What causes the appearance of Baily's Beads during a solar eclipse?

Baily's Beads appear when the Moon’s uneven edge lets tiny slivers of the Sun’s bright disk peek through valleys and mountains on the Moon’s surface just before the eclipse’s total phase. The Moon’s silhouette is not a perfect circle; its topography creates gaps that let sunlight escape in a bead‑like pattern. As the Moon moves across the Sun, these gaps appear as bright points that flash on and off. For example, when the Moon’s crater rim is between us and the Sun, a small bead of light shines through the crater opening, producing a “bloom” of light that looks like beads on a necklace. This effect is most noticeable when the Sun’s rim is still visible but almost hidden by the Moon.