Friday, March 30, 2007

Day 3: Stromato-whats?!?

[Sunrise over the Mojave]

(Ed: I've enabled comments from you non-Blogger members, although I get to moderate them to make sure you're not a spammer)

Wednesday was Media Day here. There were two webcasts scheduled for the morning. One in Spanish, one in English. Since many of the teachers had friends, family and students tuned in, there were only a couple of scheduled activities. Luckily one of them was the chance to play with a robotic rover. Now the rover that they had brought was nothing like those currently on Mars, and far less capable than the next generation rover. This one is based on an off-the shelf robotics kit, costing a "measley" $5000. The idea that Dr. Maite Trujillo was working on is to use the far less expensive rovers for "canaries" once the manned colonies on the Moon and Mars are occupied.

Since the rover is remotely operated, it can be sent out as an explorer to scout new areas, or to take simple readings, in lieu of a more expensive robot or Human explorer.

The rover also uses a standard external peripheral bus (USB), which means that a whole suite of different sensors, tools and other goodies could be attached on an as-needed basis. For our trials, the rover was only equipped with a USB camera as its sole sensor.

Our session with the rover team was realy just an introduction to tele-operated robotics, a chance to see a system in operation, and also an opportunity to see how such things can go wrong. The rover used a standard 802.11b network, which lost connection several times due to the construction of and locations of the buildings. Each of the four team members took a turn at driving the rover and trying to steer it toward a goal. I tried to drive it onto the back porch, and into the middle of the Spanish webcast (where Maite was about to be interviewed), but was foiled by the thickness of the building walls.

After lunch, I took advantage of another ad-hoc group. If you remember, the last one was Monday, when I hooked up with Jud and Mike, and had an absolutely awesome time setting sensor packs in the caves. This time, Dr. Rafael Novarro-González needed to take a small group out to a number of geologic sites to retrieve samples of stone and rock in order to compare mineral content to other samples he had taken in the Atacama, Rio Tinto, in Spain and several locations in Antarctica among others.

Our first destination was a field of stromatolites, located above an abandoned talc mine in a band of sedimentary upthrust. We had a bit of a drive, and I was in the back seat of a van full of spanish-speaking scientists. If you think sitting in a room full of scientists results in unintelligible conversation, try one where they are all speaking another language. My two years of high school spanish was far outclassed...I took a nap. ;)

I awoke to the now familiar feel of a bumpy, gravel road, and the sight of the bright white tailings of an old talc mine. The mine was a short hike from the road, so with our approximate directions for the location of the stromatolite field, we set off bravely for the stromatolite field.

Note how I used the word "approximate" to describe our knowledge of the field...That's right, only one of us had been there before, and he was just part of one of the previous trips, not a guide. We found the mine pretty easily, but the field eluded us. Ready to admit defeat, we headed back to our van.

Once again, luck played a hand. Rafael remembered that he had a set of pictures of the field and its location. Breaking out his files, we were able to place the field relative to the mine, and made the trek to the mine, once again. In this case, I didn't complain about the hike, because with all I had learned over the last few days, I was walking through an incredible variety of desert pavement, varnish, lava and other interesting geologic fields, as well as enjoying a beautiful, cloudless afternoon.

We got to the field, and they were everything I had hoped to see.

For those of you who have been thinking "Stromato-whats?!?", stromatolites are a combination biologic and sedimentary structure. Mats of cyanobacteria (formerly known as blue-green algae), grow in a shallow ocean or pool. Occasionally, a thin layer of sediment will be deposited on top of the mat. Since cyanobacteria is photosynthetic, the majority of the covered mat will die off. However, enough of the cyanobacteria survive to begin re-forming the mat, on top of the layer of sediment. Since the sediment is not deposited evenly, the new mat has more of an uneven appearance. The process repeats many, many times. Over thousands of years, layer upon layer of alternating sediment and mats build up a field full of small "towers". These towers are stromatolites.

The picture of my two samples show how a flat mat slowly changes into a mounded structure. The effect is most obvious in the sample on the left.

The field was located in an area where we were allowed to take samples, and I was lucky enough to grab the two you see above. The two came from different strata, separated by about 20 feet in vertical direction, and probably several million years (at least) in age. The one with lighter sediment comes from the older strata, the gray sediment comes from the same as the main field that we came to see.

The fossilized field in the rock strata has a very well defined layer where the thick, dark, iron-rich material was deposited on top of a field of stromatolite towers. You can see the obvious horizontal band, outlining the rounded towers in this picture.

Stromatolites are important, because they provide our most early fossil evidence of life on our planet. This particular field is between 1 and 1.5 BILLION years old. There are many other stromatolite deposits worldwide, that are older. The earliest fossils of other life are half that age or younger. The earliest dinosaur fossils are about a quarter the age of the stromatolites we were looking at.

With our little "approximate" location error, we weren't able to visit other sites that afternoon, but it was still another winning day!

Thursday, March 29, 2007

Day 2: Mahana!

"The word for the week is 'adaptability'"
So spake Liza Coe, our illustrious leader.

