Boston College Dates Mars Meteorite NWA 13441 to 1.27 Billion Years

Boston College researchers have determined that a Martian meteorite designated Northwest Africa 13441 (NWA 13441) crystallized approximately 1.273 billion years ago, filling a roughly 1.8-billion-year gap in the geologic record of Mars’ most common meteorite type. The team, led by Professor Ethan Baxter, published the findings in Geochimica et Cosmochimica Acta, reporting an isotopic signature never before observed in this class of rock.

A Meteorite From an Unsampled Region of Mars

Rocks reach Earth from Mars only when knocked loose by an impact large enough to escape the planet’s gravity, which has limited scientists to roughly 400 known Martian meteorites. NWA 13441, discovered in Algeria in 2019, belongs to the shergottite class — the most common group of igneous Martian rocks recovered on Earth.

Previously dated shergottites cluster into two groups: samples younger than 600 million years old, and a smaller set dating back 2.4 billion years. Between those two windows lies an approximately 1.8-billion-year span with no shergottite samples to inform scientists’ understanding of Mars’ magmatic and volcanic history. Two other rare meteorite classes, chassignites and nahklites, have been dated to 1.3–1.4 billion years, but their chemistry differs substantially from shergottites like NWA 13441.

What the Isotope Data Revealed

Baxter’s team, working at the Boston College Center for Isotope Geochemistry, focused on neodymium, a rare element with seven naturally occurring isotopes that serves as a geochemical clock. The neodymium isotopic composition of NWA 13441 matched the value expected for the initial Solar System — a signature the researchers say has never been observed in any other shergottite.

That “chondritic” composition, shared with chondrites, the unmelted rock aggregates that formed 4.56 billion years ago, suggests a portion of Mars’ deep interior has remained chemically unaltered since the planet formed. “The characteristics of this meteorite were entirely surprising,” Baxter said. “No other martian meteorite like this has an age of 1.27 billion years old.”

How the Sample Was Dated

Baxter’s laboratory obtained a small crushed sample and a thin section of NWA 13441 from a colleague at Appalachian State University; the rock itself had not previously been characterized in the scientific literature. Working with collaborators at the Scripps Institution of Oceanography and the UK’s Open University, the team applied high-precision radiogenic isotope techniques to confirm the rock’s Martian origin, establish its crystallization age, and characterize its chemistry against other known shergottites.

“Martian meteorites of this type are either younger than 600 million years old, or approximately 2.4 billion years old,” said Dylan M. Seal, a Boston College doctoral candidate and study co-author. “We dated this sample to be 1.273 billion years old, which fills a roughly 2 billion year gap for which we had no shergottite samples to provide information about magmatic and volcanic activity on Mars.” Co-authors Melody Z. Chen, a Boston College undergraduate researcher, and Robert W. Nicklas, a former postdoctoral scholar now at the Lunar and Planetary Institute, also contributed to the analysis.

Why the Chondritic Signature Matters

Mars formed within roughly 5 million years of the Solar System’s birth, according to Seal, and unlike Earth, it never developed plate tectonics. Without that mixing process, portions of the planet’s early mantle composition could persist largely undisturbed for billions of years. NWA 13441’s neodymium signature offers physical evidence that such a pristine reservoir survived into the geologically recent past, providing new constraints on the processes that shaped Mars during the Solar System’s earliest years and on how deep planetary interiors evolve once large-scale tectonic recycling is absent.

What Comes Next

Baxter’s lab is continuing to study the sample alongside undergraduate researchers and external collaborators. “Our goal is to analyze additional isotope systems that will help us better understand how this unique sample relates to other martian meteorites on early Mars,” Baxter said.

The 1.27-billion-year age places NWA 13441 as the first characterized shergottite from within the previously empty 1.8-billion-year window, giving planetary scientists a new fixed point for reconstructing how volcanic and magmatic activity on Mars evolved between the planet’s ancient and geologically recent past.

Source: Boston College — Department of Earth and Environmental Sciences, Center for Isotope Geochemistry. Published in Geochimica et Cosmochimica Acta (DOI: 10.1016/j.gca.2026.06.035). Primary source: eurekalert.org/news-releases/1139166.