Updated

Updated · Reuters · Oct 29

Teghaza 001 Reveals Water on Mars 4.1 Billion Years Ago as Oldest of 435 Known Meteorites

Updated

Updated · Reuters · Oct 29

Teghaza 001 Reveals Water on Mars 4.1 Billion Years Ago as Oldest of 435 Known Meteorites

Q: If Teghaza 001 came from the southern highlands near Hellas Basin, can scientists finally pinpoint where ancient Mars rocks reached Earth?

No. Teghaza 001 gives scientists a stronger clue, but not a final pinpointed source on Mars. The study says the meteorite likely came from the ancient southern highlands, possibly near Hellas Basin, because its age, chemistry and geologic setting fit that region. Mars’ southern highlands preserve some of the planet’s oldest crust, and Hellas is a giant impact basin where old crustal rocks could have formed and later been blasted into space. But “possibly” is the key word. Scientists usually cannot trace a Martian meteorite to one exact outcrop or crater unless they can match it uniquely to orbital data, surface geology and ejection history. For Teghaza 001, researchers have a plausible source region, not a confirmed launch site. That is still a major advance. Teghaza 001 is at least 4.1 billion years old, making it one of the oldest known Mars rocks on Earth, and it carries evidence that water moved through the crust as the rock cooled. Those features narrow the search by pointing to terrain that is both extremely ancient and altered by water. A firmer answer would require better matches between the meteorite’s mineral and chemical signatures and Mars orbital observations, along with identifying a crater young enough to have ejected it but located in very old crust. So Teghaza 001 does not finally solve the source-location problem, but it gives researchers one of their best leads yet on where some of Mars’ earliest rocks reached Earth.

3 articles · Updated · Reuters · Oct 29

Scientists dated Teghaza 001 to at least 4.1 billion years, making the Mali-found rock perhaps the oldest of the 435 Martian meteorites identified on Earth.
Hydrogen and oxygen isotope signatures show water percolated into Mars' deeper crust and mixed with mantle-derived magma as the gabbro slowly cooled.
Researchers said that evidence strengthens the case that early Mars was warmer, wetter and potentially habitable for microbes, though it does not show life existed there.
Only three known Martian meteorites come from the planet's earliest history, making Teghaza 001 a rare lab sample for tracing how Mars diverged from Earth after both formed about 4.5 billion years ago.