Meteorite found in the Sahara is one of the oldest pieces of Mars ever found, NASA-funded study says
Scientists dated minerals in Teghaza 001, found in 2022, and say the rock formed more than 4.1 billion years ago and records water interacting with ancient Martian crust.
A rose-colored meteorite found in the Sahara Desert in 2022 is a piece of Mars that formed more than 4.1 billion years ago, making it one of the oldest Martian meteorites ever found, according to NASA.
The rock weighs nearly 2 pounds (800 grams) and is named Teghaza 001, after the salt plain in Mali where it was discovered. NASA said it is one of roughly 435 known meteorites from Mars. NASA-funded researchers gave an initial description of it in a paper published Thursday in the journal Science. A separate paper published in Science Advances in June described how much water the meteorite contains.
Researchers at the University of New Mexico first identified the rock as Martian from its oxygen isotopes, NASA said. It looked like a shergottite, the most common type of Martian meteorite. Lead author Yang Liu of NASA's Jet Propulsion Laboratory almost passed on studying it, but she then found odd textures, unusual minerals and zircon crystals, which can be used to date a rock precisely.
Caltech coauthor Francois Tissot's team dated single mineral grains on a piece smaller than a fingernail. The results showed the rock had been altered by Martian water around 4.1 billion years ago, which suggests it formed even earlier.
“"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."”Yang Liu, lead author, NASA Jet Propulsion Laboratory
Why it matters: NASA said the find gives a rare look at the ancient crust of Mars and how it formed. According to NASA, the meteorite's mix of volcanic minerals shows how crust formed from cooling magma and was later altered by water underground. Its minerals match what NASA's Mars Reconnaissance Orbiter has seen in the planet's cratered southern highlands. Clues in the rock point to a much more active water cycle on early Mars, the agency said.
Second author Lee Saper, now at NASA's Ames Research Center, called it "our first piece of Martian crust from a part of Mars we've never had a sample of before." Tissot said his lab is among very few able to do this kind of dating, and he hopes the method can be used on more Martian meteorites and on samples brought back from other worlds.
What is not known: According to NASA, no one will ever know exactly where on Mars the meteorite came from, though the paper lists several possible locations that match its makeup. Future studies may help answer questions such as how water and rock interacted on ancient Mars.
"We've only scratched the surface," Liu said.
