Perseverance finds red rocks with green spots on Mars

Oct. 28 () –

NASA’s Perseverance rover on Mars has discovered an enigmatic and unique outcrop of red rocks with green spots during its climb towards the edge of Jezero crater.

A 5cm diameter abrasion patch made by the rover revealed a surprising array of white, black and green colors within the rock. One of the biggest surprises for the rover team was the presence of dull green spots within the abrasion patchwhich are composed of dark-toned nuclei with diffuse light green edges, NASA reports.

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 the metal that is left out. Green spots like those observed in the Wallace Butte abrasion – as the area has been called – are common in ancient “red beds” on Earth and are formed when liquid water seeps through sediment before it hardens into rock, triggering a chemical reaction that transforms oxidized iron into its reduced form (Fe2+), which results in a greenish tone.

On Earth, microbes sometimes participate in this iron reduction reaction. However, green spots can also result from the decomposition of organic matter creating localized reducing conditions. Interactions between sulfur and iron They can also create iron-reducing conditions without the involvement of microbial life.

Unfortunately, there was not enough room to safely place the rover’s arm containing the SHERLOC and PIXL instruments directly over one of the green spots within the abrasion patch, so its composition remains a mystery.

Science and engineering teams now face incredibly steep terrain as Perseverance climbs the rim of Jezero Crater.