Sahara Desert Meteorite Identified as 4.1-Billion-Year-Old Martian Crust
A rose-colored meteorite discovered by nomadic meteorite hunters in the Sahara Desert of Mali in 2022 has been identified as a 4.1-billion-year-old fragment of the Martian crust, according to a study detailed by NASA and published in Science.
Weighing nearly two pounds, the rock was named Teghaza 001 after the salt plain where it was located. NASA scientists determined the specimen is one of roughly 435 verified meteorites originating from the Red Planet. Researchers verified its Martian origin by comparing its chemical and mineral makeup against data and samples collected by NASA’s Martian missions.
Age-Dating Teghaza 001 With Single Mineral Grains
Age-dating analysis places the rock at roughly 4.1 billion years old, establishing it as one of the three most ancient Martian meteorites ever found on Earth, according to NASA. The only other known intact ancient sample, discovered in Antarctica during the 1980s, is just 10 million years younger than Teghaza 001.
To achieve this precision, researchers utilized a novel technique. Francois Tissot of Caltech helped the team apply an in-situ rubidium-strontium age-dating method using a piece of the meteorite smaller than a fingernail. This approach analyzes single mineral grains on the surface without dissolving the entire sample, preserving rare material for future analysis.
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,
Tissot said.
Evidence of an Ancient Water Cycle and Pre-Noachian Mars
The meteorite provides a rare snapshot of Mars during the Pre-Noachian period, spanning roughly 4.5 to 4.1 billion years ago. Carl Agee, director and curator at the University of New Mexico’s Institute of Meteoritics, said the sample comes from an environment that was likely more Earth-like.
If there was ever abundant life on Mars, on the surface, not sequestered away in some subsurface, that would be the time that you would be looking at, the Pre-Noachian period,
Agee said.
Analysis of manganese and hydrogen trapped inside Teghaza 001 shows the rock was altered by Martian water about 4.1 billion years ago, indicating that early Mars featured a dynamic water cycle. At the same time, the data suggests the planet was already losing its atmosphere and transitioning toward its current cold, dry state.
Questions About the Ancient Red Planet
Where on Mars did Teghaza 001 originate?
Scientists do not know the exact region of Mars where the meteorite came from. Because its chemistry and texture differ from younger Martian meteorites, researchers believe it may have originated from an underrepresented area where rovers have not yet explored.
How does Teghaza 001 compare to Earth’s oldest rocks?
Lead study author Yang Liu, a planetary scientist at JPL and Caltech, noted that researchers are holding a piece of a rock dated even before the oldest known Earth rock, existing from a time when life had just started on Earth.
What makes the meteorite’s mineral composition unique?
The rock contains zircon crystals that record clues to a rock’s formation and can be used by geologists to precisely age-date a sample.