A meteorite that fell to Earth from Mars is giving planetary scientists something they have never had before: a rock from a middle chapter of the Red Planet's volcanic history. Researchers at Boston College have dated the meteorite — known as Northwest Africa (NWA) 13441, an 84.69-gram specimen recovered in Algeria in 2019 — to approximately 1.273 billion years old.

That age is remarkable because of what it is not. The most common Martian meteorites, the shergottites, mostly record other eras of Mars' history, clustering at certain ages and leaving a vast middle period essentially unrepresented. "No other Martian meteorite like this is 1.27 billion years old," the team said. The new dating fills a gap of roughly two billion years in the shergottite record.

Even more striking is the rock's chemical fingerprint. Its neodymium isotopic composition matches the initial solar system — a primitive, chondrite-like signature unlike that of any other known shergottite. That suggests NWA 13441 was forged in a region of Mars' deep interior that has never been sampled before, a chemically pristine mantle reservoir that has apparently stayed isolated from the mixing that shaped other Martian magmas.

The find matters well beyond filling a timeline. Because shergottites are our only physical samples of Mars' volcanic crust, their age and composition gaps have skewed how scientists reconstruct the planet's internal evolution. A rock from a previously unsampled source shows that Mars' mantle produced a wider range of compositions than the meteorite collection on Earth had suggested, and it offers rare direct evidence about the deep interior — context that also sharpens the interpretation of data from Mars rovers and future sample-return missions.

The team reported its findings at the Goldschmidt geochemistry conference, with the full study published in a new peer-reviewed paper on the petrogenesis and mantle-reservoir implications of NWA 13441.

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