Mar 12, 2008

Sled Dogs Carry Astrobiology to Dizzying Heights

Mar. 12, 2008: Last month a 50 lb canister of yeast and other microbes arrived at a 13,000 ft summit in California's White Mountains. It was the first step in a new educational program called "Life on the Edge," which aims to expose grade school students to some of the basic principles of astrobiology and to explore the possibilities for life elsewhere in the Solar System.

Spotless Sun (lote2, #1)
Tovic (left) and Ruby (right) enjoy frigid conditions in the White Mountains on a run in early February. These two Huskies are members of an eight dog team that has traveled into the White Mountains several times this year to convey and monitor "Life on the Edge" microbe vessels. The sled, pictured in the background, is pulled by Ruby, Tovic and six other dogs. The driver (Tony Phillips, not pictured) rides standing on the runners at the rear of the sled. Microbes and other supplies like food and water travel in the red bag, which is tied inside the sled's "basket."

The basic idea is to subject a collection of benign microorganisms to some of Earth's harshest environments, including geothermal vents, high mountain peaks, and even the South Pole. After the microbes have been exposed to these severe conditions for a period of time, we will recover them and distribute them to classrooms. Grade school students can perform simple laboratory protocols on their samples to see how their microbes fared, and they'll be able to compare harsh environments on Earth to places like Europa, the Moon, and Mars.

The first phase of Life on the Edge was conducted as a joint effort between NASA and the University of California's White Mountain Research Station (WMRS). The WMRS maintains four research facilities for high-altitude research in the White Mountains of eastern California. The highest facility sits atop the White Mountain summit, a wind-swept peak at 14,249 ft. Conditions there are severe. Near the summit air pressure is only 600 millibars and the sustained temperature during winter is a frigid -20 C. Annual precipitation is less than 12 inches, most of which arrives as snow in winter. The temperature, pressure, and low humidity are similar to conditions at Earth's south pole during the austral summer.

"We haven't yet made it to the top (at 14,249 ft.) despite 4 trips with the dog sled team," says Dr. Tony Phillips, a NASA-supported astronomer and musher. "We've been delayed by severe storms, white outs, minor injuries to me and to the dogs -- you name it. It's an extreme environment up there. That's why it's so difficult."

"But," he continued, "we have conveyed the microbes to a summit at 13,000 ft, not far from the 14,249 ft. peak, and they are exposed to the the environment there. We're planning additional trips in the near future to move them to the top."

Some of the yeast packets will be recovered in May for distribution to classrooms. Others will remain at the top through the winter of 2008-2009 for prolonged exposure to severe conditions.

What's it like dog-sledding in the White Mountains?

Tony Phillips contributed this account based on his most recent trip:

Blondie's Revenge
"My dog ate the microbes!"

Feb. 25, 2008: "My team of eight Siberian Huskies and I began a 50 mile sled run to the summit of the White Mountains on a perfect day for sledding. It was cold, the trail was well-packed, and we began our steep ascent averaging about 6 mph. We had previously advanced the yeast packets to 13,000 ft, only 1000 ft below the summit, and this time we hoped to reach the top."

"About 13 miles into our trip one of my sled dogs -- a giant, enthusiastic puller named Blondie -- twisted his leg. The usual procedure when a dog is hurt is to bundle him into a bag which sits in the basket of the sled. The rest of the team then pulls the musher and the injured dog to safety."

"With this in mind I unsnapped Blondie from the gang line, and lifted him into the sled bag. Or tried to. The rescue quickly turned into an epic wrestling match. Although I am twice as heavy as Blondie, and arguably smarter, it was no contest. After a brief struggle, the sled was over-turned, my face was covered in snow, and Blondie stood panting happily back in position with the rest of the team. Blondie wanted to pull, not ride. After a few repetitions of this procedure, Blondie won out. I returned him to the team, and we headed for home."

It was not a very productive trip, except for Blondie who proved that he can pull just as hard on 3 legs as he can with 4."

