Grand Prismatic Hot Spring is the most photographed thermal feature in Yellowstone. That’s because of its crazy-bright colors and enormous size.
It might seem photoshopped, but there’s very real science beneath its vibrant colors.The pool is a piercing blue surrounded by rings of color ranging from red to green. The otherworldly effect is caused by varieties of pigmented bacteria and microbes that thrive in the warm, mineral abundant waters surrounding the hot spring. Changing along with the seasons the colors fade and grow more deep depending on what type of bacteria is thriving in the weather at the time. The center of the pool, where the water boils up from underground is so hot that the water is actually sterile.
