The Garden World of the Northwest Shore

The northwest “finger” of Laguna Negra can be seen near the center of this Goolge Earth image of the region. In the lower left, Laguna Lo Encañado is visible. Credit: Image ©2011 GeoEye/DigitalGlobe/Google; Data SIO/NOAA/U.S. Navy/NGA/GEBCO

by Henry Bortman

So far, our activities have focused on the waters along the southern shore of Laguna Negra, with occasional side trips to Laguna Lo Encañado to collect samples. But yesterday, for the first time, PLL team members Liam Pedersen and Chris Haberle struck out in the battery-powered Zodiac, Mariner 1, on a 40-minute, 4-kilometer journey to the northwest shore of the lake.

There, they discovered another world.

Laguna Negra is only 1.5 kilometers wide, but it is 6 kilometers long, the longer direction running north-south. The lake has two long “fingers” that stretch north, one to the northwest, the other to the northeast.

PLL Base Camp is situated at the center of the southern shore. The Echaurren glacier, however, sits high above the northwest finger. The team has been anxious to do research in this area, because it is where interaction between the glacier and the lake is likely to be greatest. That also makes it an ideal spot to consider as a summer home for the Planetary Lake Lander.

What a difference a few kilometers makes. Upon approaching the shoreline, the PLL advance team spotted underwater caves with denser vegetation than the scraggly assortment of plants along the southern shore. Then they saw the streams, lined with lush vegetation, and displays of wildflowers. And the massive waterfall, Victoria’s Cascade, named by the expedition that explored the area a century and a half ago.

Mariner 1 (the small red dot near the bottom center of the image) sets sail for Hangnail Cove, on the northwest shore of Laguna Negra, below the Echaurren glacier. Credit: Trey Smith)

Most importantly, though, from a scientific point of view, was the turbidity of the northwest water where the waterfall meets Laguna Negra. Most of the lake is crystal clear, which makes for lovely sightseeing, but an indication that the lake is nutrient-poor. As a result of global warming, the glacier in recent years has retreated to a great extent. There is no longer any direct contact between the glacier and the lake. And the water that spills down into the lake from the melting ice no longer carries much sediment. It is that sediment that makes lake waters cloudy. It is also that sediment that carries nutrients for life.

There is a small area on the northwest shore where this turbid water can be seen diffusing into the lake, but because it’s colder than the lake water, it quickly sinks to the bottom, mixing very little with the otherwise transparent lake.

Liam Pedersen, seated near the point where the thundering Victoria’s Cascade pours glacial water and sediment into Laguna Negra, conducts a promising test of communications between the lake’s northwest shore and PLL Base Camp on the south shore. Credit: Chris Haberle

It is just this interaction between the glacier and the lake, however, and the difference between this area, which can support a distinct ecosystem, and other parts of the lake, that makes it scientifically appealing – and a potential long-term site for the Planetary Lake Lander.

Fortunately, communications tests conducted between the northwest-shore landing site and PLL Base Camp were successful, making the prospect of situating the lake lander there for the summer even more promising.

Biology under Stormy Skies

Storm clouds that built up over Laguna Negra for several afternoons in a row sent the PLL team indoors. Credit: Henry Bortman

by Henry Bortman

The weather has taken a turn toward the dramatic. For the first few days we were here, the sky was practically cloudless all day long. Then for a couple of days, puffy white clouds would build up in the afternoon. But in the past couple of days, the afternoon sky has gone dark, we’ve heard thunder in the distance, and the peaks of the mountains that surround the lake have been obscured in mist.

And it snowed. Not down here in base camp. Here we got a half an hour or so of light rain. But up on Cerro Echaurren to the north and even more so on Meson Alto to the east, there are new dustings of white powder. That may not seem odd to those of you reading this in the northern hemisphere, where winter is approaching. But here below the Equator, we are only two weeks from the first day of summer.

Although some of us would prefer to sit on a rock overlooking the lake, listening to the wind and watching cloud formations roll through, the threat of thunderstorms has sent us scurrying to zip up the rain flies on our tents and has forced most of our activity indoors. It has also put a temporary halt to biological sampling on the lake.

Before the storms moved in, researchers collected samples and took measurements along the shore of Laguna Negra. Here Luis A. Rivas (l) monitors the temperature and other physico-chemical properties of the lake’s water. Commodore Chris Haberle has his hand on the tiller. Credit: Henry Bortman

But biologists are dedicated lot, and some members of the PLL team have plenty of samples, collected when the weather was better, that need to be filtered and prepared for laboratory analysis. This process involves sucking up water, liters and liters of water collected from Laguna Negra and Laguna Lo Encañado, into a syringe, some 50 milliliters at a time, and then forcing the water through a small circular filter laced with pores tiny enough to trap microbial cells.

The water gets discarded, except a small volume that will be use for measuring dissolved cations and anions. Also of interest is the yellowish-brown stain left behind on the filter paper, comprised largely of microorganisms from the lake.

Some of these filters are preserved in ethanol, for later DNA extraction. Other filters are kept on dry ice until they can be transported down to Santiago de Chile University, where they will be freeze-dried for the trip back to Madrid, Spain.

