NASA's Perseverance rover uncovers mysterious green spot on Mars
The Nasa rover Perserverance has recorded a mysterious green spot on Mars. Similar spots on Earth are caused by water.
Clearly visible at the top left: the dark green spots with light green edges puzzle researchers.
(Image: NASA/JPL-Caltech)
A new discovery on Mars is puzzling: With the help of the Sherloc Watson camera on board the Perserverance rover of the US space agency NASA, images were taken of a green spot located on red Martian rock. It is still unclear how the spot was formed. On Earth, however, similar spots are often caused by water
A few days ago, NASA published the images taken in August at the "Serpentine Raids" rock formation. According to NASA, the green spots were revealed during the removal of a rock surface using the Perserverance abrasion drill. The rover team was surprised by the dark green patches with light green edges, which are also clearly visible in the images.
On Earth, water is often behind them
The space agency draws a direct comparison with red rocks on Earth, which get their color from oxidized iron – the same form of iron that turns human blood red. Green stains also occur in red earth rocks when liquid water seeps through the sediment before it hardens into rock, triggering a chemical reaction that converts oxidized iron into its reduced form. This in turn leads to a greenish coloration.
On Earth, microbes are sometimes involved in this iron reduction reaction. However, green stains can also be caused by the decomposition of organic substances that create local reducing conditions. Interactions between sulphur and iron can also create iron-reducing conditions without the involvement of microbes.
Stains remain a mystery
The composition of the green patches on Mars will unfortunately remain a mystery for the time being. More detailed investigations were not possible due to a lack of space, writes NASA. Otherwise, the team would probably have decided to place the rover arm with the SHERLOC and PIXL instruments directly on one of the green spots within the abrasion.
The team hopes to make a similar discovery soon, which may provide an explanation. Next, the rover team sets course for the rim of Jezero Crater.
(nen)