Lithe Canyon Biological Observations

Context: EVA #15 to Lithe Canyon, making biological observations and looking for dinosaur bones and petrified wood.

Summary: An interesting journey, in sim, down into Lithe (Lith) Canyon. The almost vertical canyon walls had many caves and crevices, likely suitable for bats. The following plants and animals or animal signs were seen.

Animals Lizards (3) Foraging ants (5 anthills) Rabbit tracks Flies Small mammal burrow and tracks

Plants Saltbush Russian thistle (tumbleweed) Rabbitbush?

On Plateau desert buckwheat Eriogonum inflatum (several parasitized by moth larvae) Mormon tea (Ephedra sp.)

CO₂ Experiment:

Context: Biology lab work from EVA #6 (Biology EVA #2) to Tank Wash on March 4, 2004. See Biology Report from March 4 for details on field work and sampling location.

Summary of Lab Work: On March 4, the samples were prepared to test for microbial richness. Open vials of approximately 4 g of soda lime were placed in the sampling containers, which were then sealed for approximately 6 days. Instead of being placed in an incubator, the samples were set on the lab counter in the Hab. Today, the samples were opened, and the masses of the sample and soda lime were re-measured. The used soda lime was placed in an empty soda lime container, which was re-labeled "Used Soda Lime" and the samples were thrown outside. The soda lime vials were left out to dry and may be cleaned later, while the sampling containers were discarded.

CO₂ Experimentation Status: These samples were the second of four sets. The mass data were added to the Excel spreadsheet from previous lab work, which was submitted to RST. The remaining two sample sets will be revisited on March 11 and 12.

Summary of Data and Observations: For the most part, the re-measured soil sample masses are greater than the original masses. This change may be due to the addition of 2 mL of water to each sample, since the water was unable to evaporate through the sealed lid. Unlike the previous set of samples, these did not have condensation on the lids, most likely because these samples were much larger than those of the previous set. Most of the changes in soil sample mass were in the range 1.58 g to 1.92 g. However, samples 2 and 6 showed large deviations in mass change.

• The mass of sample 6 actually decreased by 5.39 g, which could be partially explained by the fact that some soil had gotten mixed in with the soda lime and was discarded. This amount of soil was small, though, so this is probably not the full explanation. More likely, a simple measurement error occurred. However, the data from this sample should not be discarded, because it may fit with data from other sample sets, depending on physical factors associated with the collection site.
  
  
• The mass of sample 2 increased by 8.67 g. No explanation for this large change is forthcoming, except possible measurement errors. Again, the data from this sample should not be discarded, because they may be legitimate if they fit with data from other sample sets. The final masses of soda lime for this sample set are consistently greater than the initial masses. The change in soda lime mass ranges from 0.19 g to 0.49 g. Besides these two extremes, the rest of the data are within a much smaller range, 0.30 g to 0.38 g. These results fit the expectations, because the soda lime should absorb water and CO2, thus increasing in mass. When these data are compiled with data from previous sets, some more explicit trends based on sample type and physical surroundings should emerge.

Conclusions: This data set seems much more useful than the first set, for a few reasons. Most of the samples were close to the minimum recommended size, and several were over. Also, these data actually showed some correlation, unlike the last set. When they are added to the previous data sets, they should provide some useful information. Today's experimentation also provided a useful lesson. Be careful transporting the sampling containers! If they are jostled too much, soil will get mixed in with the soda lime and soda lime will get mixed in with the soil. Besides possibly influencing the results of the experiment, this mixing makes cleanup more difficult because the soda lime and soil should be separated.