Development of elemental biosignatures

Developing an elemental biosignature for silicified microbial fossils

Impending missions focusing on the search for life outside of our planet require the development of robust and conclusive biosignatures. Some of the oldest evidence for life on Earth comes from hydrothermal silica deposits, which also are thought to exist on the surface of Mars. Imaging data of matrix and trace elements were obtained with the IMS 7f-GEO from modern and recently silicified organisms preserved in terrestrial hydrothermal silica-depositing environments. Results show that several elements such as C, N, P, S, Cr, Mn, Fe, and Ga are often co-localized in or around preserved organics, indicating that these elemental distributions could have an application as a biosignature. 

Recorded on CAMECA IMS 7f-GEO at WUSTL, Missouri, USA. Image courtesy of A. Gangidine and C. Jones.
A. Gangidine et al. Trace element concentrations in hydrothermal silica deposits as a potential biosignature. Astrobiology, 20(03). (DOI: 10.1089/ast.2018.1994.) (2020)

Winning image for the month of August 2020