Day of Black Sun


 * This article is about the event. For the episodes, see The Day of Black Sun, Part 1: The Invasion and The Day of Black Sun, Part 2: The Eclipse. For the battle, see Invasion of the Fire Nation.



The Day of Black Sun refers to the recurring day of a complete solar eclipse, where the sun is entirely blocked out by the moon, rendering Firebenders powerless. There have only been two known Days of Black Sun in recorded history.

History
Little is known of the first recorded Day of Black Sun, except that it was considered "the darkest day in Fire Nation history". In one of the Avatar Extras pop-ups, it was revealed that the date of black sun, indicated where Sokka found the paper, was the ninth day of the seventh month, or July 9.

On the second Day of Black Sun, the Fire Nation Capital was invaded, with the objective of defeating the Fire Lord, thus ending the century-long war. The Fire Nation was however already informed of the invasion, as Azula, Mai, and Ty Lee chanced across early invasion plans during the time they spent disguised as the Kyoshi Warriors in Ba Sing Se. The 52nd Earth King had informed them unknowingly, believing them to be of the Earth Kingdom allies, the Kyoshi Warriors, and for his mistake, the Fire Nation was able to anticipate and prepare for the invasion. The invasion force managed to reach the Royal Palace, but were unable to escape after the eclipse ended. The invasion force was taken prisoner while the younger members fled on Appa.

The Day of Black Sun was not a total failure, however. It was revealed that during the eclipse, King Bumi found "the right moment to strike" and single-handedly liberated the city of Omashu, thus beginning the eventual liberation of the Fire Nation occupied parts of the Earth Kingdom.

Trivia

 * In the real world, total eclipses have a similar duration time as portrayed in the series. However, the fact that people in the Fire Nation and Earth Kingdom could both see a total eclipse at the same time is quite fictional. The area on the Earth where the moon completely eclipses the sun is very, very small (roughly a few miles in diameter) compared to the area where the sun is only partially eclipsed, which can be as large as an entire nation. That is, unless, the planet where the Avatar universe is located in is a lot smaller than Earth, and/or the moon is closer to the earth, or larger in proportion (making the moon's large coverage during an eclipse plausible).
 * Solar eclipses have no known effect on Waterbending. However, during a solar eclipse, the moon is actually in the new moon phase, making it reasonable to assume that Waterbenders would not experience the enhancing effects that the full moon provides.
 * A solar eclipse is the only natural event known to leave Firebenders powerless.
 * A complete solar eclipse did in fact occur over parts of North America on July 9, 1945, the month and day of the first Day of Black Sun.
 * The total eclipse lasts for only eight minutes.
 * The recent eclipse in The World of Avatar was on the 1st day of the 8th month.