Curiosity discovered a surprising ‘metallic flower’ on Mars

a few days ago, Rover Curiosityis still active on Mars, took Photography Very strange: on sandy ground he hits her winds Mars stands small concrete flower shaped metal Barely 1 cm wide, it has several arms attached to the base.

However, this is not the first time Curiosity has depicted this type of formation. For scientists, it is the result of the process of generation, which means that it is the result of a rearrangement On site From metal, which leads to the growth of a new crystal. The formation of this type of structures is significantly associated with the presence of water saturated with sulfate.

The Martian analogue of our sand rose

In this sense, it could be the Martian analogue of our rose from sands. The appearance of the formation is already reminiscent of evaporative concrete. On Earth, evaporites sedimentary rocks Resulting from the sediment that is deposited during the evaporation process A liquid supersaturated with chlorides or sulfates (Brine). Rock salt is the best known vaporizer, but gypsum or anhydrites are also part of this class of minerals. So evaporators are generally formed in shallow basins, which are subject to strong evaporation and faulty hydrological system, such as lakes or Dead Sea.

Known sand roses are formed under specific conditions. These wonderful rocks the color Orange are crystals gypsum In a generally sandy environment. So sand roses do not form in the same way as gypsum in the middle. Lake. Gypsum crystals grow even within an incoherent medium (such as sand orclay), soaked in groundwater level rich in Calcium sulfate. As evaporation progresses, the groundwater table is concentrated in ions, until saturation allows crystallization of metals. Crystals grow by pushing sand around. Thus, we find sand in desertsBuried under a few meters of sand.

Small metal flower discovered by erosion

A similar process could be the origin of the so-called thin Martian concrete Blackthorn salt. Previous studies of similar concrete show that crystals would have grown within the soil. But how do we explain their presence on the surface today? Simply by corrosion process. Over time, the Martian winds scraped away the rocks, even highlighting these small stones. More resistant to corrosion due to its nature, this concrete is now found on the ground, like a small metal flower with Mars surface.

At another site on Mars studied by Curiosity, the composition of this type of concrete was analyzed using instruments ChemCam / LIBS and APXS. It appears, for this site at least, that concrete blocks are particularly rich in magnesium (Mg) and in several species of sulfide (S). The chemical structure will be mainly MgSO_4, What distinguishes these concretes from ground gypsum, from the formation of CaSO₄.

This type of concrete gives a lot of information about the past environment of Mars, especially about the presence of water in the form of brine in its vault.