Data sources and method

Eclipse catalogue

Dates, types, times of greatest eclipse, magnitudes, Saros numbers, durations and visibility regions come from the NASA Eclipse Web Site by Fred Espenak (NASA’s Goddard Space Flight Center): Solar Eclipses 2021–2030 and Lunar Eclipses 2021–2030.

Paths

The map bands are drawn from NASA’s path tables, which list the northern limit, southern limit and centre line every two minutes of Universal Time. Coastlines are Natural Earth 1:110m via the world-atlas package.

Local times

For any place, the calculator evaluates NASA’s polynomial Besselian elements for that eclipse and solves for the four contacts and the moment of maximum, following the method in the Explanatory Supplement to the Astronomical Almanac. It reproduces NASA’s central durations to within about a second. It uses a smooth lunar limb, so real contact times near the path edges can differ by a few seconds.

Lunar eclipse contact times are derived from NASA’s greatest-eclipse time and phase durations (Terrestrial Dynamical Time converted to UT with ΔT ≈ 72 s), accurate to about a minute.

Eye safety

NASA eclipse safety and the American Astronomical Society Solar Eclipse Task Force.

Photography

Exposure values follow F. Espenak’s Solar Eclipse Exposure Guide published on the NASA eclipse site.

Eclipse predictions by Fred Espenak, NASA’s GSFC. Eclipse Journey is independent and not affiliated with NASA.