Adaptability works great, lucky happenstance works better. :)

After a short night's sleep, I woke again, before dawn to have enough time for a shower and some personal grooming before breakfast. Having missed the sign ups last night, I took a look to see what was still left. Following my strategy from yesterday, I chose to try the Photosynthesis group's daily expedition. They were planning to head out over the alkalai flats and make some observations on the growth patterns and diversity of the bacterial and microbial life.

Immediately after breakfast, my plans were changed. Four groups, including the photosynthesis group, were being merged into one big "geologic tour" group. Meh - large groups make for little fun, less "face time" and more of a 'tour group' feeling. I hate tour groups.

Luckily for me, I chose to ride with Linda Powers, a researcher out of the University of Arizona, who was here with one of her graduate students, Heather, and one of her company's engineers, Drew. They were using Dr. Powers' creation, an advanced microbial life detector, as a tool for Heather's research into the diversity of life in different types of desert soils.

On the ride out to the Cima Lava Fields, our first site, Dr Powers described her work on "Mahana", and how Heather's thesis work was using the device. They would be gathering sterile soil samples from the various locations we would be visiting with the group. They had no teachers "assigned" to their team, so I volunteered to help. Since we were more or less sticking with the tour group, I got to have the best of both worlds; the geologic tour with Steve Wells, and the sample gathering experience of field research.

Sterile sample gathering refers to the method by which the sample is gathered, not the soil itself. Since Heather is measuring the quantity of bacteria and other biological material in the soil, any external "riders" would skew her data. We had to be sure to use sterilized instruments to gather the samples, sterile bags to store it, and we had to take extra care to not touch the sterilized surfaces of our tools. Our gathering team would take two samples at each location to ensure the quality of each. The samples were carefully labeled with the location, including the GPS coordinates, and the sample taker's initials. Hopefully, they won't be throwing out the ones labeled "ML" :)

In the meantime, Steve Wells told us all about the formation of "Desert Pavement" and "Desert Varnish". Pavement is an odd phenomenon where the surface of the ground becomes covered with many interlocked small rocks. Under this layer are three more layers. The pavement is actually formed by the windblown or aeolian dust, which trickles down between the rocks, forming the underlaying soil bed. When you scrape away the thin surface layer of loose rocks, you will find the most recently deposited dust. Over time, with the scant rainfall and slight pressure from the overlaying material, the dust compresses into tightly packed "peds", or polygonal pads, a few inches per side. Dr. Wells called the ped layer, "Layer A".

As water flows down the edges of the peds, it carries minerals and small amounts of dust, which fill the gaps in the peds, making them even more tightly packed. The rainwater also supplies bacteria in the peds with required moisture and nutrients. However, since the peds are so tightly packed, bacteria is far more prevalent on the edges and in the junction between Layer "A" and Layer "B".

Layer "B" is an older layer, below the first layers, determined by a slightly different chemical composition. The water infiltration in the A Layer leeches out the carbonates and other soluable minerals. These minerals are deposited in the B layer, and deeper underground. The higher carbonate and mineral content of the B layer distinguishes it, making it noticibly harder, and much more reddish in color.

Desert varnish is a biological phenomenon -- possibly. One of the theories for its formation is that a mineral eating bacteria lives on the surface of rocks. It is not all that well understood, but it appears to take iron and manganese from the rocks, oxidizes it, and forms a dark, shiny coating on certain types of rocks. The varnish only occurs in a very thin surface layer, so anything that scrapes or cracks the rocks also removes the varnish. The other explanation is that the varnish is a naturally occuring condition, caused by weathering. The bacteria seen on the varnish just happens to like the oxidized minerals, and thrives better where those minerals are present. As with many scientific fields, the only way to determine which is the better theory is to study the condition, and accumulate evidence to support or contradict one or the other of the two theories.

On several of the rocks, older civilizations have etched patterns and symbols on the rocks. We saw a couple of sets of these petroglyphs. The one on the left looks awfully like a Masonic symbol...

After we gathered several sets of samples for Heather, we headed back to base to start calibration and data gathering with Mahana. Once again, my little Mac proved itself useful.

The output from Mahana's driver software needed to be imported into Excel and have the average/mean and standard deviations calculated. So, I put my ol' Mac to work with some simple data entry and calculations -- Yes, Dr. Kress, I actually created tables and graphs using Excel!

On the camping front, the winds blew in last night, and my "hotel" is still standing. I'm keeping my fingers crossed that it will still be there at the end of the week!

Wednesday, March 28, 2007

Day 1: Sun & Shade

Things are looking up, in many more ways than one. First off, our Zzyzx base camp has a wireless Internet connection, so I should be able to update daily, provided I actually have time, and don't keep coming back to camp after 10pm.

Yesterday's word was "Serendipity". I went with yesterday's thought and chose to bypass the most popular science themes which were the geology field trip, although I definitely want to do it on Thursday, the soil microbiology transsect, and of course, the rover and hot air balloon trips.

