Twice a year, New Yorkers gather for one of the two annual spectacles of Manhattanhenge. The term was coined by Astrophysicist Neil deGrasse Tyson in 1977, the name is a reference to Stonehenge. At Stonehenge, the sun aligns with concentric circles of vertical stones on each of the solstices. In Manhattanhenge, the sunset aligns perfectly with Manhattan's skyscrapers, which were built on the city's street grid layout. The event tends to draw thousands of onlookers, tourists and locals alike, who wish to capture the perfect image. Manhattanhenge happens every year in May and July, for two nights each. It happens roughly three weeks before and three weeks after the summer solstice.