In 2022, scientists discovered a strange rock in the Sahara Desert that may be more valuable to planetary science than initially thought. Weighing about 2 pounds, the meteorite came from the Martian crust, likely blasted into space by an impact before eventually reaching Earth. Estimated to be at least 4.1 billion years old, it is one of the oldest known samples from Mars. At that time, Earth was young and geologically active, perhaps with oceans but no animals, plants, or other complex life forms.
The Sahara is a natural archive
The discovery’s location is not entirely surprising. The Sahara Desert has long served as a natural archive of Earth’s history and the early solar system. Scientists have found 40-million-year-old fossils and other meteorites preserved in its sands. In 2019, for example, researchers discovered a 4.5-billion-year-old piece of debris that recent research suggests may have come from an extinct ancient protoplanet, perhaps roughly the size of the Moon.
The Martian meteorite, named Tegaza 001, may be part of a larger collection of Martian debris found on Earth. These rocks help scientists study Mars’ composition and geological history, although they often provide limited information about the planet’s ancient environmental conditions.
Tegaza 001 preserves evidence of ancient water
In a series of studies published in Science and Science Advances, researchers report that Tegaza 001 differs from other Martian samples. Along with its exceptional age, the meteorite preserves chemical traces of interactions between Mars’ crust and materials from the planet’s ancient hydrosphere.
“One of the paper’s reviewers called this the Rosetta Stone of Mars,” Yang Liu of NASA’s Jet Propulsion Laboratory said in a NASA press release.
This meteorite slice was used to study ancient minerals and their chemistry.
Photo: NASA/JPL-California Institute of Technology
Source: www.wired.com