Wikipedia defines “an extremophile as an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth.” This means that if extremophiles were your classmates, they will totally be the cool kids in the class. Not only are extremophiles able to survive in extreme conditions; actually, many of them wouldn’t survive in supposedly “normal, moderate environments.”
What are some of these extreme conditions? Examples are highly acidic systems, highly alkaline systems, low temperatures, high temperatures, extreme UV radiation and high salinity, among others. What piques my interest as well as that of many Astrobiologists, is the fact that some of these environments that these extremophiles survive on are similar to those known to exist on other planets. This means we could have a good idea of how to prepare for some of the planets that we may someday explore, or to even decide if visiting the planet is a reasonable expedition in the first place.
Of all the extremophiles, Thermophiles are my favorite. As a matter of fact, I am planning a trip to the Yellowstone National Park because of this organism. These organisms produce some of the color at the Grand Prismatic Spring in the park! Wikipedia defines a Thermophile as “an organism that thrives at relatively high temperatures, between 41 and 122 °C (106 and 252 °F).” Many thermophiles are archaea. “Archaea” refers to microbes that have no cell nucleus, and the first observed archaea were extremophiles, living in harsh environments such as hot springs and salt lakes.