Scientists narrow a Mars rock's home to 13 possible craters

NASA has marked 13 places on Mars that could be the birthplace of Teghaza 001, a meteorite with a minimum age of about 4.1 billion years ^[3], and every one of them points to the planet's southern highlands ^[1].

It is a narrowing, not a pin on a map. NASA's own description says the evidence links the rock to the southern hemisphere highlands but cannot establish its exact origin ^[1]. Even so, it hands planetary scientists something rare: a lab sample tied to a region of ancient Martian crust.

The work was published in Science on October 29, 2026, under the title "A Martian meteorite that formed ≳4.1 billion years ago samples Mars' early crust and mantle" ^[3]. NASA released its map the same day.

A rock from the desert

Teghaza 001 was found in the Sahara Desert in Mali in 2022. It came as eight stones with a combined mass of nearly 800 grams, less than a kilogram of rock ^[3].

Researchers at the University of New Mexico confirmed it came from Mars by measuring its oxygen isotopes, the slightly different weights of oxygen atoms that act as a signature for where a rock formed. Each planet and large body in the solar system has its own signature ^[3]. They also used an electron microprobe, an instrument that reads the chemistry of a rock at tiny scales ^[3].

The age came later. Researchers dated tiny zircon crystals inside the rock by measuring uranium and the lead it decays into, which works like a clock that starts when the crystal forms ^[3]. The result is a minimum age of about 4.1 billion years ^[3].

The rock is a gabbroic diorite, and it is one single rock type ^[3]. That sets it apart from Black Beauty, another famous Martian meteorite, which is a jumble of different rock types ^[3].

A single, coherent rock is easier to read. It is a piece of one place.

"This is just one single meteorite," said UNM researcher Carl Agee. "It's like going out back in time and chipping off a hunk of an outcrop, 4 billion years ago on Mars, and then we have this example of what was actually happening." ^[3]

How you trace a rock home

The method is a kind of fingerprint match, run in reverse. Orbiting spacecraft measure what the surface of Mars is made of from above. The meteorite, sitting in a laboratory, can be measured far more precisely. The question is where on the planet the two agree.

The study's authors compared the meteorite's potassium, thorium, silicon and iron with remote-sensing observations of the Martian surface to find possible source regions ^[3]. NASA says researchers used data from the Mars Reconnaissance Orbiter to find the matching areas ^[1]. The base of the global map is built from elevation data gathered by the Mars Orbiter Laser Altimeter on Mars Global Surveyor ^[1].

The leading match, according to the study text indexed by Science, lies in the Noachian southern highlands, particularly northwest of Hellas impact crater ^[3]. Hellas is one of the largest impact basins on Mars. The highlands are ancient crust, a record of the planet's early evolution ^[3].

That last point is what makes the result useful beyond one rock. UNM says that identifying the likely source region could help guide future landers, rovers or sample-return missions investigating Mars's ancient crust ^[3].

Why 13 and not one

The limit is built into the method. Orbiters can compare surface composition with a meteorite, but they cannot show which specific impact threw it into space. A rock that matches a patch of ground on Mars may match the ground around it too. Thirteen candidates is what the chemistry allows.

The rock itself carries a record of the violence that freed it. NASA's image of a cut slice shows iron-titanium oxides, pyroxene and shocked plagioclase, a mineral that forms under extreme pressure ^[2]. NASA says the plagioclase was shocked during the impact that launched the meteorite toward Earth ^[2]. So the rock bears the mark of the crater it left behind, which no one can yet point to.

It also records something gentler. Teghaza 001 contains altered minerals and unusual oxygen-isotope signatures that the researchers interpret as evidence of interaction with fluids on Mars ^[3]. That is evidence about the planet's early environment. It is not evidence of life, and the study does not claim it is ^[3].

What it means

Mars has two kinds of evidence, and they rarely meet. Orbiters see whole regions but cannot hold a rock. Meteorites can be cut, dated and weighed, but they arrive with no address. Teghaza 001 now has a partial one.

That matters for a practical reason. Sample-return missions are expensive and every landing site is a bet. A meteorite that says "the ancient crust looks like this" is a way to check, from the lab, what a lander would find in the highlands. The 13 sites are a shortlist of places where that check could be tested.

The open questions are plain. Researchers have not said whether the 13 sites can be told apart, or which features at each best explain the rock's chemistry. Further analysis of the meteorite should also say more about when and how water altered it on early Mars.

For now, the rock is still in the lab and the crater is still on Mars. The next step is to see whether anyone can shrink the list.