Context: Biology lab work from EVA #8 (Biology EVA #3) to Fathi's Creek on March 5, 2004. See Biology Report from March 5 for details on field work and sampling location.

Summary of Lab Work: On March 5, 20 samples from Fathi's Creek 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 third of four sets. The mass data were added to the Excel spreadsheet from previous lab work, which was submitted to RST. The remaining sample set will be revisited on March 12.

Summary of Data and Observations:

• For all the samples in this set, 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. The mass changes range from 0.84 to 1.95 g.
• 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 0.09 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 is even more consistent than the second set. All of the samples exceeded the minimum recommended size, so the results of the experiment should at least be noticeable. In this case, unlike in the second set, all of the changes in sample mass are positive and fall within a small range. All of the changes in soda lime mass are also positive and within a reasonable range. In this sample set, many of the samples had plant roots in the soil, which may or may not affect the results. Only comparing these data with previous data sets will tell.