evidence suggests that life originated in extreme environments,
for example, at high temperatures. The National Science
Foundation (NSF) has initiated a program called Life in
the Extreme Environment (LExEn) that is dedicated to finding
new and exciting organisms that live in harsh environments.
The Extreme 2000 research expedition, at hydrothermal vent
sites in the Sea of Cortés, is led by marine scientists
George Luther and Craig Cary from the University of Delaware
and Anna-Louise Reysenbach from Portland State University.
Their chief objective is to make real-time chemical measurements
at the vents using microsensors developed by Dr. Luthers
group, which will guide the microbiologists and molecular
biologists in Dr. Carys and Dr. Reysenbachs
groups in finding organisms that are descendants of early
Chemical Detective Work at the Bottom
of the Sea
hydrothermal vents home to the closest relatives of the
oldest life on Earth? Using special tools housed in a wand
on the sub Alvin, researchers will be testing the
chemistry of vent water in search of microscopic organisms.
The wand houses a thermometer, an apparatus called the
Sipper to collect small water samples, and a super-sensitive
The analyzer is like a sophisticated underwater snooper.
It can be used near the vents and, from its chemical readings,
tell scientists what kind of microbes might live there.
While our food chain is based on energy from the sun, the
suns rays never reach the deep sea. There, organisms
must rely on a different energy source: the chemicals that
rocket out of the vents.
During a previous expedition, the Extreme 2000 scientific
team found that the presence of two compounds hydrogen
sulfide (H2S) and iron monosulfide (FeS) may be an
important indicator of the oldest microscopic vent life.
These compounds react to form the mineral pyrite (fools
gold) and hydrogen gas. The hydrogen provides the
energy that these microbes need to grow.
With the analyzers help, marine scientists may be
able to track down the nearest descendants of the first
life on Earth, and perhaps on other planets.
Europa, one of the moons of Jupiter, is covered in ice.
However, recent findings suggest that portions of the ice
move, which is strong evidence that liquid water lies beneath
the ice. The water may be maintained in its liquid state
by hydrothermal vents. If hydrothermal vents exist on Europa,
theres a possibility that ancient microbes could live