Life from the Center of the Earth - The Shadow World of Our Hidden
Jules Verne's classic science-fiction tale, A Journey to the Center of the Earth, where the zealous Professor Von
Hardwigg finds a riddle in Icelandic parchment that leads to worlds miles beneath our planet's surface, is fast becoming science fact. Leading scientists are searching deep within the
planet to find new life forms in a shadow world of a hidden --and to find clues to what possible life might exist on others within and beyond our Solar System.
We might not have to send manned or unmanned missions to Saturn's Titan, where pools of liquid hydrocarbons might contain non-carbon-based life, or to its moon Enceladus, which has geysers of water ice and water vapor shooting through its mantle, according to Ariznoa State astrobiologist Paul Davies, author of The Goldilocks Enigma. Davies believes that "weird life" may exist right now, on Earth, in what he calls a "shadow " a microbial world that makes up 99 percent of the planet's organic mass.
The problem is, we just haven't figured out how to detect it.
Michael Meyer, lead scientist for NASA's program, agrees: "Our
capabilities of looking in the microbial world are still pretty crude.
We have marvelously sensitive techniques for finding what we've found
before."
We don't know the "rules" of organic chemistry, says
John Baross, a University of Washington biologist and the lead author
of the National Research Council report The Limits of Organic Life on Planetary Systems.
A decade ago 180 miles off the North Pacific coast, John Baross and a team of scientists and engineers are on a voyage of discovery on the Atlantis, a floating marine biological lab. They're were using what was then the world's most sophisticated submarine technology. The team was going to places where nobody has gone before.
Their mission was to discover the secret of the creation of life.
"It was," Baross said, "the same kind of fascination and sense of
discovery and exploration that I would have if I got to go to Mars."
Their
destination is the Juan de Fuca ridge 2½ kilometers down in the North
Pacific, 180 miles off the coast of Seattle. Many of them have been to
the ridge before, but this trip's different because they are hoping to
complete the final chapter in an amazing story that began over 30 years
ago. For centuries our vision of the ocean floor has been of a hostile
world of crushing pressure, extreme cold and constant darkness. It's a
world revealed only by the lights of a submarine. no-one imagined that
it could generate and support a . It was believed that with no
sunlight there would be no life.
The organic material that
supports any kind of animal-life in the deep sea comes from surface
photosynthesis, and the deeper you go, the less flux of that material
you get from the surface to the bottom and so you don't expect to see a
lot of organisms.
But this vision of the dead sea floor did not last. In the 1950s
naval surveys began to reveal evidence of huge volcanic ridges on the
ocean floor. Geologists believed there might also be underwater hot
springs releasing heat from the Earth's crust, but no-one had ever seen
them. Then in the early 70s a young geologist, Jack Corliss Central
European University, Budapest decided to go and look for them.
In August 1977 Corliss and 10 other geologists set sail on an historic voyage to the Galápagos Ridge in the East Pacific.
Corliss and his team discovered hot springs and they had also found
life: a glimmering oasis of deep sea creatures - crabs, snails and
colonies of strange tube-like animals bunched together like flowers.
Many of these life forms had never been seen by humans before.
What
they discovered Baross reported was one of the most important science
discoveries of past 25 years. "They saw all these bizarre animals,"
Baross said, "and they thought were entering into a primordial
ecosystem that had remained unchanged for perhaps tens of millions of
years, that we had entered into this lost world" of exotic creatures
living a mile and a half below the surface in one of the most hostile
places on Earth. The geologists had never seen anything like it.
The
Corliss team had entered a world without sunlight - a world of absolute
dark and all the known ecological systems on the Earth derive their
energy from the sun. This was the first total ecological system that
had ever been found that got its energy somewhere else. How did these
tube worms and weird creatures live, with no light, no photosynthesis?
When the biologists dissected the tube worms they found a remarkable
source of food: tiny, single celled bacteria. These bacteria are
chemo-synthetic. Unlike plants which look to the sun for their energy,
the microbes look to the center of the Earth. They feed on chemicals
like caustic acid and carbon dioxide that come up through the hot
springs from deep inside the bowels of the Earth. They in turn become
the basic nutrients for the tube worms and other animals higher up the
food chain.
Baross says that "I just don't think it could have
been predicted based on what we knew and it's still a big surprise
today to think that animals have co-evolved with micro-organisms of
that kind of abundance and that kind of density is still pretty
awesome."
In 1979 a new set of hot springs full of life were
discovered along the volcanic ridges where the Earth's tectonic plates
meet north of Mexico, but they revealed something even more dramatic:
huge volcanic chimneys of scalding water seeped with dissolved minerals
and silica was rising 150-feet up from the Earth's crust spewing out
clouds of black chemical-ridden smoke at unbelievably high
temperatures. On the outside these black smokers were a mere 2 degrees
Centigrade, almost freezing, but
towards the middle of the hottest chimneys it was a
raging 350 degrees. Thirty of these individual hydrothermal vents
generate the amount of energy of the largest nuclear power reactors. It
was an atmosphere like that on the early Earth that created the
building blocks for the origin of life some four billion years ago.
Fast forward to this past March at In mid-March, at a workshop funded by NSF, Baross joined more than 100 scientists gathered in Washington, D.C., to discuss the subsurface . The workshop brought together researchers from fields as varied as geology, chemical oceanography, biological oceanography, microbiology and physics.
Five years ago Cornell University theorist Thomas Gold, led discussions about how Earth could be harboring a of deep microbial life that extends for miles. Gold argued that the total mass of this might rival or exceed that of all surface life. He suggested that microbial life might be widespread throughout the upper few miles of Earth's crust, inhabiting pores and cracks among rocks and living off Earth's inner heat and broth of chemicals. Not needing sunlight, this dark world of microbes could exist independently of Earth's surface.
Gold's theory was soon put to the test by John Baross and Marv Lilley, both of the University of Washington , and Kim Juniper, of GEOTOP at the Université du Québec at Montreal, Canada, among other researchers.
In 1993, Baross and UW colleague Jody Deming published a paper entitled "Deep-sea smokers: Windows to a subsurface ?" which advanced Gold's theory by theorizing that Earth holds not only thermophilic (heat-loving) organisms, but also "superthermophilic" microbes that live at even more extreme temperatures beneath deep-sea hydrothermal vents, thriving at temperatures up to and possibly beyond 150o Centigrade (more than 300o Fahrenheit), setting a new limit at which life can exist.
According to Baross, the subsurface may be inoculating' the surface with new seeds of life. "And perhaps,' he concludes, "if there's a beneath the surface here, there might also be one under the surfaces of other planets."
The landmark National Research Council report, Limits of Organic Life on Planetary Systems, that Baross led states that "Because we have only one example of biomolecular structures that solve problems posed by life and because the human mind finds it difficult to create ideas truly different from what it already knows, it is difficult for us to imagine how life might look in environments very different from what we find on Earth."
Our journey to the center of the Earth might give us some interesting clues.
Posted by Casey Kazan.
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Is There Life on Mars? NASA Goes Underground to Find Out
What Lies Beneath -A Mystery at the Earth's Center
Unknown Species of the Underworld Discovered
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