Oct. 22nd, 2002

Andy Hock

The following update was given by Andy Hock. Even though this update was made before the expedition, we thought it was important to show this because David Fike and he were testing the instruments in the lake, as the pictures will show. Today was our first day of science, where we studied ancient lake shorlines, we studied the effects of UV radiation on organisms, and tested water samples. The pictures show the plexiglas and water sample experiments.

We’re getting warmer…T minus 2 days until departure, and I’ve just finished constructing and testing ‘Bonnie’ and ‘Clyde,’ a pair of very sensitive thermal probes. Thermal probes? Yes. Here’s the idea: we have a team of scientists traveling, hiking, to the world’s highest lake. We’re exploring it because it’s a unique, extreme environment on Earth. We’re exploring it because it has some exciting similarities to environments we think1) may have existed on Mars in the past, and 2) could have supported life. We’re exploring because it is part of our nature.

My role on the science team is to help characterize the physical environment of the lake and to see if the lake is heated by geothermal energy—by the volcano. Some observations: the deep water of the lake is warmer than one would predict and there is an abundance of life in this otherwise desolate place...Is there any connection between these two? Could it be that the volcano is supplying energy to keep the lake warm and support the biological community? To help answer this, I designed two probes—partners in crime—that I’ll use to measure the amount of heat coming from the volcano in to the bottom of the lake and the temperature of the lake bottom sediment.

Building my instrumentation is the topic here, though, and that’s never as simple as it seems: when I first began thinking about this experiment, I was sure that I could simply purchase something, plug it in, and come down from the volcano with great data. As it turns out, off-the-shelf instruments that are 1) accurate enough to read out very small heat flow values, 2) light enough to carry up a volcano on your back, and 3) cheap enough for a graduate student budget just aren’t around. So, I had to design and construct new instrumentation to fit my needs. The pictures along the side show my adventures for the last couple of weeks as an astrobiologist-turned-engineer. Our computer lab turned in to a machine shop and I was busy sawing and welding instead of typing.

Basically, what I came up with are two short metal arrows that I can dive down in to the lake with and push down through the soil. When I resurface, one of the team members on the boat will be able to measure the bottom temperature or the amount of heat flow in to the bottom of the lake with a very sensitive handheld meter. The probe itself is made of aircraft-grade aluminum, ceramic cement, and silicone water sealant (to make the entire thing waterproof). It measures very small temperature differences using a bundle of 100 very fine wires, welded by hand, by yours truly.

After making these measurements, we’ll first see if the lake is being heated by the volcano, and second try to understand the kinds of conditions life may have had to endure in similar (volcanic lake, hot springs, etc.) environments on Mars and target future astrobiology missions along this path.