A tiny grain from a Martian meteorite known as Black Beauty suggests Mars may have been capable of supporting life.
Researchers in Australia have uncovered what they said may be the oldest direct evidence of ancient hot water activity on the red planet.
The scientists said the find shows Mars may have been habitable at some point.
Their study, published in the journal Science Advances, involved the analysis of a 4.45 billion-year-old grain of zircon from the Martian meteorite NWA7034, called Black Beauty.
The research team led by scientists at Curtin University, Perth, found geochemical “fingerprints” of water-rich fluids.
Study co-author Dr Aaron Cavosie of Curtin’s School of Earth and Planetary Sciences said the discovery opened up new avenues to understanding ancient Martian hydrothermal systems and the planet’s habitability in the past.
Dr Cavosie explained researchers used nano-scale geochemistry to detect elemental evidence of hot water on Mars billions of years ago.
He added: “Hydrothermal systems were essential for the development of life on Earth and our findings suggest Mars also had water, a key ingredient for habitable environments, during the earliest history of crust formation.”
Using nano-scale imaging and spectroscopy, scientists identified elements in the zircon grain, including iron, aluminium, yttrium and sodium.
These elements were added as the zircon formed 4.45 billion years ago, suggesting water was present during early Martian magma activity.
Dr Carvosie said the study showed even though Mars’ crust endured “massive” meteorite impacts, causing major surface upheaval, water was present during the early Pre-Noachian period, before about 4.1 billion years ago.
He added that a 2022 Curtin study of the same zircon grain found it had been “shocked” by a meteorite impact, marking it as the first and only known shocked zircon from Mars.
The expert said: “This new study takes us a step further in understanding early Mars, by way of identifying tell-tale signs of water-rich fluids from when the grain formed, providing geochemical markers of water in the oldest known Martian crust.”