 2015, it occurs on May 29, May 30, July 12 and July 13. (The half sun will be visible along the grid-patterened streets on May 29 and July 13, and the full sun will be visible on May 30 and July 12.)
During the full Manhattanhenge, as the setting sun lines up with the city streets, the entire orb appears on the horizon. With the half sunsets, as the name implies, half of the sun appears above the horizon, and the other half below.
How to see Manhattanhenge
The most spectacular Manhattanhenge displays occur at sunset, but spectators are advised to head outside about 30 minutes before to watch as the sun descends in the sky. On May 29 and May 30, sunset in New York City is at 8:12 p.m. EDT. On July 12, it's at 8:20 p.m. EDT, and on July 13, the sun will set at 8:21 p.m. EDT.
Astrophysicist Neil deGrasse Tyson, director of the American Museum of Natural History's Hayden Planetarium, coined the name "Manhattanhenge" in 2001, and is credited with increasing the event's popularity.
"For best effect, position yourself as far east in Manhattan as possible," Tyson wrote in a blog post on the Hayden Planetarium's website. "But ensure that when you look west across the avenues you can still see New Jersey."
Tyson suggests picking one of the wider cross streets to view Manhattanhenge, including 14th, 23rd, 34th, 42nd and 57th. Many of the streets immediately adjacent to these ones also offer nice places to watch the spectacle.
"The Empire State Building and the Chrysler Building render 34th Street and 42nd Street especially striking vistas," Tyson said. [Manhattanhenge Gallery: Photos of NYC's Special Sunsets]
Beyond New York City
The nickname Manhattanhenge is derived from Stonehenge, a prehistoric monument that can be found north of the modern-day city of Salisbury, England. Once a year, the sunrise is perfectly aligned with the stone columns that make up this horseshoe-shaped megalith, which archaeologists believe was built around 2,500 B.C.
Still, New York City is not the only place to experience these types of solstices. Other cities with straight east-west grid-patterned streets enjoy these dazzling sunsets as well, including Chicago and Baltimore in the United States, and Toronto in Canada.