Madrid is where microbial ecologists Yolanda Blanco and Luis A. Rivas work, at the Centro de Astrobiología. They are part of a team that for the past several years has been developing a life-detection device, a device they hope will be sent one day to Mars, or perhaps to other worlds in our solar system, in search of evidence for extra-terrestrial life.

In the biological dome, the collected samples are proccessed and analyzed. Here, Yolanda Blanco is sonicating the biological material trapped on one of the filters. Credit: Henry Bortman

The device goes by the name SOLID (Signs Of LIfe Detector), which includes an antibody microarray in its sample analysis unit. This microarray crams hundreds of microscopic dots, each a distinct biological probe, onto a small glass slide. The dots, printed onto the slide, contain antibodies. Some of these antibodies react to specific types of organisms. Others react to common biological molecules, such as amino acids, the building blocks of proteins; or the lipids found in cell walls. Unlike past life-detection methods that look for biosignatures by heating a sample to high temperatures and sniffing at the released gases, the antibody-microarray approach is less destructive, more precise and capable of searching for hundreds of different biosignatures simultaneously.

The array is exposed to a sample, such as the material trapped by filtering water from Laguna Negra. If the organism or biomolecule that a particular antibody is designed to detect is present in the sample, the antibody binds to the sample material. This captured material is revealed by using a fluorescent probe. Examined under the right type of light, these fluorescent tags appear as glowing dots. The position of the dot on the glass slide tells researchers which organism or molecule has been detected.

Blanco, Rivas and their colleagues previously tested detectors at Rio Tinto, in Spain, and in Chile’s Atacama Desert, each time with a slightly different emphasis tuned to the environmental conditions of those field sites. One focus of the work at Laguna Negra will be looking for psychrophilic, or cold-loving, organisms.

Beach Blanket Laguna Negra

by Henry Bortman

La Playa, the gravel beach on the southeast shore of Laguna Negra, as seen from PLL Base Camp. Credit: Henry Bortman

The Lake Lander now successfully moored offshore and mostly operational, PLL Principal Investigator Nathalie Cabrol declared a much-needed day off. Some of the team continued working, anyway. Several of the biologists on the team, scheduled to leave the following day, continued to collect water samples from Laguna Negra and Laguna Lo Encañado and to prepare them for the journey back to their laboratories.

But others took advantage of the brief holiday to indulge in a morning at the beach.

From a distance, La Playa, just east of PLL Base Camp, with its pristine blue-green water and its arc of tan-colored sand, looks like a stretch of shoreline you might find in the Caribbean. Close up, however, what strikes you is that there is hardly any vegetation. Or shade. And that the glacier-fed water, rather than tropically warm, is instead so cold no-one spends more than a minute immersed in it without a wet or dry suit. And that what appears from a distance to be sand is actually coarse gravel.

But still, when you have a day off, and the beach is beckoning, a short walk away, you make do. Here are a few images to give you a feel of the outing.

A motley assortment of PLL revelers enjoy their day off. Left to right: Liam Pedersen, Nathalie Cabrol, Chris Haberle, Henry Bortman. Credit: Claudia Perez

Blog author Henry Bortman attempts to practice his freestyle, but the chilly waters of Laguna Negra, which make relaxation near impossible, encourage bad form. Credit: Claudia Perez

The lake not only serves as a source of recreation, but is also the only place around to do laundry (biodegradable soap only). Here, Liam Pedersen (l) and Chris Hablerle wring out a pair of Liam’s pants. Credit: Claudia Perez

Launching the Lake Lander

PLLers (l to r) Trey Smith, Geoff Saville, Liam Pedersen and Chris Haberle celebrate the successful application of wire and plastic tie-wraps to the task of securing the guts of PLL’s profiler to its pontoon. Credit: XenoQuest Media

The Planetary Lake Lander is a reality! Yesterday it was assembled at Launch Point on the southwest shore of Laguna Negra, and today it was sailed to its initial mooring point about 100 meters offshore, near PLL Base Camp. Major accomplishment.

The lake lander has four main components. The pontoon is the floating platform to which everything else is attached. The sonde is a package of underwater sensors that can be lowered to different depths. The weather station measures temperature, barometric pressure, wind speed and direction. Finally, there is the profiler. It contains a winch to lower and raise the sonde, a package of electronics to collect and store data, and radios to transmit that data to PLL scientists.

The sonde has a number of sensors on it, each to study a different characteristic of the subsurface lake environment. It monitors water temperature; pH; dissolved oxygen; conductivity, an indicator for the saltiness of the water; turbidity, or water cloudiness; and the amount of algae present.

Every hour, the PLL profiler sends commands to the sonde to descend through the water column, collecting data as it goes. For now, this data gets sent to the Robo Dome at Base Camp. Beginning in a couple of weeks, once the PLL team packs up and leaves, the profiler will transmit its information via satellite to NASA Ames Research Center in California.

