When you first think about it, there’s nothing really impressive about bacteria. I mean, most of them can’t even be seen without a microscope, they cause diseases and infections; overall pretty boring things, right?

You might change your mind after hearing about “extremophiles,” though. Extremophiles are a classification of bacteria that live in extreme environments, or places that are completely uninhabitable for human life. In fact, before the discovery of extremophiles, these environments were deemed unfit to support any life at all. Never underestimate anything, even if its microscopic!

The cool thing about extremophiles is how many different kinds there are! Like thermophiles (live in extreme heat) and psychrophiles (live in extreme cold), some prefer places where the temperature pushes our planet’s boundaries. Thermophiles can be found living in or around places like hot springs, where water temperatures sit around 140 degrees Fahrenheit (60 degrees celsius). On the other side of the spectrum, if you want to find a few psychrophiles, I’d recommend looking in glaciers or far beneath the ocean’s surface. And don’t forget a coat!

The fun doesn’t just end with temperatures! There are other kinds of crazy bacteria, such as halophiles (live in extremely salty conditions), barophiles (live under immense pressure), and osmophiles (live in conditions with high sugar concentrations). Some extremophiles even fall under multiple of these categories, and they’re known as polyextremophiles. An example of this kind of organism is called a Tardigrade, or water bear. And believe it or not, the Tardigrades have been deemed the most resilient organism living on planet Earth! They can be found anywhere and reported from the top of the Himalaya mountains to the deep sea. All while being so tiny; truly a remarkable creature!

Now, though the probability of running into most extremophiles is pretty small, it's interesting to think that organisms like this exist on our planet! And actually, they may not be just on Earth for much longer! Scientists have sent some of these bacteria to the planet Mars to see how they endure the conditions elsewhere, and others have already hypothesized that extremophiles are already living on various planets and moons in our solar system. Extremophiles have given us a new definition of what conditions lifeforms can endure; certainly a feat worth noting!