Scientists have compiled a 400-year database of Milky seas sightings — including sailor accounts, Marine Observer Journal entries, and satellite imagery — published in Earth and Space Science.
Key Highlights
- Milky seas are vast glowing stretches of ocean, sometimes up to 100,000 km² — about the size of Iceland — and can glow continuously for weeks or even months, visible even from space.
- They’ve been reported by sailors for centuries, with the glow described as similar to glow-in-the-dark stars, casting a steady green-white light.
- The likely culprit is Vibrio harveyi, a bioluminescent bacteria, but the mechanism behind the massive, coordinated glow across such large areas remains a mystery.
- Most sightings occur in remote Indian Ocean waters, especially the Arabian Sea and Southeast Asia, which is part of why they’ve been so elusive to study.
- These events may be linked to larger climate patterns like the Indian Ocean Dipole and El Niño Southern Oscillation, opening up questions about how climate variability could influence oceanic bioluminescence.
(Source: Colorado State University)
