The interactive eclipse map

How to read the map

The shaded band is the path of totality — the track of the Moon’s umbral shadow across the Earth’s surface. Stand inside it and the Sun disappears completely. Stand one kilometre outside it and it does not, no matter how close you feel.

• Gold shading marks how long totality lasts. The narrow bright core along the middle is where you get six minutes or more; the duller outer bands fall away towards the edges.
• The dashed turquoise line is the central line, where totality lasts longest at each moment.
• The thin gold edges are the northern and southern limits. Crossing one of them is the difference between a total eclipse and a very deep partial one.
• Gold dots are places inside the path; grey dots are places that miss it. Click either for a guide.

What the calculator actually does

When you click, the page evaluates the polynomial Besselian elements published by NASA/GSFC for this eclipse, in your browser, for the exact coordinates you picked. It solves for the instants of first, second, third and fourth contact, the Sun’s altitude and azimuth, the eclipse magnitude and the fraction of the solar disc covered. It is the same calculation the published tables use — our implementation reproduces NASA’s central-line durations to within about a tenth of a second.