Feb. 28, 2008: "Two days later we made another assault on the White Mountains. Blondie, who was still limping slightly, stayed home and was replaced in the team by Peanut, a small female Husky. Blondie was clearly affronted by being left behind, but we couldn't risk aggravating his injury. In retrospect I wish I had taken him. I might have avoided the revenge he exacted days later."

Spotless Sun (lote2, #2)
The "sled dogs of science" dash across a steep slippery snowdrift.

"This run began much like the last. A hard-packed trail. A cool breeze. Good conditions for sledding."

"At first we made record time. The dogs ascended 2500 feet in only 2.5 hrs. It looked as if we would reach the summit in a single day with energy to spare."

"Since our last run the wind had blown enormous snowdrifts along the trail. At one point, where the underlying path was carved from the side of a mountain, the trail disappeared entirely under a drift of rock hard snow that spilled steeply downward into a 150 ft ravine. The trick was to make it across without slipping sideways down the side of the mountain."

"From a distance it looked sled-able. No problem, I thought, if we go fast enough."

"We went fast, all right, straight down to the bottom of the crevass."

"Regaining the trail was not easy. The snow was so hard that I couldn't punch my fingers through the surface for a handhold. (They are still swollen from trying.) The only way up was by crawling crablike on my stomach, pulling the dogs and sled behind me. The dogs helped as much as they could, but on the slippery slope they couldn't stand up for long. One, two, then three legs would slip, followed by a funny little "ufff" sound and a downward tug on the sled. Our ascent back to the trail lasted more an hour."

"Once up, I nearly fainted. Then I nearly barfed. It would've been a good workout at sea-level, but at 11,500 ft it felt about midway between devastating and catastrophic."

"We eventually discovered a detour and continued sledding, but the damage was done. We were three hours behind schedule and the exertion of our adventure in the crevass had given me a serious case of altitude sickness. By 4:30 p.m., ill and exhausted, I decided to stop for the night at Barcroft Station (elev. 12,500 ft)."

Spotless Sun (lote2, #3)
The dogs take a breather at the White Mountain Research Station's Barcroft Facility at 12,500 ft. The NASA trailer in the background is part of a NASA/JPL atmospheric research project.

"Altitude sickness is no fun, and I won't belabor the details. Throughout the night I melted snow for cup after cup of herbal tea (my wife's special remedy) and, miraculously, I was fit to sled again by morning."

"On the morning of March 1, I hooked up the dogs and we left Barcroft Station for a stopping point at 13,000 ft where the yeast has been exposed to the harsh mountain environment for over 5 weeks."

"Rather than convey the yeast from there to the summit, which I felt was beyond my limits at that moment, I decided to photograph the area and to collect snow and soil samples for later microbial analysis. At present no one knows which, if any, indiginous microorganisms live in the wind-swept peaks of the White Mountain range. We hope to find some that might later be identified as local extremophiles."

"I spent over an hour collecting samples, including rocks, snow and soil. I packed them carefully into the sled bag, turned the team around and finally headed home."

"Descending from 13,000 ft to 8,500 ft was easier than the climb the day before, and we reached my truck before nightfall. It had been a difficult two-day journey, but I felt that the many microbe samples tucked away in my sled bag made the trip worthwhile. I drove home, tired but satisfied."

March 2, 2008 -- Blondie's Revenge: "A day after we returned I was preparing to ship our hard-won samples to the Marshall Space Flight Center where astrobiologists would examine them for evidence of microbial life. Blondie, still recuperating from his injury, was asleep in my office when I placed the sample bag on my desk and left briefly for a cup of tea."

"When I returned only Blondie remained. The sample pouch was on the floor in shreds. Fragments of plastic vials and swirl bags littered the floor. Blondie stretched and let out a long, satisfied belch."

My dog ate the microbes!

"Blondie is recovering nicely so we know that any White Mountain extremophiles are not pathogenic to Huskies. In fact, Huskies may be the toughest extremophiles we encounter during the Life on the Edge experiment."

"We're going back again in two weeks for more samples. This time I plan to take Blondie with me."