Robots like Viking, Phoenix, and Curiosity have found indirect evidence of oxalate minerals on Mars. New techniques tested in the Chile’s Atacama Desert could help future Mars rovers analyze these minerals for possible by-products of life.
Organic oxalates tie up carbon, creating carbon sinks that are extremely resistant to most physical and chemical weathering. On Earth, oxalates are primarily broken down by biological weathering; fungus and bacteria consume oxalate, recycling carbon back into the environment. But Mars’s carbon cycle is not as well understood. Developing better techniques to identify trace concentrations of oxalates may provide insights into the processes at play on the Red Planet.
In a new paper [in the Journal of Geophysical Research — Biogeosciences], Cheng et al. used samples from a terrestrial analogue of Mars—the Salar Grande basin in the Atacama Desert—to test out various techniques for detecting and characterizing oxalate-bearing rocks. [More at links]