The wet chemistry laboratory on NASA's Phoenix Mars Lander has four
teacup-size beakers. This photograph shows one of them. The laboratory is
part of the spacecraft's Microscopy, Electrochemistry and Conductivity
Analyzer.
Each beaker will be used only once, for assessing soluble chemicals in a
sample of Martian soil by mixing water with the sample to a soupy
consistency and keeping it warm enough to remain liquid during the
analysis.
On the inner surface of the beaker are 26 sensors, mostly electrodes
behind selectively permeable membranes or gels. Some sensors will give
information about the acidity or alkalinity of the soil sample. Others
will gauge concentrations of such ions as chlorides, bromides, magnesium,
calcium and potassium. Comparisons of the concentrations of water-soluble
ions in soil samples from different depths below the surface of the
landing site may provide clues to the history of the water in the soil.
