This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Scientists at the University of New Mexico have played a key role in identifying a rare, 4.1-billion-year-old Martian meteorite that provides new evidence that the red planet may have once had a wetter, Earth-like environment. The discovery, titled "A Martian meteorite that formed ≳4.1 billion years ago samples Mars' early crust and mantle" and published in the journal Science, provides an unprecedented look at Mars' earliest geological history that could help guide future exploration of the planet.
Scientist Carl Agee, director and curator at UNM's Institute of Meteoritics (IOM), has long studied the origin and evolution of planetary interiors and their differentiation. After receiving meteorite samples recovered from the Sahara Desert, he began examining one of them, now known as Teghaza 001 (Teg 001), and recognized unusual textural, mineralogical and compositional features not typically seen in Martian meteorites. These characteristics were somewhat similar to another famous Martian rock Agee studied, Black Beauty, a water-rich meteorite linked to the Martian crust.
Agee's experience analyzing and noting something unusual in this sample led to further scientific detective work to pursue the mystery. Using UNM's electron microprobe and oxygen isotope analysis capabilities at UNM's Center for Stable Isotopes, Agee and colleague Karen Ziegler, a scientist in the IOM and research professor in the Department of Earth and Planetary Sciences, examined the meteorite more closely and identified characteristics that distinguished it from previously studied specimens, including high levels of manganese oxide, a common byproduct of microbial life. "I realized that this one was a little bit like Black Beauty, not exactly, but it resembled it in the oxygen isotope values," said Agee, who thought this meteorite might be something special.
"I looked at it microscopically and found domains within it that had high levels of manganese oxide, a compound being looked for on Mars by the rovers as an indicator of environments conducive to life." UNM's expertise in meteorite identification and analysis helped initiate a research effort that produced a significant planetary science discovery. The findings led to a collaboration with scientists at NASA's Jet Propulsion Laboratory, Caltech's Division of Geological and Planetary Science Analytical Facility, UCLA's Department of Earth, Planetary, and Space Sciences, and the University of Maine's School of Earth and Climate Sciences. Scientists, including NASA JPL's Yang Liu, whose research focuses on extraterrestrial rocks and soils using microbeam methods, along with scientists at Caltech, conducted additional testing and discovered tiny zircon crystals that allow age-dating of igneous rocks.
Using uranium-lead age analyses to date the tiny zircon crystals, Liu dated the meteorite to 4.1 billion years old, making it the oldest known Martian lava rock identified to date, according to Agee. "There are a few parts to Black Beauty that are around that age, but that whole meteorite itself is a conglomeration of many different rock types. Teghaza 001 is just one unadulterated rock type, and it's 4.1 billion years or older, so that was a big surprise," said Agee.
"It's the oldest Martian igneous rock ever found by a huge margin, but in addition to that, it seemed to have these clues in its composition that suggested it had been in an environment that had fluids and water coursing through it." Unlike most Martian meteorites, which formed hundreds of millions of years ago, Teg 001 dates to the earliest stages of the planet's formation. Its composition consists of a single rock type, unlike other known Martian meteorites such as Black Beauty, offering a unique glimpse into Mars and a rare opportunity to study the planet's ancient crust and geological evolution. Discover the latest in science, tech, and space with over 100,000 subscribers who rely on Phys.org for daily insights. d research that matter—daily or weekly.
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