A distinctive rose-colored meteorite discovered in the Sahara Desert in 2022 has been identified as one of the oldest known pieces of Mars, according to new NASA-funded research. Named Teghaza 001 after the salt flat in Mali where it was found, this nearly 2-pound (800-gram) space rock formed over 4.1 billion years ago, making it one of only three extremely ancient Martian meteorites discovered on Earth. Scientists used advanced techniques to analyze the specimen, uncovering crucial insights into the Red Planet’s early geological development.
Published in the journal Science, the study provides an unprecedented look at Mars’ primordial crust. The research team, led by Yang Liu of NASA’s Jet Propulsion Laboratory, determined that Teghaza 001 contains a unique mixture of volcanic minerals that reveal how the planet’s crust formed from cooling magma and was later modified by subsurface water activity. These findings align remarkably with observations made by NASA’s Mars Reconnaissance Orbiter in the planet’s ancient southern highlands.
“It was only after we started looking closely that we realized this meteorite is really unique,” said Liu, the study’s lead author. “One of the paper’s reviewers described it as a Rosetta Stone for Mars.”
What distinguishes Teghaza 001 from other Martian meteorites is its complex texture, exceptional age, and distinctive igneous minerals. Unlike ALH84001—another ancient Martian meteorite composed almost entirely of a single mineral—Teghaza 001 preserves diverse clues about early Martian processes. The youngest of the trio, nicknamed “Black Beauty,” formed approximately 2.1 billion years ago and consists of small volcanic rock fragments.
Analysis of zircon crystals within Teghaza 001 allowed researchers to precisely determine both its formation age and subsequent alteration history. Using an innovative in-situ rubidium-strontium dating method developed by Caltech’s Francois Tissot, the team analyzed mineral grains smaller than a fingernail, enabling precise age determination while preserving the rare specimen for future investigations.
“Right now, we are one of very few labs in the world able to perform this kind of age-dating, and the first to date such an ancient Martian meteorite,” said Tissot. “Our hope is to pave the way for dating even more Martian meteorites, or samples returned from other planets, their moons, and asteroids.”
The most significant discovery was evidence of water alteration occurring approximately 4.1 billion years ago, suggesting the meteorite originally formed even earlier. Isotopic analysis, mineral textures, and chemical compositions indicate a remarkably active water cycle existed on early Mars, challenging previous assumptions about the planet’s environmental evolution.
“This is really our first piece of Martian crust from a part of Mars we’ve never had a sample of before,” noted Lee Saper, the study’s co-author and current scientist at NASA’s Ames Research Center. “It records interactions of water and rock and maybe even an imprint of the Martian atmosphere as it was losing water.”
The research team verified Teghaza 001’s Martian origin by matching its oxygen isotopes—geochemical signatures that serve as planetary fingerprints—to data collected by NASA missions including the Viking landers and the Curiosity and Perseverance rovers.
Future studies are expected to yield additional revelations about early Mars. “We’ve only scratched the surface,” Liu remarked, emphasizing the scientific community’s anticipation for deeper analysis of this remarkable specimen.