Ancient Martian Meteorite Discovered in Sahara Sheds Light on Early Water
Scientists have identified a 4.1-billion-year-old meteorite from Mars in the Sahara, offering new data on the planet's early crust and water loss.
A meteorite recovered from the Sahara Desert has been confirmed as a 4.1-billion-year-old fragment of Mars, making it one of the oldest Martian rocks found on Earth. Named Teghaza 001 after a nearby abandoned settlement in Mali, the stone was first spotted four years ago and later re-examined after zircon crystals—unusual for typical Martian shergottites—were detected.
Using uranium isotope ratios and two additional dating methods, researchers dated the zircons to about 4.1 billion years, establishing Teghaza 001 as an exceptionally ancient sample. The rock, weighing roughly two pounds before breaking into eight pieces during atmospheric entry, is believed to have been ejected from Mars by an impact event before traveling to Earth.
“It’s very rare to find something this old,” said Yang Liu, a planetary scientist at NASA’s Jet Propulsion Laboratory and lead author of the study.
The meteorite’s mineral composition differs from that of other Martian samples, providing a unique window into the planet’s early crust and mantle. Geoscience professor Arya Udry, who was not involved in the research, noted that the mineralogy is not represented in the existing Martian collection.
Analyses also revealed water molecules trapped within apatite crystals, suggesting that water was abundant when the rock formed but that Mars had already begun losing it. The study found elevated deuterium levels, indicating significant hydrogen escape to space. Comparisons with the Allan Hills 84001 meteorite show similar deuterium-to-hydrogen ratios.
“It’s not completely changing our view of Mars at that time, but now we have two data points instead of one, which gives us a lot more confidence,” said Lee Saper, a planetary scientist at NASA’s Ames Research Center and co-author.
While the exact ejection and landing dates remain unknown, the research team identified 13 potential source regions on Mars by matching the meteorite’s composition with orbital spacecraft data. Further analysis of Teghaza 001 could uncover additional details about Mars’s early geological history.
“We looked at a small part of it. There’s a much more complex story that’s yet to be uncovered,” Saper added.