Satellites Spot Oceans Aglow With Trillions of Organisms

A new generation of detectors let scientists identify a dozen large episodes of bioluminescence, one a hundred times larger than Manhattan — and that’s the smallest.

The ocean has always glowed. The Greeks and Romans knew of luminous sea creatures as well as the more general phenomenon of seawater that can light up in bluish-green colors. Charles Darwin, as he sailed near South America on a dark night aboard the H.M.S. Beagle, encountered luminescent waves. He called it “a wonderful and most beautiful spectacle.” As far as the eye could see, he added, “the crest of every wave was bright” — so much so that the “livid flames” lit the sky.