SEARCHING FOR ORIGINS OF EXTRATERRESTRIAL LIFE
We have become aware of increasingly more common reports of unusual aerial sightings in various parts of North America, both rural and urban. The more credible of these reports again raise the question about extraterrestrial life and in what form it might present. One logical approach in the search for origins of life (as we define it) on earth as well as extraterrestrial life is to seek tangible biochemical evidence.
That is precisely the aim of the NASA Astrobiology research program. Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe: extraterrestrial life and life on Earth. It uses physics, chemistry, astronomy, biology, molecular biology, ecology, planetary science, geography, and geology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth. The origin and early evolution of life is an inseparable part of the discipline of astrobiology. This interdisciplinary field encompasses research on the origin and evolution of planetary systems, origins of organic compounds in space, rock-water-carbon interactions, abiogenesis on Earth, planetary habitability, research on biosignatures for life detection, and studies on the potential for life to adapt to challenges on Earth and in outer space.
Ultraviolet (UV) radiation is more intense in space and may have been greater on earth’s surface early in its existence than it is now. Presuming that life in its infant cellular state would require protection from UV radiation, NASA is searching for protective mechanisms that would allow life to arise and thrive in such a hostile environment. One such mechanism is the development of biofilm, a community of microorganisms which secrete a slimy extracellular matrix. There are many biofilms present in nature, including dental plaque. Biofilms are complex functional biological systems which likely block the harmful effects of UV radiation.
An excellent site to study biofilms is in Yellowstone national park, loaded with large animals, which contains a very large geologically active caldera of a supervolcano. There are over 1200 active geysers, about a third of which are active in an average year. On the edges of the superheated, nearly 200 degree F pools, are found a variety of extremophile organisms, similar to bacteria, which form biofilm.
An extremophile is microorganism that lives in conditions of extreme temperature, acidity, alkalinity, or chemical concentration. As a stream leaves a pool, it forms a gradient of heated water and different extremophiles take up residence at different temperatures. The NASA Astrobiology research program directed by Dr. Nancy Hinman studies the geological and biochemical properties of the microoganisms living on the edges of the pools and streams.
Her team monitors growth and loss of photochemically-active components such as hydrogen peroxide and collects thermophilic biofilms to address questions about the reactions that took place on planetary surfaces. The group is particularly interested in processes that lead to preservation of microfossils and biosignatures on Earth that can be extrapolated to processes that may occur on Mars.
My son and I joined Dr. Hinman and team along with 2 nationally-selected Eagle Scouts from the National Eagle Scout Association (NESA) World Explorer Program which I direct. We sampled biofilms in areas of Yellowstone not accessible to the public, very colorful and spectacular. It was a beautiful and intriguing experience and the data captured provided interesting results being analyzed for publication. However, visitors to the park can certainly view similar sites from the safety of the walkways. Just don’t get too close to the pools, they have treacherously thin edges and you may end up in the soup……literally!