The Mystery of the Milky Sea
What makes water glow like a galaxy?
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Imagine being as close as humanly possible to the stars — orbiting in space. You look down to Earth and what do you see? The water glows just like the galaxy around you.
This is called the Milky Sea phenomenon. It has been observed from space and Earth as early as 1846.
Sightings
In 1846, the captain of CSS Alabama, Raphael Semmes, wrote about his encounter with the Milky Sea.
“…from the deep blue water into a patch of water so light it startled me…The whole face of nature seemed changed, and with a little stretch of the imagination, the Alabama might have been conceived to be a phantom ship lighted up by the sickly and unearthly glare of a phantom sea…”
While the phenomenon is beautiful in pictures, accounts from sailors show that people who experienced it in person were mostly terrified.
An article in BBC Earth reports, “Mesmerised sailors of the 1800s had absolutely no idea what was causing the effect, but were pretty sure it was something sinister. They described it as looking like milk or clouds from horizon to horizon, plowing through molten lead or sailing on a field of snow.”
Between 1915 and 1993 the Milky Sea phenomenon was observed 235 times, mostly in the Indian Ocean near Indonesia.
Scientists explain
The Milky Sea, despite its chilling effect on sailors, did not herald sea monsters and danger.
There is one culprit behind it. But it’s multiplied by billions of trillions. A bioluminescent bacteria called Vibrio harveyi.
The glowing effect is due to “sea sparkle” (scientifically known as Noctiluca scintillans). It’s a single-celled plankton that glows when it’s disturbed. And it exists in all oceans in the world.
But while this provides clarity on the Milky Sea phenomenon it doesn’t answer all questions.
The mystery
Scientists know what organism stands behind the bioluminescent phenomenon. Or do they?
The lead researcher in this area, Steven Miller at Colorado State University, after his most extensive research of satellite images in 2005, said:
“Although such emissions cannot be fully reconciled with the known features of any light-emitting organism, these so-called “milky seas” are hypothesized to be manifestations of unusually strong bioluminescence produced by colonies of bacteria.”
But even if we knew with absolute unshakable certainty that the glowing bacteria is causing the milky seas, we don’t know much else.
What brings the bacteria to the ocean surface? Why in such large quantities?
Even if know the who we don’t know the how and why.
Meanwhile, the Milky Sea phenomenon keeps occurring at unpredictable times, locations, and sizes. Once, it was as big as the state of Connecticut.
