Sunday, April 8, 2007

March 28, 2007: Day 3

Today was the only day that hasn’t been filled with activities to sign-up for. The reason why was that it was media day and most people were involved with the event. You would think that that, would make it a good day to sleep in, but several of us got up at 4:00 in the morning. Our plan was to do some exploring on our own. Zzyzx is an oasis on the edge of Dry Soda Lake. Soda lake is a dry lake bed that extends for a couple of miles to the east and northward towards the town of Baker. To the west, is a large range of mountains that extend northward from Zzyzx. At the end of the range overlooking Zzyzx, is a peak called Mt. Springer. Several of us decided we would get up early and climb it. Why risk out lives climbing in the dark with headlamps and flashlights? It wasn’t to avoid the hot daytime sun, but to make sure we returned in time for breakfast. It turns out that the camp cook was outstanding and no-one wanted to risk missing breakfast at 7:00.

We met in the parking lot. The sky was dark, but sprinkled with more stars than I had ever seen in my life. It is true that desert skies provide an amazing view of our universe. The mountain itself was only a black outline before us, its boundaries only distinguishable by the sparkling stars.

We started out climbing a spur of hill that jutted out towards Zzyzx. In the dark, with a flashlight in my hand, all I could see was the boulders in front of me and the beams of the other’s headlamps. In a way, it made it easier to climb because you couldn’t tell how far down the slopes were around us. The climb up took about two hours and was over 1000’. At the top, there were several cairns and a weather station. One of the cairns had a cross in it and ammo can at its base. The can held a logbook and items left by others who had been there.

A little after six, the sun began to show over the mountains to the east. The view was spectacular. From our high point we could see the valleys and desert all around us. Ten miles away we could see Baker and the line of traffic coming and going from Las Vegas. Below us was Zzyzx. It was also much cooler at the top, as we had been protected from the breeze by the mountain. At the top though, the wind was strong and the sweat on our backs from our climb, quickly chilled. After pictures and signing the logbook, it was time to head back down. We could take the long route down the ridge, or go straight down a ravine on the face of the mountain.

We split up, with some of us taking the old route and some of us going straight down the face. I went down the face which ended up being much more challenging than I expected. We had to lower ourselves from ledge to ledge, which during a rain would have been a series of water falls. It took us around an hour to get back to Zzyzx, getting us back in time for breakfast.

After breakfast and a little rest, we had until the afternoon before we went back out into the field. I went and watched the end of the English version of the web cast and spent some time in the lab. Another group heard about us going up the mountain and they wanted to give it a try too, so we met again at 10:00 and decided we would climb for an hour and then return for lunch. My legs were tired, but we made it about half way up to where the spur connected with the ridge. Even half way up, it was still a spectacular view of dry Soda Lake and the desert.

While the day was not full of planned scheduled activities, I found it one of the best only because it was true exploration. It was the chance to wander and see what we wanted and go to whatever caught our eye. That is what I need to get my students involved in, some form of exploration where they learn on their own and go where their interests take them.

Wednesday, April 4, 2007

March 27, Day 2

Day 2: March 27, 2007

Today we drove back out to the Cima Lava field. The goal for today was to explore desert soils and how desert pavements form. Desert pavements are the rocky surfaces that form in deserts. The original theory was that light soils were removed by the wind leaving the heavier rocks and pebbles behind. This process is called deflation and does occur in some areas. Over time, a layer of rocks and pebbles form a crust over the desert floor that looks like a gravel parking lot. New evidence shows that these pavements actually may be forming by a wetting, drying cycle. Instead of the wind removing light soils, the wind actually deposits dust over the lava fields. The dust works its way down into the spaces between the rocks. When rain occurs, it soaks down into the dust deposits causing them to expand and swell, lifting up the rocks around them. Over time the rocks and pebbles float to the surface and the soils build up below them. The older the desert pavement is, the deeper the soils will be below them.

Desert Pavements occur on Mars, so by understanding the processes here on Earth, we can get a better idea of how soils form on Mars. We tested the soils at lava flows of different ages for the amount of organic material they contained. The hypothesis being that the older the deposits the more organic material they would have. On Mars, a rover could dig a few inches below the desert pavement and test the deep soils for evidence of life.

We also tested the ancient soils below the lava flows. These had been capped by the lava and should give us a good idea of what the soils were like in the past.

The last thing we looked for was iron minerals in the soil. Iron has been found in the soils of Mars, but different minerals form under different conditions. Some iron minerals need water to form, such as hematite, others do not need water, but higher temperatures. By looking at the minerals in the soil around the lava flows and below the lava flows, scientists can get a better idea of how they form. These results can then be used on Mars to determine the conditions that may have been present there.

Our day had to end a little early. A very rare cold front came in with rain, dust storms and snow.

Tuesday, April 3, 2007

March 26th The first day in the desert.

March 26th: Day 1 in the Mojave

On my first day in the Mojave, we took a geologic tour of the region looking at Mars and Lunar analogs. Our first stop was at some stromatolite deposits. This deposit was about 1.6 billion years old and is some of the earliest evidence of life on Earth. Stromatolites are dome–like structures formed by algae. The algae build up in layers over time, forming domes in the shallow seas. Evidence suggests that similar shallow seas may have existed on Mars. A robotic expedition to one of these areas on Mars would be looking for similar dome-like structures ifor evidence of life. At this site, we also learned about desert varnish. Desert varnish is a dark shiny layer that forms on the surface of rocks in desert environments. The layers are usually made of manganese or iron oxides. These layers do not form from the rocks themselves but are deposited on them. The question is by what? Bacteria are present in the desert varnish and some evidence suggests that the bacteria are depositing the oxides as part of their biological processes. This is important because similar varnishes may occur on Mars. If desert varnishes on Earth are biological, then that could be evidence for life on Mars.

Our next stop was the Cima lava flows. These flows range from 500,000 years old to 10,000 years old. What we were observing was their structure and similarities to flows on the moon and Mars. On Earth, over time, gaps in the rock that forms the lava flows fill in with wind blown deposits forming a layer on them that looks like pavement. The older lava flows look very much like the surface of Mars except for the occasional plant. Standing on a lava field, you can easily imagine yourself looking at the surface of Mars.

We then drove up closer to the cinder cones that formed during the same period as the lava flows. Cinder cones are also seen on the moon and Mars. Near the cone was a collapsed lava tube. Lava tubes form by the surface of the lava hardening into a crust, as the lava continues to flow below the surface. Once the lava flows out from under the crust, a hollow tube is left. Sometimes these tubes collapse forming snake-like valleys. These valleys are also known as rills, and can be seen on the moon and Mars. Sometimes just small amounts of the lava tube ceiling collapse forming skylights to the surface above and providing some light within the lava tube.

Lava tubes are important for space exploration for several reasons. The may provide protection for life from ionizing radiation and could also be used as habitats on the moon and Mars to protect astronauts. Instead of transporting heavy protective habitats to the moon and Mars, astronauts could take advantage of the protection provided by the lava tubes.

One of the experiments conducted was to locate lava tubes by remote sensing. Using an IR camera in a hot air balloon, scientists looked for the temperature differences between openings to the lava tubes and the surrounding rock. In the morning the openings were warmer than the surrounding rock giving distinct differences on the camera. In the afternoon the cave openings were cooler than the surrounding rock making them visible on the camera. Probes orbiting Mars could use similar techniques to identify lava tubes and caves. Later, robots designed to enter the caves could explore them for scientists. We tested some robots in the lava tubes to get ideas for future designs