Instead, I went with the Soil Metereology team. They only had one person signed up, and they had no "Lettuce Bagger" -- If you're nice and leave me a comment, maybe I'll tell you what that means. ;)

Our task for the day was to set up a meterologic station to monitor weather conditions around a carefully selected area. The purpose is to see how temperature, humidity, wind speed, light exposure and the other ambients affect the soil. Since we want to be able to make a comparison to the dry, desertlike conditions on Mars, we had to find a site with soil most like what we expect to find there. Being in the desert makes our site selection a bit easier than elsewhere, but it was still difficult. Our selection was at the base of an alluvial fan, where a large quantity of wind-blown sand and dust had accumulated. even in these dry conditions, there were still quite a few creosote bushes, and dried grasses. We set up our monitoring station as far from the vegetation as we could, took a few non-sterile soil samples, and returned to our base camp. The research team, led by Dr. Kress and Leo Hernandez will return later in the week to take sterile soil samples and collect the data collection instrumentation.

For all you tech geeks, we set out about twenty sensors of the various types, all connected to loggers. All of the data loggers use either a serial or USB data connection to a computer. Once they are initialized, they will continue to take data, storing it internally, until they are collected, and their data downloaded. The initialization process involves attaching the devices to a computer, having the computer recognize the device, and then set the timers and internal clocks of the devices.

When our group gathered, Leo was diligently initializing the various loggers. I jokingly commented to one of my fellow teachers that whenever you are dealing with new hardware and a computer system, the 3x rule applies. You should figure that the process of getting the hardware up and running should take three times as long as your original estimate. So, when Leo told us it would take a half hour to 45 minutes to prep things, I expected to be in for a bit of a wait.

Leo did his best to prove me wrong, but 90 minutes later, the hardware wasn't as cooperative. One logger just didn't want to talk to his PC - apparently, it needed a special software package, and they had left the disks behind. The only software they had was a Mac version (- insert an editorial pause for those of you who can see the next bit coming -).

So there I was...a software engineer, with 12 years of experience with experimental hardware and Mac systems. I bet I could probably help.

"Hey guys, I have a Mac."

The walk back to my tent to get my laptop took fifteen minutes. The installation of the software took five, initializing that final sensor took another five. Hurray for Macs!

My day was only half over at this point. We had finished setting up the entire soil meterology monitoring station, and it wasn't even lunchtime yet!

It was at about this time that serendipity played a hand. Mike Spilde and Jud Wynne came back from a scouting mission of some potential lava caves. Jud is a part of the team at NASA who have just found several potential caves on Mars. His team is interested in characterizing how thermal and humidic differences can be used to detect the characteristics of caves on other planets. How much does the depth of a cave affect it's thermal signature at the surface? How does the temperature of the cave differ from the surface to its deepest point?

To gain an analog for Martian and other non-terrestrial caves, we want to explore caves in the driest areas of Earth. When Jud and Mike returned, they asked if anyone would be interested in accompanying them to explore some of the more "advanced" lava tubes in the area.

Of course, I jumped at the opportunity.

After about an hour's drive, we arrived in the southern part of the preserve, at a cinder cone, where there were hundreds of lava tubes just waiting to be explored. Mike and Jud handed out all the equipment we needed, helmets, lights, gloves and knee pads. A short walk over the lava field brought us to a tube named "Russel Stewart", presumably after the person to map it. The entrance was a tight, sinuous descent through a jumble of the broken skylight. After we got through the broken rubble, the tube opened up into a large chamber. While Jud placed a sensor pack, Mike gave us an overview of the different mineral formation and biological growths.

Jud needed to place the third sensor "deep" within the cave, so deeper we went. This tube was an easy tube, with just a few places where we needed to get on our hands and knees to duck through tight spots. Jud placed the sensor pack, and we headed out to the next two tubes.

Upper and Lower Glove lava tubes were much more cramped. These two parts of the same tube had retained a large amount of their molten lava after it stopped flowing. When the lava cooled, there was much less space in the tube. After placing the surface and entrance sensors, Jud bravely led our group, deep into the bowels of the lava (well, at least a hundred feet into the bowels), where we placed the final sensors, and climbed back out.

Our impromptu expedition had run late, and dinner was already being served back at base, so we had to improvise. Jud and Mike led us to this little restraunt, right on the side of Route 66, Baghdad Cafe. Apparently it has a starring role in some movie. ;)

When we arrived, the doors were closed, lights out, and the chairs were up on the tables, but Jud, with his classic drawl, convinced his fellow southerner to open the doors for our group of starving researchers. We had an incredibly satisfying meal of American road cuisine - I had chicken fried steak and a couple of Millers - and some great conversation and stories from the owner.

Finally, we rolled back into Zzyzx around 11pm, strategically missing the organizational and administrative meetings.

Monday, March 26, 2007

Day 0: Drinking from the fire hose

Welcome to Zzyzx!

After another night's stay in Mammoth Lakes, I made the drive to our base for the rest of the week, the Zzyzx Desert Research Center.

Today was meant as a travel and very brief orientation day. Nothing was on the official schedule until dinner at 7pm and a mass group meeting afterward. Everyone met together and we were given the do's and don't for the area. The usual, "look out for rattlesnakes, scorpions and nasty bugs" "don't drink the water" etc. We were also treated to a geologic history of the area, including the conditions leading to the formation of the Soda dry lake, where the base is situated.

