Above and Below
How did the universe evolve? Will the universe continue to expand? Astronomers use a year-round observatory at the South Pole to answer these questions, taking advantage of the Pole's natural features: the dark, dry, and cold environment makes for easier detection of infrared wavelengths and small particles. Infrared and submillimeter radio telescopes at the South Pole detect wavelengths obscured at most other observing sites. NSF-funded researchers use the Antarctic ice sheet to capture invisible, subatomic particles called neutrinos in order to gain insight into violent astrophysical events such as black hole collapses and supernova explosions.
Another territory ripe for exploration can be found deep below the ice. Thousands of feet under the Antarctic surface, below the Russian-run research station known as Vostok, lies Lake Vostok. The subglacial lake, roughly the size of Lake Ontario, has been isolated from Earth's ecosystem for millions of years. Cut off from the rest of the Earth, Lake Vostok may be home to ancient species of microbes that have been able to survive in this extreme environment. As part of a joint U.S., French, and Russian research project, Russian teams have drilled down into the ice covering the lake and extracted the world's longest, deepest ice core. They stopped drilling at about 395 feet above the ice-water interface to prevent possible contamination of the underlying lake by kerosene-based drilling fluid.
The upper 9,800 feet of the ice core provide a continuous paleoclimatic record of the last 400,000 years. The record shows that there have been four complete climatic cycles, including four ice age or glacial periods associated with the development of large ice sheets over the Northern Hemisphere, and four warmer interglacial periods.
In addition, NSF-funded scientists discovered that the core contains bacterial forms, showing that microbes existed under the ice and probably still thrive in the lake. How do such "extremophiles" survive? Where do they get their energy - from geothermal activity? Studying the microbes and their unique and isolated environment will tell scientists more about whether life may be able to exist in harsh conditions elsewhere in the solar system. Indeed, Lake Vostok appears to resemble conditions on Jupiter's frozen moon Europa. Scientists and engineers are now working on methods to sample the subglacial lake while preventing contamination.
Moving up in scale from microbes, biologists continue to discover important adaptations among larger extremophiles. In the late 1960s, physiologist Arthur L. DeVries discovered with the help of NSF funds that Antarctic notothenioid fish are protected from subzero temperatures by antifreeze glycoproteins in their blood. Continuing studies to unravel the workings of fish antifreeze could have profound implications in a number of areasfrom human organ transplantation to agriculture and beyond. As it happens, Arctic cod have similar glycoproteins. These proteins bind to ice crystals and keep them from growing. Yet NSF-funded studies in the 1990s revealed that the Arctic cod and Antarctic notothenioid actually belong to two different orders of fish that diverged in evolution some forty million years ago. This is a striking case of convergent evolution in polar environments: the fish took different routes toward the identical solution of how to stay alive in ice water.