Tyson has written a number of popular books on astrophysics. In 1995, he began to write the "Universe" column for Natural History magazine. In a column Tyson wrote for a special edition of the magazine, called "City of Stars", in 2002, he popularized the term " Manhattanhenge " to describe the two days annually on which the evening sun aligns with the street grid in Manhattan, making the sunset visible along unobstructed side streets. He had coined the term in 1996, inspired by how the phenomenon recalls the sun's solstice alignment with the Stonehenge monument in England. Tyson's column also influenced his work as a professor with The Great Courses.