Mali Meteorite Dates to at Least 4.1 Billion Years Ago

A Martian meteorite recovered in Mali has been dated to at least 4.1 billion years ago, making Teghaza 001 one of the oldest such samples found on Earth and offering a rare record of the planet’s early crust. The study, published in Science, places the rock’s formation before water altered some of its minerals around 4.1 billion years ago. Researchers used rubidium-strontium analysis on feldspar and uranium-lead dating on zircon crystals, obtaining matching ages. NASA’s Jet Propulsion Laboratory said the analysis used a fragment smaller than a fingernail. The nearly 800-gram meteorite was recovered in the Sahara in 2022 and named for a salt plain in Mali. The study ranks it among the three most ancient Martian meteorites found on Earth. Its mix of igneous minerals, formed as magma cooled, gives researchers a sample of ancient Martian crust and clues to how the planet’s interior and surface evolved. A separate study in Science Advances examined hydrogen and deuterium in calcium phosphate minerals from the meteorite. The researchers reported evidence that water associated with Martian magma mixed with material bearing a chemical signature linked to an ancient hydrosphere. The...