Living Thermometer

Thermophiles, microorganisms adapted to heat, live in geysers and runoff channels where different kinds occupy different temperature zones, creating a “living thermometer” in and around Whirligig Geyser. In Whirligig’s iron-rich runoff channel, where temperatures of 122 - 140° F (50 - 60° C) are hot enough to burn people, thermophiles use iron for energy and become coated with rust; these chemical-users are called chemotrophs. In the green channel, thermophilic algae including Cyanidium photosynthesize using sunlight for energy; these phototrophs live where temperatures range from 100 - 133° F (38 - 56° C). In Norris Geyser Basin, which is highly acidic, thermophiles thrive on heat and acid, and although they are too small to see without a microscope, their vast communities are clearly visible. The number living beneath a ten-inch square may exceed the number of people on Earth. Scientists study these thermophiles to understand how life has adapted to iron-rich, acidic conditions, and they use the mineral deposits that record this extreme habitat to help search for similar deposits and possible life on Mars.

Wyoming · United States