A total solar eclipse occurred at the Moon's ascending node of orbit on Tuesday, October 1, 1940,[1] with a magnitude of 1.0645.

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.

Occurring about 4 hours before perigee (on October 1, 1940, at 17:00 UTC), the Moon's apparent diameter was larger.

Other scientists went to the edge of the path of totality to study the spectral lines of the solar chromosphere.

[6] The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles.

Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee).