While it is more probable that the iron oxidations we see in these Serpentine Rapids on Barsoom are the result of geologic sulfur deposits interacting with wet iron beds… as we most often see here on Earth, there is at least a chance that the red-to-green speckles in these Martian rocks settled there, as a result of some two to three billion year old microbial (life-engendered) chemistry.

And that fires my imagination, as many here well know. Here’s the run-down from NASA — near Neretva Vallis river channel, in Jezero Crater:

…At Serpentine Rapids, Perseverance used its abrading bit to create an abrasion patch in a red rock outcrop named “Wallace Butte.” The 5-cm diameter abrasion patch revealed a striking array of white, black, and green colors within the rock. One of the biggest surprises for the rover team was the presence of the drab-green-colored spots within the abrasion patch, which are composed of dark-toned cores with fuzzy, light green rims.

On Earth, red rocks — sometimes called “red beds” — generally get their color from oxidized iron (Fe³⁺), which is the same form of iron that makes our blood red, or the rusty red color of metal left outside. Green spots like those observed in the Wallace Butte abrasion are common in ancient “red beds” on Earth and form when liquid water percolates through the sediment before it hardens to rock, kicking off a chemical reaction that transforms oxidized iron to its reduced (Fe²⁺) form, resulting in a greenish hue. On Earth, microbes are sometimes involved in this iron reduction reaction.

However, green spots can also result from decaying organic matter that creates localized reducing conditions. Interactions between sulfur and iron can also create iron-reducing conditions without the involvement of microbial life….

Now you know. Some 40 million miles, out into our cool night skies — there may once have been… some simple microbial life, even as our planet was just then giving rise to cooling water ponds from which (some two billion years later), the species that became… Lucy arose here, at Olduvai Gorge. Smile.

नमस्ते