(NEXSTAR) – If you live at the edge of the path of totality, you may not want to trust your map of the 2024 total solar eclipse.
A new map by eclipse calculator John Irwin claims that the path of totality, roughly 115 miles wide, is actually slightly narrower than previously thought, meaning that people along the edges might not have the eclipse experience they were expecting.
“By accounting for the topography of both the moon and the Earth, precise eclipse prediction has brought new attention to a tiny but real uncertainty about the size of the Sun,” NASA Heliophysics Editorial Lead Abbey Interrante told Nexstar in an email.
The larger the sun is in the calculation, the smaller the shadow produced by the moon.
Luca Quaglia, a collaborator of Irwin’s, explained that in eclipse computations the value of the size of the sun has been left up to the eclipse computer. Since the late 1800s, eclipse calculations have commonly used a solar radius of 959.63 arc seconds (which is one 3,600th of a degree).
“Measurements and observations in the last decade have demonstrated that this value is slightly too small,” Quaglia told Forbes. Irwin’s map uses a solar radius of 959.95 arc seconds, which trims about 2,000 feet from the edges of the path of totality as it is currently shown on maps, meaning already-borderline cities like Rome, New York; Fort Wayne, Indiana; Denton, Texas; and Effingham, Illinois; will be further away from a view of totality than previously thought.
To be clear, people planning on traveling into the path of totality to watch the celestial phenomenon don’t have to double check their maps.
“This difference would only affect cities on the very edge of the path of totality, where blanket predictions are difficult regardless – a few city blocks one way or the other could mean 20, 10, or 0 seconds of totality,” Interrante told Nexstar. “Traveling towards the center of the path of totality – even a mile or two – will quickly increase the length of totality that people can see.”
Interrante told Nexstar that NASA’s eclipse predictions have not changed, but the sun’s radius will be the subject of a SunSketcher research project during the April 8 eclipse.
The total solar eclipse will first be visible in the United States from Texas, after which the path moves through Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine.
Slivers of both Tennessee and Michigan also fall into the path of totality.
If you plan on watching the eclipse, be sure to follow these safety tips and, if you’re using eclipse glasses, make sure they’re the correct ones.
After April 8, you won’t have another chance to watch a total solar eclipse from the contiguous United States until Aug. 23, 2044.
