A recent NASA-funded study has detailed the analysis of one of the oldest Martian meteorites ever discovered on Earth, a pinkish rock known as "Teghaza 001" weighing approximately 800 grams. This meteorite was found in the Sahara Desert, specifically in the salt flats of Mali in 2022, and analyses show that it formed more than 4.1 billion years ago, making it one of the oldest Martian meteorites discovered to date.
The initial results were published in the journal Science, and the researchers provided a rare glimpse into the ancient crust of Mars and its composition. What distinguishes this meteorite from other Martian meteorites is its unique igneous texture and minerals, which tell the story of how the planet's crust formed from cooling magma before being affected by groundwater. The mineral composition of the meteorite matches what was observed by NASA's Mars Reconnaissance Orbiter in the southern highlands of Mars.
What changes in practice?
The researchers, led by Yang Liu of NASA's Jet Propulsion Laboratory in Southern California and with the participation of François Tissot of the California Institute of Technology (Caltech), used a modern dating technique based on in-situ rubidium and strontium. This innovative method allowed for the analysis of individual mineral grains on the surface of a sample smaller than a fingernail, rather than traditional techniques that require dissolving the entire sample. This technique provides high accuracy and speed while preserving rare samples for future studies, and opens the door to dating more Martian meteorites or samples coming from other planets, moons, and asteroids.
What does this mean for the future?
Evidence derived from oxygen isotopes and the chemical composition of zircon crystals discovered within "Teghaza 001" points to a highly active water cycle on early Mars, and documents the interaction of rocks with water and possibly the melting of the Martian atmosphere as it lost its water. The researchers identified 13 potential locations on the surface of Mars that match the meteorite's minerals and chemistry, giving scientists the first real piece of Martian crust for which no samples were previously available.