What it looks like is similar to what happens on the summer solstice at Stonehenge: As the sun shrinks below the horizon, its circular outline fits perfectly in the center of the tall towers lining the streets and avenues of the Big Apple.
Neil deGrasse Tyson, director of the Hayden Planetarium at the American Museum of Natural History and host of the wildly popular television series "Cosmos: A Spacetime Odyssey," described it as "a rare and beautiful sight."
Because of its similarity to what happens at Stonehenge, the event is appropriately called Manhattanhenge. And it's a big deal on Instagram, so get your cameras ready.
The event will take place Friday and Saturday at sunset, which is at about 8:12 pm ET.
DeGrasse Tyson says that you need perfectly straight streets to see the phenomenon and not to be fooled by some streets like Sunrise Highway.
"True, some municipalities have streets named for the sun, like Sunrise Highway on Long Island and the Sunset Strip in Los Angeles. But these roads are not perfectly straight. And the few times a year when the Sun aligns with one of their stretches of road, all you get is stalled traffic solar glare temporarily blinds drivers."
If you want to get a spectacular view of this year's Manhattanhenge, the best cross streets include 14th, 23rd, 34th, 42nd, and 57th. Also, the Chrysler building on 42nd and the Empire State Building on 34th are ideal vantage points.
Whatever location you choose, arrive 30 minutes prior to 8:12 pm. If you miss it or the weather doesn't cooperate, don't fret: Manhattanhenge occurs again on July 12 and 13 at 8:20 pm.
Here are some incredible pictures of the Manhattanhenge of former years: