Four years after its recovery in the Sahara Desert of Mali, the meteorite designated Teghaza 001 has been confirmed as a piece of Mars’ primordial crust that formed at least 4.1 billion years ago. The finding, published in the journal Science on Oct. 29, 2026, marks the oldest known Martian igneous rock and provides a rare window into the planet’s earliest geological history.
Discovery and Physical Characteristics
Teghaza 001 comprises eight fragments whose combined mass is 798.5 grams; the largest piece weighs 442 grams and measures roughly 10 cm across. The meteorite was located in the Sahara Desert of Mali and later examined by a team led by Dr. Yang Liu of NASA’s Jet Propulsion Laboratory. Liu noted that a detailed inspection revealed the meteorite’s unique nature, and a peer reviewer later described it as a “Rosetta Stone for Mars.”
Unlike the majority of the roughly 300 identified Martian meteorites, which are considerably younger than the planet’s surface, Teghaza 001 belongs to a distinct class. Most Martian meteorites fall into three groups—shergottites, nakhlites and chassignites—that crystallized 2.4 billion years ago or later. Only two older specimens had been recognized before this study: Allan Hills 84001, dated to about 4.1 billion years, and portions of Northwest Africa 7034, some of which exceed 4.3 billion years.
Age Determination and Geological Significance
Laboratory analyses identified Teghaza 001 as a coarse‑grained, plagioclase‑rich gabbro, an igneous rock that cooled slowly, likely beneath the Martian surface. Zircon crystals extracted from the specimen were dated using uranium–lead techniques, yielding an age of approximately 4.11 billion years. A complementary rubidium–strontium analysis produced a less precise but consistent estimate of around 4.24 billion years.
Researchers caution that these dates may reflect a period of hot, mineral‑laden water moving through the rock after it solidified, rather than the exact moment of crystallization. In either scenario, the rock must have formed no later than about 4.1 billion years ago, placing it in the earliest known geological epoch on Mars.
Implications for Martian History
Dr. Carl Agee, director and curator at the University of New Mexico’s Institute of Meteoritics, emphasized the meteorite’s singularity, noting that while the “Black Beauty” meteorite contains several components of similar age, Teghaza 001 represents a single, unaltered rock type dating to the same ancient period. He highlighted the meteorite’s evidence of water interaction: its oxygen isotopes are enriched in ^18O relative to other Martian meteorites, a signature the authors attribute to contact with ^18O‑rich fluids either within the crust or directly with the magma.
Additional mineralogical alterations observed in the sample indicate chemical changes on Mars prior to the impact that launched the rock into space. By comparing the meteorite’s chemistry with orbital observations, the authors propose the southern highlands—specifically an area northwest of the Hellas impact basin—as the most plausible source region.
Both Liu and Agee stress the rarity of such a sample. Agee remarked that the chance of acquiring another meteorite of this type in the near future is “very slim or next to impossible.” The discovery therefore adds a crucial data point for reconstructing Mars’ early crustal composition, mantle processes, and the role of water during the planet’s formative years.
Steve Lopez is a Senior Editorial Columnist and Health & Public Policy reporter for News Raise. Steve focuses on healthcare advancements, medical technologies, and public health policies.
