A scientific team led by Yang Liu, a researcher at NASA's Jet Propulsion Laboratory, revealed important new details about a rare Martian meteorite named "Teghaza 001", which was found in the Sahara Desert in the country of Mali in 2022. Modern analyses showed that this meteorite formed more than 4.1 billion years ago, making it one of the oldest known Martian meteorites to date.
Most previously known Martian meteorites, such as shergottites and nakhlites, are relatively young, not exceeding 2.4 billion years in age. Before this discovery, only two truly ancient meteorites were known: "Allan Hills 84001" and another rock piece known as "Black Beauty". "Teghaza 001" is a hard, coherent igneous rock that represents a qualitative and distinct addition to the sample collections available to scientists on Earth.
What did the analyses reveal about the history of Mars?
The scientific team used several independent methods to date the rock, including the analysis of zircon grains and phosphate minerals, which yielded identical results indicating an age of about 4.11 billion years. The examinations also showed the presence of sodium-rich rims and hot water that interacted with the rocks inside, confirming the existence of active water circulation and a hydrosphere on early Mars, and its intense interaction with the Martian crust at a very early time.
In addition, the trace element ratios and the analysis of the magma source in the Martian mantle indicated that the Martian mantle was evolving in a more complex and different way than previously thought during the first hundreds of years of the planet's formation. Based on a comparison of chemical characteristics with orbital maps, researchers suggest that the meteorite may have originated from the southern highlands of Mars.
What does this mean for the scientific future?
This discovery represents an advanced step in understanding the early geological history of Mars and its potential habitable environments within its crust. However, studies emphasize that obtaining samples with a direct and precise geological context from ancient surfaces, such as those being collected by the Perseverance rover in Jezero Crater, remains the true key to revolutionizing our understanding of Mars and the early solar system.