A group of scientists from the University of Florida (USA) has identified the oldest Martian meteorite found to date, which would date back more than 1.7 billion years. The rock, barely six centimeters in diameter, would have wandered through space during this time until finally impacting our planet last year in the Sahara desert.
Igneous rock NWA 7533 is the first of five fragments attributed to the meteorite itself, fragmented upon entering the atmosphere. Geological analysis has revealed that it is a regolithic breccia, that is, a material formed by the compaction of different minerals over time. The presence of pyroxenes, characteristic of the basaltic rocks analyzed on the Martian surface, and of zircon, a mineral of great antiquity, reveal that it comes from the original crust of the planet, formed approximately 4,000 million years ago.
The number of Martian meteorites identified ranges between 60 and 100, although according to scientists, the number of rocky fragments that land on our planet is much higher. However, most of them are never discovered due to the difficulty of locating them in oceanic areas (which account for two thirds of the earth's surface) and the difficulty of acquiring them due to the sale of meteorites in desert areas.
The finding will provide valuable information on the process of formation of the Martian crust , and therefore, on the formation of the crust of the Earth and the Moon, since all of them originated in the same period.