We were then given the official list of the projects that will be going on while we are here. Talk bout overload! Imagine that you are on a research expedition with several groups of NASA research scientists. Each group presents you with a brief overview of their project, and you have to choose which you will be assisting with. The science geek in me is in Heaven! The "normal" person in me is hiding in a corner babbling incoherently. ;)

It looks like I will be opting for the "sample a bit of everything" after all. There are a couple of research paths (originally called "science themes") which look like they are going to be extremely popular. Doing an infra-red scan of the desert, looking for caves from the hot air balloon seems like it's going to be one of the most written about.

While a hot-air balloon ride would definitely rank high on my scale of "cool things to do", the main goal of the program is to ignite the spark of enthusiasm for science in the young students. Telling them that you can do your science from a hot air balloon, just seems too easy. I'll wait and see what the sign up sheets look like tomorrow morning. The teachers (and the Astrobiology students) declare our interest for the day by signing a sheet, with a limited number of spaces, for whichever "theme" we want to participate.

I know I want to do the microbiology at least one of the days, and the geology trip, probably on Thursday. As for the other days, I'm thinking that I may just pick the sheet with the fewest names on it. That way I'll get more face time with the scientists, and researchers.

As a bit of a bonus, Dr. Brian Day, broke out one of the research center's telescopes, and we spent about 90 minutes looking at lunar features, with Dr. Day explaining how their formation closely mirrors the formation of similar features in our area. If you ever have a chance to have a NASA scientist give you an astronomical tour of the night sky, DON'T PASS IT UP! Even with my experience as an amateur astronomer, I learned almost as much in that hour and a half, as I learned in my entire last semester's astronomy class.

Of course, now it's after Midnight, and I am still typing away in my tent, and have to get up in a few hours. Ahh, the life of a field researcher!

Saturday, March 24, 2007

Day -1: Ice Age Adventure!

A scant hour south of Mono Lake, is the town of Mammoth Lakes, where I stayed the night. Coincidentally, there's this little ski resort located just outside of town. Naturally, I had to investigate. ;)

Not much science, but definitely a bit of R&R before the expedition starts tomorrow evening. I even got to see Devil's Postpile and Yosemite, from the back side. Devil's Postpile is the dark parallelogram about a third of the way up the picture on the right. If you look closely, through the haze, you can also see the back side of Half-Dome in Yosemite, about two thirds of the way up the left side of the picture, past the second range.

Sorry for the small pictures, that's how it goes. You'll have to ask me in person to see the full-size ones!

Now, to head for the hot tub, and get ready for another day of driving tomorrow!

Friday, March 23, 2007

Day -2: Mono Lake

What an awesome way to start my trip!

I woke up bright and early this morning (without an alarm - Can you tell I'm excited?), and hit the road. I made great time, and before I knew it, I was coming over Echo Summit, just in time to see the sun rise over Lake Tahoe. After a brief stop - gotta have my morning Starbucks! - I drove on to my main stop for the day, Mono Lake.

A lot of people know about Mono Lake from the environmental issues in the 70s and 80s. I'm not really going to go into that, feel free to read up elsewhere on the web. It should suffice to say that Mono Lake is recovering nicely, and is an absolute must-see if you are anywhere near the Eastern Sierras.

My interest in Mono Lake, especially as it pertains to Spaceward Bound! is twofold. First is the formation of the tufa towers - those strange, white rocks in the middle of the lake. Since this is an Astrobiology blog, it should be natural to talk about the Carbon/Silicate Weathering Cycle. Atmospheric carbon dioxide reacts with water vapor to form a weak solution of carbonic acid. This acidic rainfall dissolves silicon-calcium rocks, forming SiO2 (the mineral in quartz) and calcium in solution. Normally, this calcium would flow to the ocean, where marine organisms would take it in, add some carbon dioxide, and make shells and bone out of it. The shells eventually settle to the bottom of the ocean, and over millions of years, eventually get recycled into the high pressure/temperature areas in the Earth's crust subduction zones. Those same high temperatures and pressures re-form the compressed shells (probably better known as limestone) into the original calcium/silicon rocks, and release the carbon dioxide, back into the atmosphere through volcanos.

Now, because Mono Lake has no outlet, it relies entirely on evaporation to maintain its level. Which also means that, while the water vapor will evaporate, any minerals that it brings with it stay behind. Mono Lake is extremely salty and alkaline - 2 1/2 times as salty as the ocean, and 80 times as alkaline. This unique chemical (im-)balance means that Mono Lake doesn't need marine organisms to precipitate out the dissolved calcium from rainwater. When underground springs, carrying the calcium flow out into Mono Lake, under the surface, the calcium immediately reacts with the bicarbonate in the water, forming the limestone towers. Although these can only be formed underwater, because Mono Lake's level has fluctuated (it's 25 feet below its 1941 level, and over 900 feet shallower than its peak depth after the last ice age), many of these tufa are now visible above the surface.

