“One of the paper’s reviewers called it a Rosetta Stone for Mars,” said Dr. Yang Liu of NASA’s Jet Propulsion Laboratory. NASA stated the find provides “a rare snapshot” of the planet’s crust and formation.
Teghaza 001 samples the earliest Martian crust
The meteorite consists of eight fragments totaling 798.5 grams. The largest piece weighs 442 grams and measures roughly 10 centimeters across. Unlike most of the 300 to 435 known Martian meteorites, which formed 2.4 billion years ago or later, Teghaza 001 is a coarse-grained igneous rock—specifically a plagioclase-rich gabbro—that cooled slowly underground.
Researchers used uranium-lead methods to date zircon crystals in the rock, arriving at an age of approximately 4.11 billion years. A separate rubidium-strontium analysis provided a date of about 4.24 billion years, though researchers noted this may reflect when mineral-laden water circulated through the rock rather than the moment of solidification. Either date places the rock’s formation in the earliest geological period of Mars. In summer 2025, Alicia Cruz-Uribe and colleagues measured isotopes at the California Institute of Technology showing the rock is 4.1 billion years old.
Did you know? The meteorite was named after the salt plain in Mali where Sahrawi prospectors discovered it in 2022.
Ancient Martian rocks compared
Teghaza 001 is one of only three Martian meteorites on Earth older than 4 billion years. While other ancient samples exist, they differ significantly in composition.
| Meteorite | Approximate Age | Composition/Nature |
|---|---|---|
| Teghaza 001 | 4.1+ Billion Years | Unadulterated igneous rock (gabbro) |
| Allan Hills 84001 | 4.1 Billion Years | Composed almost entirely of one mineral |
| NWA 7034 (Black Beauty) | 4.3+ Billion Years (fragments) | Conglomeration of many rock types |
Dr. Carl Agee, director and curator at the University of New Mexico’s Institute of Meteoritics, noted that Teghaza 001 is “just one unadulterated rock type,” making it the oldest Martian igneous rock found to date by a significant margin. Other ancient samples include “Black Beauty,” which formed about 2.1 billion years ago, and ALH84001, which is of a similar age to Teghaza 001.
Evidence of a dynamic water cycle
The rock contains chemical clues that it existed in an environment where fluids and water coursed through it. Its oxygen isotopes are heavier than those of other Martian meteorites, which researchers attribute to interactions with oxygen-18 enriched fluids in the crust or magma.
A separate study published in Science Advances in June examined the rock’s water content. Lee Saper, a scientist at NASA’s Ames Research Center, stated the meteorite may record the “imprint of the Martian atmosphere as it was losing water.” This suggests early Mars had a more dynamic water cycle than previously believed. Yang Liu, the lead author and a JPL researcher, said “it was only after we started looking closely that we realized this meteorite is really unique.”
Laser beams date rare meteorite samples
To preserve the rare sample, University of Maine professor Alicia Cruz-Uribe and colleagues used a specialized dating method. The technique employs a laser beam one-sixth the width of a human hair to drill holes into the sample, using helium gas to carry material into a mass spectrometer.
Francois Tissot, a geochemistry professor at Caltech, helped the researchers apply an in-situ rubidium-strontium dating technique. Tissot noted his team used a piece of meteorite smaller than a fingernail to analyze individual mineral grains.
By comparing the rock’s chemistry with orbital data from NASA’s Mars Reconnaissance Orbiter, scientists identified the southern Martian highlands—specifically the region northwest of the Hellas impact basin—as the most likely source. The mineral composition resembles material observed by the orbiter in the planet’s cratered southern highlands. NASA images of the rock show “shocked plagioclase,” which forms under the extreme pressure of the impact that originally ejected the rock from Mars into space.
Pro Tip: Geologists use zircon crystals for dating because they preserve information about a rock’s formation and help scientists determine its age.
Questions about the Martian primordial crust
How do scientists confirm a meteorite is from Mars?
Researchers compare the chemical and mineral makeup of the rock to data and samples collected by NASA’s Martian missions.
Where is the Teghaza 001 meteorite currently kept?
The primary mass of 442 grams is held at the Maine Mineral & Gem Museum in Bethel, while 22 grams of samples are held at the Institute of Meteoritics at the University of New Mexico. The Maine Mineral and Gem Museum recently loaned an additional piece to allow continued work at Caltech and UMaine’s MAGIC Lab.
Why is Teghaza 001 considered more unique than “Black Beauty”?
While “Black Beauty” is a conglomeration of many rock types, Teghaza 001 is a single, unadulterated igneous rock. Dr. Yang Liu noted that researchers have “only scratched the surface.”
Worth a look