English: The north and western coast of Mexico’s Yucatan Peninsula wore a bright halo of blues, greens, and tan in late October 2021. The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of the colorful scene on October 31. The coast-hugging swirls most likely come from sediment floating in the waters and carried by the currents of the Bay of Campeche. Sediment scatters light and this reflectivity gives water characteristic color when viewed from space. When floating near the surface, sediment appears muddy-tan but as sediment sinks and disperses the color changes to shades of green and blue. The sediment most likely comes from two sources: run-off from the land (via rivers or direct runoff) and churned up from the sea floor by tide and currents. Some of the color may also come from phytoplankton—microscopic plant-like organisms—that sometimes float on the surface in blooms large enough to be seen from space.