The second reason I wanted to visit Mono Lake is to see all the volcanic formations in and around it. The two major islands were both formed by underwater volcanic vents. Paoha Island remained underwater, after its eruption, and was partially covered in a layer of tufa. Negit Island (and Black Point - which was an island when the water level was about 400 feet deeper), rose above the surface of the lake before it could be covered in tufa, so it is much darker.

My real adventure for the day came when I stopped off for a hike around Panum Crater. About 650 years ago, Panum Crater was an active volcano. Today it lies dormant, and you are able to walk around the rim, into the crater, and onto the lava dome in the center.

This picture shows one side of the lava dome and you can just barely see the rim of the crater curving around behind the dome in the right of the picture. The crater is an amazing assortment of volcanic rocks. Around the outer rim is a mixture of crushed light pumice, obsidian flakes and an occasional small piece of Rhyolite. All three of these types of rocks have similar chemical composition, but vary vastly in appearance due to how they were formed. Obsidian is formed when volcanic lava, containing very little dissolved gasses (like the carbon dioxide from the carbon cycle above!) cools quickly. Pumice, the very light, porous rock, is formed when the same type of lava contains lots of dissolved gas and cools quickly, trapping the gas bubbles. Rhyolite is what forms when the same lava cools slowly. In this case, any dissolved gasses have time to escape. In addition, because the lava is cooling slowly, crystals of quartz (SiO2), plagioclase (combinations of NaAlSi3O8 and CaAl2Si2O8) and feldspar (combinations of KAlSi3O8, NaAlSi3O8 and CaAl2Si2O8) have time to form.

What made my day completely cool was a lucky stop by the Lee Vining Chamber of Commerce/Visitor's Center and a chance encounter with an Inyo State Forest Ranger. When I mentioned my interest in the geology of the region to the nice folks of the Chamber of Commerce, they suggested that I go to Obsidian Dome, where I would be able to collect some samples to share with my fellow Spaceward Bound! scientists. I thought that was a great idea, and headed off on another adventure. At the entrance to the Obsidian Dome road, I happened to meet up with a Ranger, and talked with him for a while. I wanted to make sure that it was ok to collect samples from this location. He said that it is ok, but only in small amounts, on the order of a gallon pail per person, which was fine by me. He also told me that the road to Obsidian Dome was still pretty soft (there was snow in several places), but told me where I could find a place with much more easily reachable volcanic rock samples. To make my long story short(er), I now have a bunch of samples of obsidian for some of my fellow scientists to take back to their classrooms after the expedition.

All-in-all, a perfect start to the week!

Thursday, March 22, 2007

Last Minute Preparations

Well, it's almost time! I'm leaving for the Mojave, bright and early tomorrow morning. Of course, in the true spirit of a road trip, I am making a few stops along the way. There's a clue as to the whereabouts of my second stop, if you look really closely at the roof of my truck. I'll be arriving in Zzyzx Sunday afternoon, hopefully with enough daylight to set up my camp. Of course, photos will be incoming! I'll probably create another .mac photo album, and post a link in the list to the right.

I don't know whether I'll be able to update daily from the road, and Zzyzyx, but I'll be keeping a paper journal in the field, and I'll make plenty of text entries on my computer for upload when I have a connection.

Yes, we students get the true "field expedition" experience, and get to stay in tents for the week. Personally, I'm looking forward to it. Given the choice between the 12-people-to-a-room dorms, and a one-person-in-my-HUUUUUGE-tent, I'll take the tent. We still get access to the showers, toilets and catered food, so it should be really fun!

I still haven't decided whether I want to go with the "try a little bit" of all the science themes, or go into one in depth. I was originally thinking that I wanted to sample all of them. But, if I sample all, I won't have the chance to see one project all the way through from beginning to end. Ah well, decisions, decisions.

Dr. Kress took Peng, Melissa and me to NASA for the teleconference, yesterday, where we got to meet a few of the people who are running the show. The main presenters were late, so we were treated to an off-the-cuff presentation by Dr. Kress about how our Astrobio class is going, what we're studying, and what we are planning on doing in the desert. We even got to make fools of ourselves on the live teleconference by trying to introduce ourselves. I wish I had known we were going to be on the telecast, because I would have worn my "blue screen" t-shirt, and been a disembodied head, floating next to Dr. Kress for my little intro. :D

One of my fellow adventurers, who I can't wait to meet, is Mrs. Chippy. It's not often you get to meet such a well-traveled celebrity. Maybe I can get a picture and an autograph with her.

Saturday, March 17, 2007

Desert Soil Biology

...or where our intrepid hero attempts to learn and explain graduate-level microbiology.

The first of four "Science Themes" we will be exploring while in the Mojave is an examination of the microbiology of the soil there. Obviously, we're expecting something vastly different from what you would find in your backyard. The Mojave is considered an extreme environment, with multiple conditions combining to make it nearly impossible for "normal" life. The Zzyzyx research station is located in the driest area of the Mojave, where they receive less than 2.5 inches of rain annually. Combining with the lack of water, high temperatures (100°F+), high radiation (that would be UV radiation, not nuclear), and in some areas, high salt or alkaline concentrations all mean that we will be searching for a class of bacteria know as extremophiles.

