Jun 29, 2008

Life on the Edge Update

June 29, 2008: On May 26 th astronomer Tony Phillips and his team of Siberian Huskies successfully mushed to the top of California's White Mountains to retrieve yeast and other microorganisms left there earlier this year as part of the Life on the Edge education initiative. The yeast packets are now on their way to the Marshall Space Flight Center in Huntsville, Alabama, for testing and distribution to classrooms around the world.

Life on the Edge is a program that aims to teach grade school students about one of the newest, exciting disciplines in modern science -- astrobiology and the study of life in extreme environments.

See Mercury at Sunset (lote3 #1)
Tony Phillips and his team of six sled dogs approach the snow line near 12,000 ft on a blustery spring day in the White Mountains. Photo Credit: Paul King, BBC Science Mysteries

During the past 20 years, scientists have come to realize that life can exist in remarkable places such as scalding hot geothermal vents, Antarctic ice, and even inside a nuclear reactor! The discovery of "extremophiles," or microbes that thrive in extreme environments, here on Earth has convinced many scientists that simple forms of life might one day be found on other planets in our Solar System that were previously thought to be too hostile for life as we know it.

Many of these exciting developments in astrobiology are relatively unknown in public schools. Life on the Edge is intended to remedy that. The basic idea of the program is to expose a variety of interesting, but benign microbes to real-life harsh environments on Earth, to retrieve the microbes after a suitable period of exposure, and finally to distribute them to grade school classrooms. Students can then perform original experiments on their microorganisms to evaluate how well they survived their "ordeal" and to explore which environmental factors were most important to the health (or demise) of the samples.

"We want the students to be exposed to NASA research, and to think about issues related to life in extreme environments that might not otherwise come to light. One example might be the role of water in supporting life. Liquid water is very important to life forms on Earth, but it isn't equally abundant on every other planet in the solar system - if it's even there at all."Microbes can remain viable in the absence of water (the Surveyor 3  microbes on the Moon are a good example) but do they mate, divide, and metabolize? Are they really and truly engaged in the business of "life?" What kinds of other environments can they survive?

See Mercury at Sunset (lote3 #2)
3rd grade students in Bishop California demonstrate a Life on the Edge classroom protocol called Planets in a Bottle

"These are the kinds of questions we want kids to think about and work through in their own minds," Phillips noted. "And simple dried yeast is an excellent and very safe organism for these kids to work with and explore."

The program began In January 1999 when 50 pounds of yeast were delivered to a summit in California's White Mountains. Conditions there present severe challenges for most forms of life, so it is a good place to test the response of microbes to extreme environments.

"Life on the Edge is just getting started. This year we field-tested some of our ideas in the White Mountains. We had to answer questions like 'Does the yeast canister really establish thermal contact between the microbes and the ambient environment?' And 'Can we design a vessel that exposed the microbes to a fuller range of environmental factors [like wind, humidity, and competition with local life forms] without the yeast blowing away?'

"Our preliminary feedback from students has been exceptional, and I expect we'll continue to work in the Whites for years to come," he continued, "but we'd also like to expand Life on the Edge to include other places like the Alaskan tundra, Mono Lake, and even the South Pole.

See Mercury at Sunset (lote3 #3)
A BBC cameraman takes a breather at Barcroft Station (12,500 ft) in the White Mountains. Breathing pure oxygen can briefly ameliorate the symptoms of altitude sickness, which include headaches, disorientation, and nausea. Photo Credit: Paul King, BBC Science Mysteries.

When the yeast packets were conveyed to the White Mountains in early 2008, it was bitterly cold and the snow line was near 9000 ft elevation. When Phillips and his team returned in late May, a warm La Nina-driven spring had raised the snow line all the way up to 12,000 ft.

"Spring sledding can be really challenging," said Tony Phillips. "For one thing, it's warm. Up in the Whites that means the thermometer's hovering around freezing and it's only snowing a little bit. Huskies love to pull when the temperature is about 30 degrees below zero, so a 2000 or 3000 ft ascent in freezing (32o F) weather was hot work for them."

"The only time they pulled with their usual energy was when they smelled a marmot. Yellow-bellied marmots are small (15 - 24 inches long) furry mammals that live in the mountains all over Central California. They usually hibernate from early fall until March, then they disappear again in June to sleep away the hottest summer months. Of course, there are no marmots at the 14,000 ft summit, but we saw dozens at lower elevations. To be absolutely truthful, I should say that the dogs saw them. I only knew when we passed one because the dogs would suddenly veer off the trail and send the sled catapulting over the big rocks that were beginning to emerge from the melting snow. On one occasion they left me behind, flat on my back. The only reason I caught the team was that they had cornered a marmot under a rock and were fighting over who got to go in after it. They never caught a single marmot but they nearly killed me.

"Honestly, the best part of Life on the Edge is that it's so much fun," concluded Phillips.