Some of the people doing polar research these days have their feet on the frozen ground but their eyes on the skies. Conditions of deep cold significantly reduce the chance of biological contamination, making polar ice an excellent place to gather meteorites. Polar environments have also proven to be good places to develop technologies that may one day be used to explore Mars.
The more we observe of worlds like Mars and Jupiter's moon Europa, the more we find similarities--analogs--to environments at Earth's poles; conversely, exploring polar environments may help us explore those other worlds more effectively. This offers opportunities for aspiring scientists whose sights are set on the ends of Earth--and beyond.
Photo: The CMaRS for Antarctic field use.
Left to Right: David Dickensheets, Montana State University, Roger Worland, British Antarctic Survey, David Wynn-Williams, British Antarctic Survey, Chelle Crowder, Montanta State University (Chelle is the graduate student who built the instrument shown in the foreground).
Solar System Samples
The dream of many a planetary scientist is a sample-return mission, bringing back a piece of another world, comet, or asteroid for study, as the Apollo missions did for the moon. But one expedition supplies hundreds of samples each year at a fraction of the cost of a human or robotic space mission. Since 1978, the Antarctic Search for Meteorites ( ANSMET) has sent between four and 12 people at a time to spend austral summers (5 to 7 weeks, generally between mid-November and January) searching glaciers and ice fields for meteorite impacts.
For the past decade, Ralph Harvey has served as ANSMET's principal investigator and leader of its expedition team. "The southern polar region represents a unique platform for observation," he says. "One of the great values of the Antarctic is its areas unspoiled by humans or other biological organisms." This makes the ice fields of the Antarctic ideal for preserving meteorites free from contamination.
"Even the Arctic is extremely different--teeming with life compared to Antarctica. A huge component of arctic research is biology--not the geographically isolated communities of life found in Antarctica, but a whole ecology, including human cultures."
During the 2001-2002 season, the expedition focused on the western end of the Darwin Mountains, in an area named Meteorite Hills following the discovery of numerous meteorites there in 1978. During the season, expedition members live in tents on the ice fields where they search, and they get around on foot or snowmobile, taking full advantage of 24 daily hours of sunlight to peer across blue ice (a "meteorite stranding surface") in search of meteorite specimens.
Searches are systematic: The position of each discovered meteorite is logged, and the meteorite itself is examined, given a numerical designation, removed, and placed in a sterile Teflon bag. The still-frozen specimens are transferred to the Johnson Space Center in Houston, where they are further examined and described in clean-room conditions. Samples are then sent to the Smithsonian Institution in Washington, D.C., where other experts examine them, and they are finally made available to the international research community for study. Over the years, the thousands of samples gathered by ANSMET have greatly increased our knowledge of planetary science.
By now ANSMET's connection to Mars research is well known. It gathered the specimen (EETA79001) that provided conclusive evidence of Mars origin. It has collected five of the 18 specimens identified as coming from Mars, including the specimen ALH84001, collected in 1984 and made famous in 1996 when NASA investigators suggested that secondary materials in the cracks of the meteorite might have been created through processes involving life--although most planetary scientists now think otherwise.
Searching for Life in Antarctica's Dry Valleys
While ANSMET spends time searching mountain ice, other scientists are examining Antarctica's Dry Valleys--among the coldest, driest places in the world--for signs of life. Twenty years ago small isolated colonies of bacteria, algae, and fungi were discovered living there. More recently, scientists from Canada and New Zealand found colonies of bacteria and fungi hidden away in paleosols--ancient soils created by the advance and retreat of glaciers--in conditions that are similar to Mars's past and present.
The search for tiny, microscopic forms of life, including fossilized microbes, requires specialized instruments and cooperation between field researchers and instrument builders. David Wynn-Williams, a microbiologist for the British Antarctic Survey, studies the cyanobacteria that inhabit porous sandstone rocks in the Dry Valleys. Wynn-Williams will soon use a mini Raman spectrometer--called a CMaRS--that he can carry into the field in his backpack to detect the fossilized pigments of ancient cyanobacteria. He is developing a catalog of the biomolecules found in fossilized and living samples that may one day be used in a Mars mission to identify living organisms or their fossilized remains. A Raman spectrometer has been proposed for the Mars Express Lander mission in 2005.
Chris Schoen of TRI Inc. and David Dickensheets of Montana State University, Bozeman, collaborated in the design of the CMaRS, adapting a design originally intended for petroleum industry field work. "A lot of instruments used in scientific investigations are developed as prototypes put together in academic or scientific laboratories," says Dickensheets, whose work on CMaRS is funded by the NASA Astrobiology Institute. His work on the design of miniature optical elements, "small lightweight instruments to be used for remote microscopy inside human beings," became the basis for the microscope attachment that makes CMaRS useful in the field.
