E X P L O R I N G A S T R O B I O L O G Y: Where is life found on Earth? Life Finds A Way Atacama Desert, Chile Image: CalTech Knowing where life is found on Earth helps us look for extraterrestrial life. Amazingly, as long as some basic requirements for survival are met, life finds a way to thrive almost everywhere on Earth! E X P L O R I N G A S T R O B I O L O G Y: Where is life found on Earth? Basic Requirements Of Life Image: NASA/ ESA An ongoing source of energy is required to sustain life. This energy can come from sunlight, other organisms, carbohydrates and lipids, chemicals from undersea vents, methane, and a host of other sources. E X P L O R I N G A S T R O B I O L O G Y: Where is life found on Earth? Basic Requirements Of Life Image: NASA/ JPL Life as we know it also requires liquid water, and a specific range of temperatures. Above 266°F (130°C), organic molecules fall apart. Some large animals can tolerate low temperatures, but most bacteria and microbes can’t function below -4°F (-20°C). E X P L O R I N G A S T R O B I O L O G Y: Where is life found on Earth? Living On The Edge Hydrothermal Vent In the Atlantic Ocean Acidic, toxic water- Rio Tinto, Spain Extremely salty water , San Francisco Bay Antarctic ice Hot spring, Yellowstone National Park There are places on Earth that seem too hostile for survival—but tough organisms called “extremophiles” find a way to occupy even these unlikely locations. E X P L O R I N G A S T R O B I O L O G Y: Where is life found on Earth? Survival Specialists Methane-eating ice worm from Atlantic seafloor Image: Penn State University/ NOAA Cold-loving microbes adapted to living in polar sea ice Image: Christian Knoblauch Most extremophiles are microbes, though some are larger—like methane-eating ice worms! Their biochemistry, metabolism, and physiology are different from those of most species, having evolved to thrive in extreme environments. E X P L O R I N G A S T R O B I O L O G Y: Where is life found on Earth? More Extremophiles Bacteria under the surfaces of rocks in the bone-dry Atacama desert Microbes living in pockets of water under Antarctic ice Image: NOAA Image: Carnegie Mellon University Robotics Institute Bacteria living in droplets of water in clouds Extremophiles can survive in extreme heat and cold, high radiation, very dry areas, droplets of water in clouds, and even in the depths of caves— where they live in and eat solid rock! Life keeps surprising us with its ability to adapt to challenging circumstances here on Earth. Who knows where it might exist elsewhere?