A total solar eclipse occurred on July 29, 1878. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. This eclipse was visible at sunrise at a path across northeastern Asia and passed across Alaska, western Canada, and the United States from Wyoming through Texas.