By analyzing a Martian meteorite, scientists from the University of Lausanne and Curtin University have discovered traces of water dating back 4.45 billion years in the crust of Mars, i.e. to the beginning of the Red Planet’s formation. This new information reinforces the hypothesis that Mars may have been habitable at some point in its history.
Thanks to observations by Mars rovers and space probes, we’ve known for decades that Mars was once home to water, and probably rivers and lakes. But many questions remain. When did this precious liquid appear in the history of Mars? ’ Did the Red Planet, in the course of its evolution, create the conditions necessary for the emergence of life?
By analyzing the composition of a mineral (zircon) found in a Martian meteorite, scientists from the University of Lausanne, Curtin University and the University of Adelaide have succeeded in dating traces of water in the crust of Mars. According to the study, published in Science Advances, hydrothermal activity dates back 4.45 billion years, just 100 million years after the planet’s formation.
Our data suggest that there was water in the crust of Mars at a time comparable to the first traces of water on the surface of the Earth, some 4.4 billion years ago’, comments Jack Gillespie, first author of the study and researcher at the University of Lausanne’s Faculty of Geosciences and Environment. This discovery provides new elements for understanding the planetary evolution of Mars, the processes that took place there and its potential to have harbored life.
A Martian meteorite found in the desert
Scientists have been working on a small piece of meteorite NWA 7034 ’ Black Beauty ’, discovered in the Sahara desert in 2011. Black Beauty’ originates from the Martian surface, and was thrown to earth during an impact on Mars some 5 to 10 million years ago. The analysis focused on zircon, a mineral contained in the meteorite. Highly resistant, zircon crystals are key tools for dating geological processes: they contain chemical elements that make it possible to reconstruct the conditions of its crystallization: temperature, interactions with fluids, but also the date. Zircon contains traces of uranium, an element that acts as a natural clock," explains Jack Gillespie. This element decays over time at a very precise and well-known rate, changing into lead. By comparing the ratio of uranium to lead, we can calculate the age of crystal formation.
Using nanoscale spectroscopy, the team identified patterns of elements in this unique zircon, including unusual amounts of iron, aluminum and sodium. These elements were incorporated when the zircon formed 4.45 billion years ago, and their presence suggests the existence of water at the start of Martian magmatic activity.
These new discoveries reinforce the hypothesis that the Red Planet may have offered favorable conditions for life at some point in its history. This would include the presence of nutrient-rich hot springs. ’ Hydrothermal systems have been essential to the development of life on Earth, and our results suggest that Mars also had water, a key ingredient for a habitable environment, during the earliest history of crust formation’, comments co-author Aaron Cavosie of Curtin University’s School of Earth and Planetary Sciences.
Lead author Jack Gillespie, from the University of Lausanne, was a postdoctoral researcher at Curtin’s School of Earth and Planetary Sciences when he began work on the study, which was carried out in collaboration with researchers from the Curtin Space Science Technology Centre , the John de Laeter Centre and the University of Adelaide. The research is funded by the Australian Research Council, Curtin University and the Swiss National Science Foundation.
Source: J. Gillespie, A. J. Cavosie, D. Fougerouse, C. L. Ciobanu, W. D. A. Rickard, D. W. Saxey, G. K. Benedix, and P. A. Bland, Zircon trace element evidence for early hydrothermal activity on Mars , Science Advances, 2024 (DOI 10.1126/sciadv.adq3694)
