NASA’s Mars Perseverance rover has provided a nighttime image of the Malgosa Crest abrasion patch located at “Serpentine Rapids.” This image was captured using the SHERLOC WATSON camera on the rover’s robotic arm. The abrasion patch, measuring 5 centimetres in diameter, features a notable green spot, approximately 2 millimetres wide. The image was taken on August 19, 2024, during the 1,243rd Martian day of the Mars 2020 mission.

Continuing the Journey of Discovery

Following its sampling of the “leopard spots” at “Bright Angel,” Perseverance continued its exploration of this fascinating region. Approximately 20 sols later, after navigating south from Bright Angel across Neretva Vallis, the rover encountered striking red rocks at Serpentine Rapids. Then there it created an abrasion patch in a red rock formation known as “Wallace Butte.” This patch revealed an array of colours, including white, black and green hues.

Understanding the Geological Significance

The discovery of green spots surprised the rover team. These spots, consisting of dark cores surrounded by fuzzy, light green rims, present a unique geological feature. On Earth, red rocks typically derive their hue from oxidized iron, similar to the colour of blood or rust. The formation of green spots, like those found at Wallace Butte, is common in ancient “red beds” on our planet. This process occurs when liquid water seeps through sediment, triggering a chemical reaction that alters the iron’s oxidation state, resulting in a greenish tint.

Exploring Possible Origins of Green Spots

While such changes can involve microbial activity on Earth, they can also arise from decaying organic matter or interactions between sulfur and iron. Unfortunately, the rover was unable to analyse the green spots directly due to space constraints. As a result, their precise composition code