A meteorite found in the Sahara Desert in Mali in 2022 has been shown to be one of the oldest known pieces of Mars, giving scientists a new window into the planet's ancient crust. The rock, named Teghaza 001, was studied by a team led by Yang Liu at NASA's Jet Propulsion Laboratory and shown to have formed at least 4.1 billion years ago.
Most of the Martian surface is more than 3 billion years old, according to crater counts, but the three main classes of Martian meteorites found on Earth are 2.4 billion years old or younger. Until now, only two ancient Martian meteorites were known: Allan Hills 84001, found in Antarctica, and a jumbled rock from northwest Africa called Black Beauty. Teghaza 001 is the third.
"It's very old and similar to some of the oldest rocks on Earth," Liu said.
Scientists do not fully understand why old Martian rocks are so rare on Earth. Liu said part of the answer may lie in how a rock gets here: a large impact is needed to launch it, and weak rocks do not make it off Mars. "If the impact hits into loose powder, it may not get cemented to become a rock and fly off Mars' gravity," Liu said. "So the natural impact already acts as a filter. Weak rocks do not make it off Mars."
The find provides a direct sample of Mars' early crust, offering new clues about the planet's formation and early history.
Analysis
Why This Matters
- Teghaza 001 is one of only three ancient Martian meteorites known, offering a direct sample of Mars' early crust that can help scientists understand the planet's formation and early conditions.
- The rock's age, at least 4.1 billion years, aligns with the oldest rocks on Earth and may provide clues about whether Mars was once habitable.
- The discovery highlights a gap in the meteorite record, most Martian meteorites are younger, prompting questions about the processes that deliver rocks to Earth.
Background
Martian meteorites are pieces of Mars ejected by large impacts that later fall to Earth. They are crucial for studying the planet's geology without a sample-return mission. Most known Martian meteorites are relatively young, less than 2.4 billion years old, but crater counts suggest much of Mars' surface is older than 3 billion years. Only two ancient specimens were known before Teghaza 001: Allan Hills 84001 and Black Beauty. The new find, collected in the Sahara in 2022, adds a third ancient sample.
What to Watch
- Ongoing laboratory analyses of Teghaza 001, which may reveal new details about Mars' early crust and its geochemical history.
- Search efforts for more ancient Martian meteorites in desert regions and Antarctica, which could expand the sample set.
- Theoretical work to explain the scarcity of old Martian rocks on Earth, perhaps refining our understanding of impact physics.
Checked
12 claims in this story checked against 2 sources: 12 supported.
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- SupportedThe meteorite offers a view into Mars’ ancient crust.Ars Technica - All content: “Rare meteorite from Mars gives us a view into its ancient crust.”
- SupportedTeghaza 001 is the third known ancient Martian meteorite.Ars Technica - All content: “Until now, only two genuinely ancient Martian meteorites were known: Allan Hills 84001, found in Antarctica, and a jumbled rock from northwest Africa nicknamed Black Beauty. Now we have a third one.”
- SupportedTeghaza 001 formed at least 4.1 billion years ago.Ars Technica - All content: “has shown that a Martian meteorite called Teghaza 001, found in the Sahara Desert in Mali in 2022, formed at least 4.1 billion years ago.”
- SupportedTeghaza 001 was found in the Sahara Desert in Mali in 2022.Ars Technica - All content: “a Martian meteorite called Teghaza 001, found in the Sahara Desert in Mali in 2022”
- SupportedThe study was led by Yang Liu at NASA’s Jet Propulsion Laboratory.Ars Technica - All content: “A team led by Yang Liu, a planetary scientist at NASA's Jet Propulsion Laboratory, has shown”
- SupportedCrater counts indicate that most of Mars’ surface is more than 3 billion years old.Ars Technica - All content: “Crater counts tell us that most of the Martian surface is more than 3 billion years old”
- SupportedThe three main classes of Martian meteorites are 2.4 billion years old or younger.Ars Technica - All content: “The three main classes of Martian meteorites—shergottites, nakhlites, and chassignites—are all 2.4 billion years old or younger.”
- SupportedBefore Teghaza 001, the only known ancient Martian meteorites were Allan Hills 84001 and Black Beauty.Ars Technica - All content: “Until now, only two genuinely ancient Martian meteorites were known: Allan Hills 84001, found in Antarctica, and a jumbled rock from northwest Africa nicknamed Black Beauty.”
- SupportedLiu said, “It's very old and similar to some of the oldest rocks on Earth.”Ars Technica - All content: ““It's very old and similar to some of the oldest rocks on Earth,” Liu says.”
- SupportedLiu said, “If the impact hits into loose powder, it may not get cemented to become a rock and fly off Mars' gravity.”Ars Technica - All content: ““If the impact hits into loose powder, it may not get cemented to become a rock and fly off Mars' gravity,” Liu said.”
- SupportedLiu said a large impact is needed to launch a Martian rock and that weak rocks may not make it off Mars.Ars Technica - All content: “Part of the answer may lie in how a piece of Mars gets here. It takes a large impact to launch a rock off the planet, and not every rock can survive that.”
- SupportedThe find provides a direct sample of Mars’ early crust and clues about the planet’s formation and early history.NASA: ““This is really our first piece of Martian crust from a part of Mars we’ve never had a sample of before,” said the new paper’s second author, Lee Saper”