The extremophile most people know about is the bacteria living around the "Black Smoker" hydrothermal vents in the Pacific. These bacteria thrive in water that is up to 350°C (600°F+) and at pressures above 250 atmospheres. Conditions in the Mojave are mild in comparison! Well, except for the fact that there's no water.

The previous Spaceward Bound! expedition was to the Atacama Desert in Chile. Conditions there are even drier than in the Mojave, yet they were able to find and culture several bacteria colonies from air samples taken in the driest part.

I expect that we will find all sorts of lil' critters in the driest, hottest part of the Mojave. It's really just a question of what we will find and, more importantly, how they have adapted to live in these extreme conditions.

Dr. Kress' Astrobiology class is lucky to have one of the principal researchers for the extremophile portion of the expedition, as a regular attendee of our class. She, and one of the other researchers have given us a real crash course in what we can expect to find, how we're going to be detecting the critters, and what kind of things would be "cool" to find.

Our method will be to collect soil samples from various locations near our research base, and attempt to find the things growing within them. We'll probably start with the classic method of attempting to grow the sample in a petri dish. We should get a pretty good sample this way, since it worked even in the Atacama.

We will also have more technically advanced methods available. We'll be using "microplates" to determine which organic compounds are present in the soil. We'll even have a "DGGE" gene sequencer on site to do DNA analysis. Since bacteria are relatively simple organisms, their genomes are well known, and we can tell which bacteria are present in a sample by seeing which genes come up. We don't actually have to have a live bacteria to know it is present in a sample.

Personally, I'm hoping that we find some chemolithoautotrophs. :D

Yeah, yeah, I'm using a scary biology word! Breaking it down, it's just describing a type of bacteria that uses oxydation of chemical compounds as an energy source (chemo-), as opposed to light (photo-), reduced inorganic molecules (-litho-), instead of organics (-organo-), and CO2 as a carbon source (-autotroph) instead of other organic compounds (-heterotroph).

I'm not a biologist (but I will be playing one in a couple of weeks!), but I suspect that finding such a beastie would be nigh impossible in the Mojave. With such an abundance of sunlight, pretty much everything there would use the "easy" energy source.

Honestly, I'm going to have fun finding pretty much anything. If its unusual, I'll be ecstatic.

I'll also be curious to see if we take samples from below the surface. If we do, we'll potentially find some anaerobic and/or some non-light-dependant cultures.

The long term goal of our investigation of what we find in the Mojave is to increase the efficiency and accuracy of our planetary probes, and future manned expeditions. Using samples and data gathered in the Atacama, the previous expedition determined that if the Viking landers had touched down in a place like the Atacama, they would have failed to find the life there. Considering that Mars is even drier than the Atacama, its not all that surprising that the Viking landers came up empty. The question is: did they come up empty because there wasn't life to find, or that they were using flawed techniques?

Our expedition is providing a critical data point on the path to determine the "right" techniques.

Photo Deinococcus Radiodurans - A radiation tolerant extremophile. Photo Credit: Public Domain

Tuesday, March 13, 2007

Homework #3 - or how to dig a hole.

Yeah, yeah...I know, I haven't done homework #s 1 and 2 yet...Bad Mike!

Well, not really. I did introduce myself to my group leader Geoff Hammond, and got some tips for getting the most out of my expedition trip. I'll consider posting them here, if I get desparate for content. ;)

Anyway, our latest homework assignment is to re-write the soil sampling protocols from the GLOBE Gravimetric Soil Moisture Protocols. We are to "Re-write the protocols so that they enable you to do sterile sampling on Mars.".

It may seem like a scary assignment, but I suspect that it's more of a thought experiment. The GLOBE protocols, despite their complex-sounding name, are really meant for school-age kids as an experiment for a science class period or two. The "Gravimetric" descriptor really just means a weight-based measurement of the soil's moisture content. I suppose it's a fun way to get the kids to add a new word to their scientific vocabulary, and scare their parents. :D

There are three basic experiments. All involve weighing a "wet" soil sample, then cooking it to remove the moisture, and re-weighing it to determine the amount of water lost. Here's the actual protocol for the "Depth Profile Soil Moisture Protocol":
In the Field:
1. Complete the top portion of the Depth Profile Soil Moisture
Data Sheet.
2. Locate your sampling point on the star and cut and pull away
any grass or groundcover.
3. With the trowel, dig a hole 10-15 cm in diameter down to 5
cm. Leave this soil loose in the hole.
4. Remove from the loose soil any rocks larger than a pea (about
5 mm), large roots, worms, grubs, and other animals.
5. Use your trowel to fill your soil container with at least 100 g
of the loose soil.
6. Immediately seal the container to hold in the moisture.
7. Record the container number and mass on the Data Sheet next
to Sample Depth 0-5 cm.
8. Use the auger or trowel to remove all of the soil from the hole down to a depth of 8 cm.
9. In a clean container, collect a soil sample that contains the soil between 8 and 12 cm deep.
Remove rocks, large roots and animals. Seal the container.
10. Record the container number and mass on the Data Sheet next to Sample Depth 10 cm.
11. Continue to auger down to obtain samples centered at 30, 60, and 90 cm. Record the
container numbers and mass values on the Data Sheet.
12. You should have 5 containers of soil taken from 1 hole. Return the remaining soil to the hole
– last soil out, first in.

