Milky Seas Effect

A rare phenomenon in which a vast expanse of ocean, sometimes tens of thousands of square kilometers, glows with a steady, uniform white or pale blue light overnight, visible even from orbiting satellites. The effect is attributed to enormous, dense colonies of bioluminescent bacteria, most likely Vibrio harveyi, that coat the sea surface, though it remains difficult to study directly because sightings are unpredictable and mostly reported by passing ships in remote stretches of the Indian Ocean and waters near Indonesia.