In prepration for the deployment of sonde Jerry onto the Planetary Lake Lander, Angela Detweiler cleans its environmental sensors. Credit: Henry Bortman

By combining underwater and weather data, PLL scientists will be able to construct a model of how atmospheric conditions interact with subsurface conditions. This model will lay a foundation for spotting events that deviate from the norm.

The model will also enable engineers from the Intelligent Robotics Group (IRG) at Ames to write software that will ultimately transform the PLL from a passive data-collection device into an intelligent, autonomous robot. Their goal for the three-year project is to infuse PLL with decision-making ability so that, without human intervention, it can spot events of particular scientific interest and alter its data-collection routine – taking more-frequent measurements, for example – to study these events in greater detail.

Of note: although the Planetary Lake Lander does not yet have a name, the sonde attached to it does. It’s Jerry. Jerry? Yes, Jerry. It has an identical twin, Tom, which is not tied in to any communications capability and which currently gets moved around from one lake to another at the whim of scientists. While Jerry will spend the summer ascending and descending through the water column below the PLL platform, its information relayed back to Ames, Tom will be left in a single stationery position in one of the other nearby lakes, collecting data through the summer but unable to share what it learns until someone comes to retrieve it.

On his homemade vuvuzuela, Liam Pedersen (seated in chair) trumpets the arrival of the PLL at its temporary mooring site near PLL base camp. With him are Trey Smith (standing) and Chris Haberle. Credit: Henry Bortman

Also of note: The PLL is currently “parked” offshore near base camp, not because it is the most interesting spot in Laguna Negra, but rather because it’s easy to get to in case repairs need to be made. Later this week PLL team members will begin scouting the northern side of the lake, searching for the ideal spot for PLL’s summer home.

Oh, and still no shower, but we finally have a bathroom.

Quote of the day: “One real downside of our current dinner setup is the lack of portion control.”

A Close-up Look below the Surface

A engineering drawing of the Titan Mare Explorer craft proposed as a future NASA mission. Credit: Proxemy Research

One of the goals of the Planetary Lake Lander Project is to develop technology that could be applied to a future mission Saturn’s giant moon Titan.

The Titan Mare Explorer (TiME) mission, proposed by Ellen Stofan of Proxemy Research, in Rectortown, Va., would land an autonomous spacecraft on and sail across one of Titan’s methane lakes, capturing photographs and taking measurements both above and below the lake’s surface. This proposed mission is one of three funded for further design development as the next possible NASA Discovery mission.

Over the three-year course of the PLL project, engineers will develop a floating robot with capabilities similar to those that will be required by TiMe or a similar mission to Titan. The Planetary Lake Lander will be able to respond autonomously to scientifically interesting events in the rapidly changing glacial-lake environment of Laguna Negra. Robotic autonomy will be important to any Titan mission because Titan is too far from Earth for scientists here to receive data from a spacecraft on Titan and to respond with real-time commands. A robot exploring one of Titan’s lakes will need to operate on its own.

But for the first year, the Planetary Lake Lander will be under human control. It will remain behind at Laguna Negra when the PLL team leaves in mid-December, deploying a package of instruments that for a three-month period will continuously monitor conditions above and below the surface of Laguna Negra, sending its data, on demand, back to engineers at NASA Ames Research Center.

David Wettergreen tests his prototype underwater microscopic camera along the southern shore of Laguna Negra. Credit: Henry Bortman

Onboard the PLL during this initial 3-month stint will be a 5-megapixel camera, remotely controllable; a meteorological station to track weather conditions through the summer months; and a sonde, a package of instruments for measuring water temperature, salinity, pH and other lake-water characteristics at various depths.

Future posts will report on the deployment of the pontoon (the floating platform) and the instruments that will be installed on it. But all this was not yet in place in the early days of the PLL field season. What did get tested early on, briefly, was a microscopic underwater camera designed to give a very close-up look at what’s lurking beneath the surface of Laguna Negra.

David Wettergreen of Carnegie Mellon University in Pittsburgh, Pa., made a quick stop at the PLL base camp today to try out the camera, which lives inside a watertight metal housing. The 15-micron-per-pixel camera can see extremely small details: a single human hair appears 8 pixels wide.

The good news: the underwater test worked. The not so good news: mostly what it saw was bubbles. Not even a lonely copepod ventured by during the test. Later, however, back on shore, Wettergreen pointed the camera at a small plastic bottle filled with copepods from the lake, and beautifully detailed images of the tiny swimming crustaceans sprung to life.

The underwater camera will not be part of the instrument package deployed on the PLL at the end of the first field season, but it will be integrated into the PLL in future years.

After a few days of clear blue skies, clouds began building up in the afternoons. The gravel beach in the lower right, a short walk from base camp, has been dubbed La Playa. Credit: Henry Bortman

Meanwhile, on the quality-of-life front, still no shower. Or bathroom. There are workarounds. Instead of a relaxing, warm shower, a quick jump in the freezing cold lake does wonders. For the faint of heart, pouring a bottle of water over one’s head also works. As for the bathroom, if you’ve ever gone backpacking…

Quote of the day: “Ve haf vays of making ze radios talk.”