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?