Oldest Mars Rock Discovered in Sahara Desert Offers New Insights

One of the oldest Mars rocks ever found on Earth has been identified

One of the oldest Mars rocks ever found on Earth has been identified. The meteorite, found in the Sahara Desert in Africa, has revealed new facts about the early history of the Red Planet, according to scientific findings.

It also presents evidence that water affected the surface of Mars at least 4.1 billion years ago. According to scientists, the chemical composition of the pinkish meteorite is different and unique from other samples from Mars studied previously. Its study has provided new information about the early geological conditions of Mars, its surface, and internal structure.

Yang Liu, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, and lead author of the study, called it an extremely rare and ancient Martian meteorite.

Regarding the study published in the scientific journal Science on October 29, she said, 'This is an extremely rare and ancient Martian meteorite. It has given us the opportunity to study the early surface and interior layers of Mars. That was a time when life was just beginning on Earth.'

According to scientists, this meteorite was formed from molten material (magma) from the hot rock layer, or mantle, within the planet. Later, that material became part of the planet's outer surface, or crust.

According to Liu, its chemical composition indicates it came from a region of Mars whose rocks had not been collected and studied by scientists as samples before.

Meteorite Found in Saline Plain of Mali

'Teghaza 001', as it has been named, is named after a saline plain in the West African country of Mali. Meteorite hunters found this rock in that area in 2022.

The meteorite is made up of eight pieces. Their total weight is 798.5 grams, or about 1.76 pounds. The largest piece weighs 442 grams, or about 0.97 pounds.

According to scientists, a powerful impact caused by an asteroid or comet hitting Mars ejected the rock from Mars' weak gravity into space.

Once in space, the rock began to orbit the Sun. Possibly after orbiting the Sun for millions of years, it fell under Earth's gravitational influence and entered Earth's atmosphere.

However, scientists say it is difficult to determine exactly when the impact occurred on Mars and when the meteorite fell to Earth.

Matthew Genge, an associate professor of Earth and Planetary Science at Imperial College London, who was not involved in the study, called it a significant discovery. He said, 'It is always a pleasure to see a new visitor from Mars. It is extremely ancient. Besides being one of the oldest meteorites from Mars, it is older than any rock formed on Earth.'

He added, 'This fact in itself is very exciting. It opens a door to the earliest phase of Mars' history. That was a time when water was expected to be present on Mars.'

Accidental Study Revealed 4.1 Billion Years of History

Initial analysis by scientists did not immediately indicate that the rock was very old. Therefore, lead researcher Liu had even decided not to study it at first. She said, 'When I was first offered this sample for study, it was classified as a 'Shorgotite' type meteorite. This is the most common type of meteorite from Mars found on Earth.'

Liu had studied many Shorgotite meteorites before. About 90 percent of the meteorites identified from Mars on Earth are of this type. Typically, such meteorites are less than 600 million years old.

During the study, Liu discovered that the meteorite contained a mineral called zircon. This is a type of crystal that forms when molten rock cools and solidifies.

According to Liu, zircon can be used to determine the age of a rock. She says, 'Zircon is like a time capsule that helps us determine very accurately when a rock was formed.'

The meteorite was identified as potentially originating from 13 possible locations on Mars.

By measuring the age of the crystals, the meteorite was found to be at least 4.1 billion years old. This means the rock was formed within the first 400 million years of Mars' existence. To confirm this age estimate, researchers also used a new age-dating method developed by study co-author and doctoral candidate at the California Institute of Technology, Hewart Melton. According to Melton, the new method involves vaporizing and analyzing a very small area of the sample using a laser, rather than dissolving a large part of the rock for study.

He said, 'Using a laser, we can study samples like Teghaza 001 much faster than with traditional techniques.'

The research team used a laser beam with a diameter about one-tenth the thickness of a human hair. With its help, extremely small particles and crystals within the meteorite were analyzed.

According to Melton, this new technology has reduced the time required to measure the age of a sample from one month to one day. It also helps preserve a large part of the original sample after the study, which can be used for further research in the future.

Rock Similar to Earth's Seafloor Rocks

According to Associate Professo