NASA Earth Observatory
This striking green-blue image isn't a lost work of Van Gogh - it's a giant, growing bloom of microscopic plants and animals in the Baltic Sea, which NASA photographed from space on August 11.
But don't let its beauty fool you.
NASA suggests the bloom might contain cyanobacteria. The marine bacteria are big oxygen producers but can threaten wildlife if they grow out of control. Some species can also be toxic and threaten the food supply. What's more, cruise ships full of summer tourists might be inadvertently feeding the blooms.
Keep scrolling to see some incredible views of the bloom, including ships cutting through the biological "carpet" that's coating a popular vacation spot.