Diagram showing the path of the North American Eclipse, due on 21 August 2017. A partial eclipse will be visible from every state in the USA, with totality visible from the entire country in a narrow swath running straight through its centre (blue). The last time this happened was on 8 June 1918, 99 years earlier. This eclipse is set to be a good one, already being dubbed the Great American Eclipse, with totality lasting for a maximum of 2 minutes and 41.6 seconds in Illinois. A solar eclipse occurs when the Moon passes directly between the Earth and the Sun, blocking the disc of the Sun in the sky. The labels indicate the time of totality (Universal Time or UT), the duration of totality at those times, and the shaded black circles represent the degree of partiality north and south of the line of totality of partiality north and south of the line of totality.