An annular solar eclipse occurred on August 20, 1952. 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. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Annularity was visible from Peru including the capital city Lima, northeastern Chile, Bolivia including the constitutional capital Sucre and seat of government La Paz, Argentina, Paraguay, southern Brazil and Uruguay.