Uninhabited water: Where no microbe has gone before

May 13, 2010

(PhysOrg.com) -- NASA's 'follow the water' strategy to find life on other planets might need rethinking, according to Australian National University research describing the amount of water on Earth that doesn't support life.

In an effort to find the limits of , ANU PhD student Eriita Jones and Dr Charles Lineweaver from the ANU Planetary Science Institute have mapped out the ‘uninhabited’ water on Earth.

The researchers say that life on Earth is constrained to live in a thin shell that amounts to less than 1 per cent of the volume of the planet. Yet roughly 3.5 per cent of the volume of the Earth can have liquid water in it.

“Our initial goal was to locate regions on Mars where the temperatures and pressures are suitable for life, but we soon realized that since we know a lot more about the Earth we should look here first,” Ms Jones said. “Our initial expectation was that we would find all liquid water on Earth to be inhabited. We were surprised to find that this wasn’t the case.”

The researchers compared the extent of liquid water environments on Earth with the environments inhabited by terrestrial life in order to locate ‘uninhabited’ water. Although all terrestrial life requires during some phase of its , the researchers found not just any water will do. Some water is too hot or too cold or too salty or too poor in nutrients to support life.

“We compiled global temperature and pressure limits to get a comprehensive view of the environmental limits of terrestrial life,” Ms Jones said. “We mapped out all possible environments on Earth where there is water and all the environments in which life is known to exist. We found that roughly 1 per cent of the water on Earth is ‘uninhabited’, but that 1 per cent is incredibly spread out in the crust and . This means that 88 per cent of the volume of the Earth where there is some is uninhabited.”

Dr Lineweaver said: “Even after roughly four billion years of evolution, life on Earth has not been able to figure out how to live in some water on this planet. The fundamental limits that we have identified may be more than just limits on terrestrial life - they may apply to any terrestrial-like life in the universe.”

The researchers’ paper To What Extent Does Terrestrial Life “Follow the Water”? is being published this week in the journal Astrobiology. A proceedings paper, Pressure-temperature phase diagram of the , provides more information.

Explore further: Study links swarm of quakes in Texas to natural gas drilling

More information: Both papers are available at www.mso.anu.edu.au/~charley/publications.html

Related Stories

Twinkle, twinkle, any star - Sun not so special

May 21, 2008

ANU astronomers have found there is nothing special about the Sun after conducting the most comprehensive comparison of it with other stars – adding weight to the idea that life could be common in the universe.

How water forms where Earth-like planets are born

Dec 17, 2009

(PhysOrg.com) -- In a study that helps to explain the origins of water on Earth, University of Michigan astronomers have found that water vapor can form spontaneously in habitable zones of solar systems, and that it develops ...

Rare Scottish mineral may indicate life on Mars

Dec 10, 2009

(PhysOrg.com) -- A team of NASA (National Aeronautics and Space Administration) scientists is looking for clues about life on Mars in an earthy clay mineral found only in Aberdeenshire in Scotland.

NASA images, White Sands features support a wetter Mars

Dec 07, 2006

NASA's announcement yesterday of evidence that water still flows on Mars, at least in brief spurts, demonstrates that the view of Mars as a very dry planet should be reevaluated, says Dawn Sumner, professor of geology at UC ...

Recommended for you

Study reveals 'two faces' of phytoplankton

19 minutes ago

Phytoplankton, commonly known as plant plankton that remove carbon dioxide from the atmosphere through photosynthesis, are potentially a key driver of Arctic warming under greenhouse warming, a study reveals.

Frontier science in ocean-going lab

3 hours ago

Oceanographer Dr Martina Doblin is preparing for one of the most significant explorations of her career. In early June, a mobile laboratory known as the Micro-CSI will leave from Brisbane aboard Australia's ...

Extending climate predictability beyond El Nino

6 hours ago

Tropical Pacific climate variations and their global weather impacts may be predicted much further in advance than previously thought, according to research by an international team of climate scientists ...

Ocean currents impact methane consumption

23 hours ago

Large amounts of methane - whether as free gas or as solid gas hydrates - can be found in the sea floor along the ocean shores. When the hydrates dissolve or when the gas finds pathways in the sea floor to ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

DigiMc
not rated yet May 14, 2010
If 99% of Earth's water supports life - how does that invalidate "follow the water" strategy?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.