The Grand Prismatic Spring, USA
No, you’re not looking at the eyeball of an alien, though it seems closely related. This is a photograph of a thermal feature located in Yellowstone National Park in the USA. It’s a vivid ring of colors that measure 200 to 300 feet, or 60 to 90 meters. It’s also 121 feet, or 36 meters, deep. Even though humans can’t go near it, microscopic organisms called thermophiles can. This is where the springs get their colors. The thermophiles that love the hottest part of the spring hang out in the middle and are either colorless or yellow. Thermophiles that love cooler temperatures thrive on the outside of the spring and are brown and green, hence the reason for the ring (Yellowstone Park).