Life may have emerged on Mars and Earth at the same time. That's according to new evidence found in a Martian meteorite that indicates the key ingredient for life, water, appeared on Mars around 4.4 billion years ago, when scientists know, from other research, that it appeared on Earth.
Scientists have known for decades that Mars held water, with strong geological signs of ancient rivers and lakes etched onto its landscape. However, researchers did not know when water first appeared on Mars or how, after it had appeared, it might have created the conditions for life to emerge.
There were traces of water in the Martian crust at the same time this occurred on Earth, according to the findings of a team of scientists who have analyzed the makeup of a mineral called zircon that was found in the Martian meteorite.
"Our data suggests the presence of water in the crust of Mars at a comparable time to the earliest evidence for water on the Earth's surface, around 4.4 billion years ago," said Jack Gillespie of the University of Lausanne's Faculty of Geosciences and Environment. He led the new research, published in the online journal Science Advances, with colleagues at Australia's Curtin University and the University of Adelaide.
"This discovery provides new evidence for understanding the planetary evolution of Mars, the processes that took place on it and its potential to have harbored life," Gillespie said.
Martian Meteorite in the Desert
The meteorite under study, nicknamed "Black Beauty," was discovered in the Sahara Desert in 2011. It is thought the rock was fired off the Mars surface following an impact there and thrown to Earth, sometime between 5 million and 10 million years ago.
The scientists focused on the zircon that was contained in the meteorite. That is because zircon crystals contain elements that make it possible for geologists to reconstruct the date and conditions under which they crystallized or formed.
"Zircon contains traces of uranium, an element that acts as a natural clock," Gillespie said. "This element decays to lead over time at a precisely known rate. By comparing the ratio of uranium to lead, we can calculate the age of crystal formation."
The scientists identified unusual amounts of iron, aluminum and sodium that came together to form this magmatic rock 4.45 billion years ago. The chemical makeup of the rock suggested that water was present during the Martian magmatic activity that made the rock.
These latest findings support the idea that Mars once had hot water vents or springs that were favorable to the formation of life at some point in its history—similar to what happened on Earth.
"Hydrothermal systems were essential for the development of life on Earth, and our findings suggest Mars also had water, a key ingredient for habitable environment, during the earliest history of crust formation," said Aaron Cavosie, who is at Curtin University's School of Earth and Planetary Sciences and took part in the research.
Reference
Gillespie, J., Cavosie, A. J., Fougerouse, D., Ciobanu, C. L., Rickard, W. D. A., Saxey, D. W., Benedix, G. K., & Bland, P. A. (2024). Zircon trace element evidence for early hydrothermal activity on Mars. Science Advances, 10(47), eadq3694. https://doi.org/10.1126/sciadv.adq3694
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