Dickensheets came late to the design of instruments for scientific exploration. After getting his bachelor's and master's degrees, he went to work for Hewlett Packard where he worked on biomedical instruments. He became interested in designing instruments for field work when he returned for his Ph.D. at Stanford. "I don't consider myself a polar researcher or a space researcher, but rather an instrument maker," he says. Nonetheless, he is looking forward to his first trip to the Antarctic next year. "I learned from HP to meet with customers first-hand. Seeing it for yourself is an important part of the feedback."
Europa--Life on Ice
Polar research may help us search for life even beyond Mars. Astrobiologists agree that organic life may exist in environments where there are organic chemicals, energy sources, and water. According to planetary geologist Ronald Greeley, "Jupiter's moon Europa, along with Mars and Saturn's moon Titan, tops the list of likely candidates for life." Greeley, chair of the NASA Astrobiology Institute's Europa Focus Group, sees promise in using the discoveries of polar research to understand the chemistry, physics, and biology that may exist on Europa.
Slightly smaller than Earth's moon, Europa contains perhaps three times the volume of water of Earth's oceans. Its surface is frozen ice cracked by the massive tidal forces of Jupiter and nearby satellites. These forces also serve as Europa's energy source, heating its iron-nickel core and creating undersea hydrothermal vents that may circulate heat and minerals. These may also host life forms like those inhabiting hydrothermal vents on Earth.
Life beneath Europa's thick ice surface will be difficult to detect, but polar research suggests that other opportunities to find life may exist. Greeley says, "In the Antarctic, microcracks in the ice often serve as reservoirs for liquid water and cold-tolerant microorganisms to grow and flourish. Similar microcracks within Europa's ice, especially if nourished by brine upwelling from the liquid seas below, may also hold living organisms."
* ANSMET information. Includes maps, journal entries, contact information, and an explanation of the science behind the search for meteorites.
* ANSMET's home page at Case Western Reserve University, Ralph Harvey's home base.
* Home page of the NASA Astrobiology Institute, which includes information on Wynn-Williams's work, the Europa Focus Group, and more.
* Montana State University's Electrical and Computer Engineering Department home page, David Dickensheets's home base.
* Home page of Astrobiology at Arizona State University, Ronald Greeley's home base. Has more information on astrobiology.
* Apply for a NSF research grant to work in Antarctica.
* Teachers Experiencing the Antarctic and Arctic. A site for teachers interested in joining research expeditions at the poles.
According to Harvey, ANSMET seeks volunteers each year for its expeditions. "We've had a hundred different people in 25 years." Harvey is especially interested in involving students or scientists already researching antarctic meteorites. "This is a program that can benefit the researchers themselves, to understand how samples are gathered."
But for would-be professional meteorite hunters, Harvey is less sanguine. "People often train themselves to be clones of their advisor or another scientist. A better tactic is to find a new niche rather than duplicating what's being done. See what isn't being done--that's often where the fruitful paths lie. The world needs only so many meteorite hunters."
"There's a lot of room for growth in the polar sciences--we're still in the exploration and description phase there as far as the science goes. But it's a higher-stakes game than laboratory research. Supporting any kind of research there is expensive. It's guaranteed to be an area where ideas exceed money. On the other hand, there are lots of things to do if you can get there."
Harvey advises students interested in polar or planetary science to "have a specific idea of what you want to accomplish and then seek out an advisor who can guide you in ways known to work. Your relationship with your advisor is one of the most important of your life. Get involved in an existing program and then find your niche. It's a hard thing to do, but put effort into your research design from the very beginning, even as you are learning."
According to Dickensheets, instrument design requires a broad area of expertise. "Physics, computer savvy, real-time computer design, mechanical design, not to mention the ability to understand from your customers what their needs are." Instrument design and construction is often a team effort, and Dickensheets's students, both graduate and undergraduate, have participated in instrument design and construction. He encourages would-be instrument makers to look into university-level science and engineering departments and look for instrument-development projects to get involved in.
Dickensheets has found his experience with commercial instruments to be beneficial, and like most academics in engineering today, trains his students to be practical problem-solvers. "There's a lot of overlap on instruments in the medical and telecommunications sectors. If they don't find work at the Jet Propulsion Laboratory, they can make a good living in private industry."
Greeley, for his part, looks for students and researchers who are "bright, enthusiastic, and reliable." His advice? "Get a bachelor's degree in a basic scientific field--physics, biology, chemistry, astronomy--the basic field doesn't matter for planetary science. Then shop for graduate schools. Go where the action is, and visit and talk with the faculty to make sure you have the right fit."