This total solar eclipse is the first within the United States since the eclipse of July 11, 1991 when the path of totality crossed over Hawaii and the great observatories of Mauna Kea. The previous total solar eclipse over the coterminus 48 states was the eclipse of February 26, 1979 which passed over the northwestern states of Oregon, Washingon, Idaho, and Montana. The August 21, 2017 eclipse sweeps across the United States from Oregon to South Carolina, allowing almost every person in the 48 states to reach totality within a day’s drive.
These maps apply eclipse calculations by Bill Kramer with eclipse timing corrections for the precise profile of the moon. The lunar profile was derived from laser altimeter data from the Japanese Kaguya lunar orbiter by Dave Herald. The careful map reader will note that the isodurations (lines of equal eclipse duration) are not symmetric around the central line of eclipse; this is due to the corrections for the actual lunar profile.
Applying corrections for the lunar profile, the location which will enjoy the very longest duration of eclipse will be in southern Illinois at 89.4030 degrees west longitude, 37.69335 degrees north latitude with a duration of 2 minutes, 41.7 seconds. The nearest sizable town is Murphysboro, Illinois, about 8 kilometers to the northeast.