See? It's not all that difficult!

So...What would I suggest changing for performing the same sample on Mars?

Well, first there is the obvious:
1) If you're seeing grass or other groundcover, stop the experiment immediately! Carefully mark and note your location, and notify as many people as you can. You have just found very strong evidence of life on Mars, and your measurement of water in Martian regolith can wait! This notation would also apply in the case of finding the "large roots, worms, grubs and other animals" mentioned in steps 4 and 9.

2) Remember to take into effect that the force due to Martian gravity is different from that on Earth. This may be of particular importance when using a gravimetric protocol. ;)

Ok, now to be serious...

I'll limit my comments on the GLOBE sampling protocols when applied to the Martian environment to two issues. You wouldn't want me to eat all your bandwidth!

First, we are going to be interested in more than just the water content of a soil sample. Various other liquids or, more likely, volitile solids may exist in Martian soil. In addition, the surface temperature (and pressure...more on that later) of Mars, about 235K, would indicate that water would only appear in solid form. There is also the potential for solid CO2 (dry ice), as well as the possibility of frozen NH3, (ammonia - freezing point at about 200K), or possibly liquid or frozen simple hydrocarbons, or even more complex compounds, like amino acids. The process of heating the sample to "dry" it would also cause these other compounds to vaporize. Now, on Earth we have an extremely large amount of water in the soil, relative to other compounds. So much so, that we can ignore their contributions to the soil's moisture content, particularly with the error margins obtained in the GLOBE experiments.

On Mars, we don't know as much about which compounds will be present, nor do we have an exact expectation of their relative quantities. We expect CO2 and H2O to be the most prevalent, but we need to add an additional step to the measurement process to make our "Gravimetric" process work.

I would like to analyze the compounds that vaporize as a result of heating our sample, by using a mass spectrometer or similar insturment. Granted, we could also use the mass spectrometer to analyze the actual amount of water in our sample (it would certainly be easier!), but that would be "cheating" since it's not using the gravimetric measuring protocol!

Once we know what compounds are present, we can heat our other samples to a point where the compounds with lower vaporization points will evaporate out, but not hot enough to vaporize the water (again, there's the pressure problem...I'll talk about that in a minute). Once the other compounds have been removed, we can take our initial sample weight, and then heat our sample to a point where the water will vaporize out, but not so high as to vaporize compounds with higher vaporization points. We can then weigh our "dry" sample, and determine the water content using our gravimetric protocols.

Now for that little issue of pressure I mentioned earlier...

The atmospheric pressure near the surface of Mars is extremely low. Only about one percent that of Earth's. That means we will have to deal with sublimation of ice and other volitiles. For surface samples, its not too big of a deal anything that could vaporize/sublimate will have already done so. But for our deepest samples, at 90cm, we could lose a significant amount of our volatiles, simply by exposing the sample to the mars atmosphere.

There's a paper (Chevrier, V., D. W. G. Sears, J. D. Chittenden, L. A. Roe, R. Ulrich, K. Bryson, L. Billingsley, and J. Hanley (2007), Sublimation rate of ice under simulated Mars conditions and the effect of layers of mock regolith JSC Mars-1, Geophys. Res. Lett., 34, L02203, doi:10.1029/2006GL028401.) which discusses how ice buried under as little as one meter of regolith can last for as long as 800 years, when it would completely sublimate at the surface.

As long as our sample is exposed to the low atmospheric pressure, we will have skewed results.

My solution would be to either use a mechanical method to "seal" the sample as it is retrieved from the depth - something like an airtight core sampler, as opposed to a trowel, or to have some sort of pressure seal around our sample site, and pressurize the area, using an inert gas (He, Ne, Ar or maybe N2), so that sublimation effects wil be reduced.

Ok - homework assignment done. Just a final word of commentary. Even a "simple" experimental process on Earth is going to become vastly more complicated on Mars (or the Moon, or Titan, or Europa, or...). The best way to get these experiments to work is to get as many people thinking about them, ahead of time, as possible. Our expedition to the Mojave, the previous expedition to the Atacama Desert, and future expeditions expose a wide range of people to just some of the conditions our future explorers will face. Hopefully, we can all add our own small contributions to make things easier for them.

The photo above is of compacted Martian Soil. Credit: NASA's Mars Spirit Rover Team

Monday, March 5, 2007

I spent most of yesterday catching up on all the reading I need to do for both the Mojave trip, and my Astrobiology class. From what I can tell, the scientific background required for the Spaceward Bound! expedition is a bit less than what we are doing in our upper-division Astrobio class, but it's still new science to me anyway....Particularly the (micro-) biology.

The way Dr. Kress is running our Astrobio class differs from your "average" college class. We have a very wide selection of students from both the Biology and Physics fields (I think I technically fall into the Physics side of things, but its all still "new" to me), both graduates and undergraduates. A large portion of the class is taught by our fellow students, who are responsible for teaching a lecture or two within our field of expertise, and one completely outside. So far, we have had some "basic" physics, molecular chemistry and thermodynamics, as well as some more advanced topics in micro-biology and evolution. Today, Dr. Kress started us into the geologic side of things with an intro-level discussion of the evolutionary history behind our planet, specifically the temperature over time as a function of solar radiation and greenhouse effects. Pretty straightforward concepts, with much debate on the "what actually happened" side of things.

