Scientists have discovered a completely new type of rock from Mars and, for the first time, identified the mineral garnet in a Martian sample.
The finding offers an exciting glimpse into the Red Planet’s distant past and could help researchers better understand how Mars evolved over the past 4.5 billion years.
The discovery was made by an international team of scientists that included Professor James Darling, an Earth and planetary scientist from the University of Portsmouth in the United Kingdom.
On Earth, garnet is best known as a deep red gemstone often used in jewelry and is the birthstone for January. However, for geologists, garnet is much more than a beautiful gem.
The mineral can preserve valuable information about the temperatures, pressures and geological events that shaped rocks long ago.
The newly discovered garnet-bearing rock may act like a time capsule from ancient Mars. By studying it, scientists hope to uncover clues about the processes that helped shape the planet billions of years ago.
The research was led by Professor Tanya Kizovski from Brock University in Canada. She said the discovery expands scientists’ understanding of the kinds of geological processes that may have occurred on Mars.
The team found the garnet while studying a small fragment of a Martian meteorite called NWA 8171, which is part of the collection at the Royal Ontario Museum in Canada. At first, the researchers thought the unusual fragment contained pyroxene, a common mineral found in many rocks.
But something about its chemical makeup seemed unusual.
“This little section of the meteorite looked really interesting, and the chemistry was a bit odd,” Kizovski said. “At first, we assumed it was pyroxene, but then we decided to take a second look.”
Using advanced microscopes and specialized laser equipment, the researchers were surprised to discover that the fragment actually contained garnet—a mineral that had never before been identified in a Martian sample.
The scientists then began investigating how the garnet may have formed.
On Earth, garnet is commonly found in metamorphic rocks. These rocks form when existing rocks are transformed by intense heat, high pressure or hot fluids. Similar conditions could also have occurred on Mars.
The researchers suggest that the necessary heat and pressure may have been created when a large meteorite struck the Martian surface, when magma rose through the crust, or perhaps through a combination of both events.
However, the team cannot yet say with certainty that the garnet formed on Mars. There is also a possibility that the rock came from another planetary body and later reached Mars through a meteorite impact.
To solve the mystery, scientists would need to study the rock’s oxygen isotopes, which can reveal where it originally formed. The problem is that such tests would require destroying part of the sample.
Because this may be the only garnet-bearing Martian rock available for study, researchers are proceeding carefully. They hope that future analyses, combined with data collected by Mars rovers and orbiting spacecraft, will eventually reveal the true origin and history of this remarkable piece of the Red Planet.
Source: University of Portsmouth
