NASA Identifies 4.1 Billion Year Old Martian Meteorite

A meteorite recovered from Mali's Sahara Desert has provided NASA scientists with an unusually old sample of Mars, dating back approximately 4.1 billion years. Named Teghaza 001, the nearly two-pound, rose-colored rock offers evidence of how the planet's early crust formed and interacted with water.

The meteorite was discovered in 2022 on a salt plain in Mali, which inspired its name. According to NASA, laboratory analysis identified it as one of approximately 435 meteorites from Mars known to have reached Earth.

Researchers established its Martian origin by comparing its chemical and mineral composition with samples and scientific data collected through NASA's missions to the Red Planet. Age-dating results placed it among the three oldest Martian meteorites discovered on Earth.

Yang Liu, the lead author of a research paper examining the meteorite, said its distinctive characteristics became apparent through detailed investigation.

"It was only after we started looking closely that we realized this meteorite is really unique. One of the paper's reviewers called it a Rosetta Stone for Mars," said Liu, a researcher at NASA's Jet Propulsion Laboratory in Southern California.

Unlike earlier ancient Martian meteorites, Teghaza 001 preserves evidence of both the formation of Mars' crust through cooling magma and subsequent changes caused by surface water. NASA described the discovery as a rare opportunity to examine the planet's early geological history.

The rock contains an unusual combination of volcanic minerals, including zircon crystals. NASA researchers found similarities between its mineral composition and samples observed by the agency's Mars Reconnaissance Orbiter in the southern Martian highlands.

Francis Tissot, a geochemistry professor at Caltech, helped develop the analysis using an advanced age-dating technique. The method allowed researchers to examine individual mineral grains in a meteorite fragment smaller than a fingernail.

The results indicated that Martian water had altered the rock approximately 4.1 billion years ago. NASA noted that the meteorite itself could have formed even earlier, while the findings suggest early Mars may have experienced a more active water cycle than previously understood.

Lee Saper, another author of the research paper, highlighted the geological and atmospheric evidence preserved in the sample.

"It records interactions of water and rock and maybe even an imprint of the Martian atmosphere as it was losing water," said Saper.

A separate study published in June examined the meteorite's water content and explored how water may have influenced the topography of early Mars. Together, the investigations provide additional evidence about environmental conditions during the planet's earliest geological period.

Saper, a scientist at NASA's Ames Research Center, also emphasized the significance of the sample's geographic origin on Mars.

"This is really our first piece of Martian crust from a part of Mars we've never had a sample of before," Saper said.

Further investigation is expected to examine additional information preserved in the meteorite. Liu said the existing research represents only an initial examination of its scientific potential.

"We've only scratched the surface," Liu said.