Something strange is happening to the Pacific Ocean. Near the Great Pacific Garbage Patch, the water has been reflecting more blue and green light over the past two decades.

Scientists now suspect that some of the ocean’s tiniest pollutants may be responsible.

A new study suggests that microscopic plastic particles accumulating in the water could be scattering enough sunlight to leave a detectable signature from space. If confirmed, it could give scientists a new way to track an almost invisible form of pollution.

An Ocean Sized Optical Mystery

Despite its name, the Great Pacific Garbage Patch isn’t a floating island of trash. It’s an enormous accumulation zone between Hawaii and California, where circulating ocean currents concentrate discarded fishing gear, bottles, fragments, and countless microscopic particles.

A landmark 2018 study estimated that the patch contained around 1.8 trillion pieces of plastic spread across 1.6 million square kilometers (around 1 million square miles). Microplastics accounted for approximately 94% of those pieces, although larger debris made up most of the mass.

Much of this pollution is almost impossible to see directly.