Evidence of acidic fog discovered on Mars

Soshanna Cole, anassistantprofessor at Ithaca College,appears to have discovered evidence of acidic fog altering thesurface of Mars. The discovery was made via an analysis of datacollected by NASA's Spirit rover over the course of its explorationof the Red Planet.

Spirit landed on Marsin January 2004, and, prior to becoming embedded in soft soil, made numerous breakthroughs that revolutionized ourunderstanding of Mars. Eventually, the rover stopped transmitting, with the lastcommunication with the robotic pioneer taking place on March 22, 2010.

As is so often the casewith NASA's flagship missions, Spirit is living up to its name, andcontinuing to provide insights into the Martian environment longafter falling into its perennial slumber.

Cole analyzed datacollected by Spirit from a dozen locations in theCumberland Ridge and the Husband Hill summit focusing on "watchtowerclass" rocky outcrops. It was discovered that the formationsexhibited notable abnormalities that hinted at a strangely Earth-likeprocess occurring on the Red Planet.

It is believed that achemical reaction between volcanically induced acidic water vapor,otherwise known as vog, and the watchtower class outcrops couldaccount for the abnormalities. The phenomenon is similar to instancesof vog occurring on Earth created by the Kilauea volcano in Hawaii.

When the vapor landedon the rocks, it is possible that it had the effect of oxidizing theiron present in the watchtowers, causing the mineral deposits tolose their shape, and take on a gel-like consistency.

Once the water from thevog evaporates, the gel essentially becomes a cementing agent,hardening to form unusual patterns on the rock surface. According toCole the process happened incrementally over prolonged periods oftime.

Variations in the levelof iron oxidization in the distinctive rocks could be the result ofdiffering exposure to the elements. For example, rocks that are moreexposed to sunlight, the gel evaporates faster, allowing for lessoxidization.

Source: The Geological Society of America