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Appalachian professors are part of the search for early life

carmichael_t.jpgBOONE—Professors at Appalachian State University are part of the search for signs of life across the galaxy.

Dr. Richard O. Gray.jpg
Dr. Richard O. Gray from Appalachian State University will use this six-inch robotic telescope to study 31 solar-type stars that are similar to the sun. The telescope will be installed at the university’s Dark Sky Observatory in Wilkes County and controlled remotely by computer. Studying the “young solar analogs” will provide information about the conditions necessary to support life on Earth-like planets. (Photo by Jane Nicholson)

Dr. Suzanna L. Brauer.jpgDr. Suzanna L. Bräuer, an assistant professor in Appalachian State University’s Department of Biology, collects iron and manganese oxide mineral deposits in one of the caves in eastern Tennessee and southwest Virginia where she has conducted research. The minerals are created by microbes that use reduced metals as an energy source. A similar microbial process could occur or could have occurred on Mars which also contains iron oxides. (Photo submitted)

Dr. Sarah K. Carmichael_t2.jpgUnderstanding the structure of iron and manganese oxide mineral deposits created by microbes that live off reduced metals in caves may help scientists identify early life forms on Mars. Dr. Sarah K. Carmichael, an assistant professor in Appalachian State University’s Department of Geology, travels to caves in eastern Tennessee and southwest Virginia to collect samples of the mineral deposits. Iron oxide minerals are common on Mars, indicating that the planet once had abundant liquid water. Manganese oxide minerals may also be present. It’s possible the Mars Roving Laboratory “Curiosity” will find mineral deposits created by a similar microbial process. (Photo submitted)

microscopic view of cave microorganism.jpgThis extreme close-up taken with a scanning electron microscope, shows the intricate structures of one of the many cave microorganisms which deposit minerals. (Image by Appalachian student Leigh Anne Roble)

Physics and Astronomy Professor Richard O. Gray is studying youthful sun-like stars trillions of miles away to help understand conditions on earth when life first developed. Gray’s research is supported by a three-year, $230,000 grant from the National Science Foundation.

Research by Assistant Professor Suzanna L. Bräuer from the Department of Biology and Assistant Professor Sarah K. Carmichael from the Department of Geology to better understand the microbial processes that form minerals in caves in eastern Tennessee may help NASA scientists determine if similar microbial processes are occurring on Mars. Bräuer’s and Carmichael’s work is supported by N.C. Space Grant, which is funded by NASA.

Secrets of solar-type stars

Gray’s NSF award will purchase a six-inch robotic telescope and dome that will be installed at the Department of Physics and Astronomy’s Dark Sky Observatory located 20 miles from campus in Wilkes County. Having a telescope dedicated solely to his research will allow Gray to monitor 31 “young solar analogs” that have the approximate mass, temperature and power output of the sun.

“The age of these solar-type stars encompasses the time that scientists think life first formed on earth,” Gray said. “At that time, the space environment was very unfriendly. The sun probably emitted hundreds to thousands of times more ultraviolet and X-ray radiation than it presently does and there was no protective ozone layer in the atmosphere. We are interested to learn what effect that space environment had on the development of life on earth.”

Knowing those conditions can help scientists identify earth-like planets near solar-type stars where conditions are conducive to the formation of life.

Gray will collaborate with colleagues at Marshall University and the Vatican Observatory and will use the Vatican Advanced Technology Telescope on Mount Graham in Arizona for his research.

Early life on earth, in the form of microbes, probably developed underwater or in protected crevices. “It’s just amazing that it developed to begin with, and then survived, with all the challenges it had to face” Gray said. “If we understand how life arose on earth, then we can judge the likelihood of life arising on planets orbiting other stars.”

Secrets of the red planet

A better understanding of microbial processes that occur on earth may help scientist better understand similar processes on Mars.

Bräuer and Carmichael are studying the biomineralization process that occurs in caves when microbes utilize reduced metals, such as iron, as a source of energy, much like plants harvest light energy via photosynthesis.

“These are minerals that do not have organic carbon as part of their makeup and the microbes are not using traditional pathways to obtain food. They are using metals instead of carbon as an energy source,” Carmichael said. The iron and manganese oxide mineral deposits the professors collect from caves in eastern Tennessee and southwest Virginia are a result of this unusual process.

Iron oxide minerals are common on Mars, indicating that the planet once had abundant liquid water.  Manganese oxide minerals may also be present. If so, they will likely be found by the Mars Roving Laboratory “Curiosity,” launched from Cape Canaveral on Nov. 26 and anticipated to arrive on Mars on Aug. 5, 2012.

Brauer’s and Carmichael’s research of the microorganisms present in different cave environments in east Tennessee and the biominerals they produce may help scientists determine if the iron oxides and manganese oxides found on the Mars are the result of microbial or other processes.

“Most astrobiologists agree that if life exists on Mars, it will likely be found in the subsurface, and it is probably microbial,” Carmichael wrote in the N.C. Space Grant application. “If manganese rich rock with reasonably similar structures to what we see on earth is found on Mars, it probably was formed by some kind of microorganism.”

“We are looking at the range of manganese oxide structures that can be formed from different organisms under different conditions in different environments and we use that information to hypothesize based on mineral structures from Mars whether it was likely to have formed through a biotic or abiotic process,” Bräuer said.

As part of this study, Carmichael is also comparing the mineral structures found in caves with the structures found in manganese oxide ore deposits in the southern Appalachians.  Mars is thought to have hydrothermal fluids circulating in the subsurface, and hydrothermal ore deposits on earth will provide another useful analogue for determining if a mineral’s structure is biological or abiotic.

Bräuer is also studying methane production in acidic peat bogs and peat forming wetlands in the Watauga County area. “There is methane on Mars and we are interested in looking at which type of methane-producing microorganisms are present in acidic to more pH-neutral environments,” she said.

The work of both Bräuer and Carmichael will support NASA’s understanding of the diversity of microorganisms that can produce methane and oxidize manganese as well as the manganese oxide mineral structures produced by microorganisms which might exist in different environments on Mars.