Patrick Gasda, from the Space Sciences and Applications group at Los Alamos National Laboratory and main author of the study that highlights the discovery of manganese – chemical element, symbol Mn, atomic number 25 and atomic mass 55 u, solid at room temperature – on Mars, states that it is very difficult for the oxide of this chemical element to form on the surface of Mars and that’s why the team I did not expect to find it in such high concentrations in a coastal deposit.
Patrick Gasda.
As for Mars, we have no proof that life exists or ever existed and the mechanism of oxygen production in the ancient atmosphere of Mars is also unclear, so how the manganese oxide formed and concentrated in that location is really intriguing. These findings point to larger processes occurring in the Martian atmosphere or surface water and show that more work is needed to understand oxidation on the Red Planet.
The discovery process
Developed by Los Alamos and CNES (French space agency), the ChemCam employs a laser to vaporize rock surfaces and analyze the plasma resultant in terms of its elemental composition.
The team studied a variety of sediments in the crater, including sands, sediments and muds. They noted that sandy sediments, being more porous, allowed groundwater to move through them more easily than the finer muds that dominate lake beds.
They explored how manganese enrichment could occur in these sands, possibly through the movement of groundwater near a lake or delta, and which oxidants could be involved in manganese precipitation in these rocks.
On Earth, manganese is often concentrated by oxygen in the atmosphere, a process often accelerated by microbial activity. Microbes use the various oxidation states of manganese to obtain energy. If Mars ever supported life, the high manganese content in these lakeshore rocks could have been a crucial energy source.
The environment of Lake Gale, as revealed by these ancient rocks, gives us a window into a habitable environment that is surprisingly similar to places on Earth today.
News reference:
Gasda P., Lanza N., Meslin P., et al. Manganese-Rich Sandstones as an Indicator of Ancient Oxic Lake Water Conditions in Gale Crater, Mars. JGR Planets (2024).
Tags: Discovery manganese Mars team researchers suggests ancient Earthlike conditions
