Did you ever think life was possible deep under the ice in Antarctica or in volcanic vent in the ocean?
Some microorganisms can survive in very harsh circumstances that would kill other living creatures.
Scientists call them extremophiles, which means "lovers of extremes".
We can find them in unexpected places like hot springs, soil, rocks, ice and even deep in the ocean.
Studying and understanding extreme forms of life on Earth will help us in our search for life on planets with harsh environments.
Although the list of extremophiles keeps getting longer as new ones are discovered, we will describe some of the most interesting:
Thermophiles - hot lovers
Psychophiles - cold lovers
Barophiles- pressure lovers
Halophiles - salt lovers
Radioresistant - radiation fighters
Thermophiles and hyperthermophiles are microorganisms that live in very hot water.
They normally reside in hot springs
or hydrothermal vents
on the ocean floor,
where temperature can vary between 50C/122F and 110C/230 F.
discovered in acidic hot springs is a very interesting microorganism that is both a
thermophile and an acidophile (an organism that thrives in an acidic environment).
Psychophiles are the opposite of thermophiles. They love very cold places and can thrive in temperatures
below the freezing point of water. They reside in cold soils, ocean water, permafrost
and even polar ice.
In order to survive at such low temperatures, they have developed special proteins that act like antifreeze
and lower the freezing point of water.
Salty environments will kill many microorganisms because the salt outside the cell will cause the water inside the cell
to exit leaving cells dried out and incapable of carrying out normal functions.
Halophiles are able to maintain the proper water balance in their cells because of special proteins.
They can be found anywhere there is salt. They live in cold, hot, wet, dry, alkaline and neutral environments.
High pressure environments, such as those found at the bottom of the ocean, can kill many organisms. Not so with barophiles,
which have developed mechanisms to thrive in these settings. In fact, some types of barophiles, known as
obligatory barophiles, are so highly specialized that they cannot survive outside of these environments.
Radioresistant organisms can survive at very high level of radiation.
They have excellent restoring systems that help them quickly repair damage caused by high energy radiation like
solar UV radiation
The existence of such ability opens the possibility for the migration of life from one planet to another.