This Rosy Stone Spotted in the Sahara Turned Out to Be a 4.1-Billion-Year-Old Meteorite From Mars, One of the Oldest Ever Found.
NASA-funded scientists dated a rose-colored meteorite found in the Sahara in 2022 and determined it is a piece of Mars that formed more than 4.1 billion years ago.
A rose-colored rock found in the Sahara Desert in 2022 has been identified as one of the oldest Martian meteorites ever recovered, according to NASA's Jet Propulsion Laboratory (JPL). The meteorite, named Teghaza 001 after the salt plain in Mali where it was found, weighs nearly 2 pounds (800 grams). It is one of roughly 435 known meteorites from Mars.
NASA-funded scientists age-dated its minerals and concluded the rock formed more than 4.1 billion years ago. A paper published Thursday in Science gave an initial characterization of the meteorite. A separate paper in Science Advances in June described its water content. Yang Liu of JPL, lead author of the Science paper, said: "It was only after we started looking closely that we realized this meteorite is really unique."
According to JPL, Teghaza 001 is one of the three oldest Martian meteorites found on Earth. The others are ALH84001, which is similar in age but made almost entirely of one mineral, and "Black Beauty," which formed about 2.1 billion years ago and consists of small volcanic fragments. Teghaza 001 instead holds a mix of igneous minerals that records how the crust formed from cooling magma and was later altered by subsurface water. Its mineralogy matches what NASA's Mars Reconnaissance Orbiter has observed in the southern highlands. Scientists cannot know its exact origin but identified 13 matching locations on Mars.
Researchers at the University of New Mexico had first identified the rock as Martian from its oxygen isotopes, and it appeared to be a shergottite, the most common class of Mars meteorite. Liu nearly passed on studying it, but she noticed unusual textures and minerals, including zircon crystals, which can be used to date a rock precisely. Francois Tissot of Caltech contributed a new in-situ rubidium-strontium dating method. It analyzed single mineral grains on a piece smaller than a fingernail, which preserves rare samples for future work.
The dating showed that Martian water altered the rock around 4.1 billion years ago, which suggests it formed even earlier. The team says the oxygen isotopes, texture and chemistry point to a more dynamic water cycle on early Mars. Liu said of the work so far: "We've only scratched the surface."
Note: The headline calls the meteorite 4.1 billion years old and says it was spotted. The page says it formed more than 4.1 billion years ago (water altered it around 4.1 billion years ago) and says only that it was found.
At a Glance
- Teghaza 001 was found in 2022 on a salt plain in Mali and weighs nearly 2 pounds (800 grams).
- Its minerals show it formed more than 4.1 billion years ago, and water altered it around that time.
- It is one of roughly 435 known Martian meteorites and one of the three oldest.
- Scientists identified 13 locations on Mars that match the meteorite's mineralogy and chemistry.
- The Science paper appeared Thursday, and a Science Advances paper on its water content came out in June.
Sources
This brief was written by Brightside Report from the reporting linked above. Spot an error? Request a correction.