Life at the extremes: What does life need to exist?  We all need to be able to make energy to grow and reproduce.  Humans make energy by breathing air and eating food, but this is not the case for all of life on Earth, nor would it necessarily be possible on other planets. How do organisms survive in extreme Earth environments? For example, microorganisms live where there is no oxygen or air, they also live in ice, boiling springs, salt, acidic waters, and even in rocks buried thousands of metres below the Earth’s surface. Understanding the diversity and limits of life on Earth helps us to define our search for signs of life on other planets including possible chemical and geological signatures.

University of Manchester, School of Earth & Environmental Sciences, Geomicrobiology