(CNN) — It's a magical, fleeting moment that can leave viewers awestruck: The sun perfectly aligns through spaces between carefully constructed monolithic structures to cast an amazing beam of light.
No, we're not talking about the ancient site of Stonehenge in the countryside of England.
This is the modern version -- "Manhattanhenge" in the very modern and urban New York City. Whether you live there or just happen to be in New York for travel, you could be in for a real treat.
Light from the sunsets shoots down roads running east to west with no blockage from the borough's famous skyscrapers on Friday and Saturday (July 12 and 13, 2019). You might want to seek out a good spot about a half hour before sunset.
Be positioned well when the time comes, as the effect lasts only a few minutes.
Friday saw a full sun on the grid at 8:20 p.m. You'll see half of the sun's orb peeking up at 8:21 p.m. Saturday.
In New York, the weather forecast for Saturday is sunny skies and a temperature in the low 80s at sunset.
What causes it?
The sun sets on the horizon across 42nd Street. The effect only lasts a few minutes, so find a spot before sunset.
Timothy A. Clary/AFP/Getty Images
You can thank Manhattan's easy-to-use grid system, which dates back to the early 1800s, for the effect. This happy alignment starts at Houston Street and runs up to just south of 155th Street. If Manhattan's street grid was perfectly aligned along north-south lines, then Manhattanhenge would coincide with the equinoxes. But Manhattan's layout is rotated 30 degrees east from geographic north, shifting the days of alignment to late May and mid-July.
Where does the name come from?
The term "Manhattanhenge" is popularly attributed to astrophysicist Neil deGrasse Tyson, who word-played off Britain's Stonehenge. That ancient structure highlights the sun in similar fashion during the winter and summer solstices.
Where to see it?
14th Street is a popular gathering spot for Manhattanhenge.
Mario Tama/Getty Images
"For best effect, position yourself as far east in Manhattan as possible. But ensure that when you look west across the avenues, you can still see New Jersey." He lists the following streets as particularly good ones since they are wider:
-- 14th Street
-- 23rd Street
-- 34th Street
-- 42nd Street
-- 57th Street