Microbial
life from the depths of Ballston Lake may shed some light on the kinds of
life forms that NASA scientists should look for on Mars and elsewhere.
Paul Gremillion, assistant professor of civil
engineering, traveled to Kennedy Space Center in Florida recently to speak
to scientists on “Understanding Biological Artifacts of Extreme
Environments.”
He related the highly unusual water chemistry and
microbial ecology of Ballston Lake with some of the ongoing work at NASA,
including the search for evidence of microbial activity on Mars and
exploration of the perennially ice-covered oceans of Europa, a moon of
Jupiter.
He presented this talk to a group of scientists and
engineers working in ecological programs at the Merritt Island space
facility and on the Mars and lunar colonization program.
Gremillion, who specializes in chemical systems found in
lakes, was invited by a former colleague who directs life sciences support
for shuttle missions.
NASA recently lost a Mars probe – the Climate Orbiter
— that was to aid in the investigation of life on Mars. Its sister ship
– the Polar Lander – is to land on Dec. 3. Scientists are designing a
probe to penetrate the ice and sample the water on Europa, Gremillion
said. The next mission to Europa is planned for launch in November 2003.
“I wanted to tie in the unusual environment of
Ballston Lake with some of the things that they study,” Gremillion
said. “Nobody there studies lakes, but they do a lot of biological
and ecological work on odd systems, like looking for evidence of what
microbial evidence on Mars might look like. If life exists or existed, it
stands to reason that it may be astonishingly different than on
Earth.”
For example, scientists might expect microbial life on
Mars to be photosynthetic but not use oxygen, much like some of the
microbes Gremillion, his students and colleagues have found in Ballston
Lake.
NASA scientists are investigating microbes found in
extreme environments on earth, like those found near hydrothermal vents on
the ocean floor, Gremillion said. “These life forms are not the
typical base of the food chain, the chlorophyll-bearing algae,” he
said.
On the surface, Ballston Lake is like any other. But the
south end is deep and narrow; there is not adequate wave action to
circulate the water column, as happens in most lakes. About 18 meters
down, you'll find the chemocline – a chemical stratification of
oxygen-depleted water that has high levels of iron and low levels of
sulfate. In other words, the environment at and below the chemocline is
extreme, Gremillion said. Yet, there are life forms – microscopic
bacteria — that thrive there.
Gremillion is one of a number of faculty and students
doing research under the Ballston Lake Initiative, a multidisciplinary
research project examining the natural processes and effects of human
impact on the lake. Project director in John Garver, director of
environmental studies.