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 16 hours after perigee (on June 8, 1937, at 4:30 UTC), the Moon's apparent diameter was larger.

The American expedition was organized by the National Geographic Society and assisted by the United States Navy.

This total solar eclipse was memorable for three reasons: first, the duration of totality was particularly long with the longest point in eastern Pacific exceeding 7 minutes; second, despite being in the tropics, weather was good for all observation sites; third, broadcasts were made through radio before, during and after the eclipse through long distances so people could hear the details.

This eclipse is a part of Saros series 136, repeating every 18 years, 11 days, and containing 71 events.

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