The other readings I am catching up on are:
Desert Landforms and Surface Processes in the Mojave National Preserve and Vicinity
The camels of the prokaryotic world
Endolithic Cyanobacteria in Halite Rocks from the Hyperarid Core of the Atacama Desert
Assorted readigns on micro-bacterial soil crusts
A genomic timescale of prokaryote evolution: insights into the origin of methanogenesis, phototrophy and the colonization of land
Evidence for Life on Earth Before 3800 Million Years Ago
Oxygen-isotope evidence from ancient zircons for liquid water at Earth's surface 4,300 Myr ago
Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago
Exotic Earths: Forming Habitable Worlds with Giant Planet Migration
Lecture Notes on the Formation and Early Evolution of Planetary Systems

My motive in putting all these links here is mostly so I can have one central location for my own reference. This way I don't have to go wading through all the e-mail and html links people sent me in order to find that one article with the interesting info. I'll just come here and see what's on my list.

The last two articles on planetary formation are source material for my own presentation for my Astrobio class. I'll be presenting some basic theories on terrestrial planet formation, particularly as it applies to our solar system and in the formation of conditions favorable to life.

If you're interested, and will happen to be in the SJ area on April 6th or 9th, drop me a line, and I'll see what the class thinks about having guests for my lecture. Remember, no promises on the accuracy or completeness of my topics. After all, I'm just a lowly undergrad student!

Saturday, March 3, 2007

Mike's Bio

We have to submit a "Bio" blurb for NASA to post on the Spaceward Bound! Info page. Here's mine:

I was originally educated as a Mechanical Engineer, but never really got going in the industry due to the defense industry downturn of the late 80s. Like any unemployed, recent graduate, I moved back in with my parents, and began graduate studies. Before finishing my Computer Science Masters, I lucked out and received an offer from one of Silicon Valley's "dream" companies -- at least for a computer geek.

I remained with the same company for twelve years, until I decided to retire last year. I have no intention of remaining idle, though. I am back in school now, pursuing studies in (Astro-) Physics, Applied Mathematics and Economics at San Jose State University (SJSU).

I am currently in training for my Shotokan Karate Shodan (Black Belt) with my other interests varying widely from skiing, ice hockey, SCUBA and mountain biking to the more intellectual pursuits of amateur astronomy...and yes...the orchids in the picture are mine.

A little more on the pictures:

The underwater picture was taken in about 60' of water at a place called Blue Corner in Palau (Micronesia). If you click on my Palau photo album, you can see some more pictures from that trip. I'm giving the big "thumbs up" signal, because an eagle ray had just spent about 5 minutes hanging within arm's reach from me in the current over the edge of the reef. It was awesome.

The orchids have a bit of a story. They are inherited through a couple of generations. I believe that they were originally my Aunt Vyolet's, who gave them to my mother. When my parents moved to Hawai'i from Lafayette, they couldn't take the orchids with them, so I inherited them. They are really hardy, at least in my back yard, and produce some beautiful blossoms once or twice a year.

Friday, March 2, 2007

I'm In!

Well, I just got the "official" word from both my Astrobiology professor, Dr. Kress and the co-director of the program, Dr. Coe that they managed to get me, and three others in my class, into NASA's Spaceward Bound! Expedition: Mojave 2007 program. Two others from our Astrobio class will also be at the facility during the same time, although they will be doing research for a separate class.

We'll be heading down to the Zzyzx research facility for five days, over SJSU's Spring Break, and participating in a number of different research projects. The idea behind the program is to infect teachers with an enthusiasm for space and exploratory science, which they will be able to pass on to their students. These same students being the ones who NASA will be sending to the Moon and Mars.

While all four of my class' participants are either in the science teaching track, or have an interest in teaching, we do have a bit of an ulterior motive for making the trip. We're actually studying the same science as part of our coursework. Since it's such a new and diverse field, it's one of the few classes we can take as either upper-division undergrads or grad students which will put us right at the cutting-edge of the science. Most other fields, especially in Physics, require years of study to get to the forefront of the field.

Of course, since we were added late, we are already behind in some of the coursework. No big deal. We're students. We can cram! :D

We have a bunch of essays to write. Nothing really difficult, just doing a bit of research on the web to help us determine which of the four "Science Themes" we will be interested in, and want to concentrate on for our week there. Being the Renaissance man kinda guy I am, I'll probably go for the "Sampler Plate", to get a taste of all four themes.

Another part of my "homework" is what you are reading now...We're keeping journals of our thoughts and experiences during the program, as well as a record of our research and ... homework.

Our final "assignment" is to create a bio blurb, and answer the same essay questions which our teacher counterparts did during their application process. So, as soon as I find a good picture of myself (not many exist -- especially of the non-fat version of myself), I'll post my first homework assignment here.

(Photo Credit: