Since the 1960s, space agencies began sending robotic explorers to Mars to learn about the Martian surface. The general conclusion is that there was water on the planet, but a new study offers the certainty that it was covered by lakes in the ancient past.
Astronomers have reiterated that the surface of Mars had flow channels, valleys, lake beds, and deltas that appear to have formed in the presence of waterbut the goal for scientists is to know how long the water flowed in the soil, whether it was persistent or periodic in nature, and whether it existed long enough for life to emerge.
This new research, led by Dr. Joseph Michalski, associate professor in the Department of Earth Sciences and deputy director of the Space Research Laboratory (LSR) of the University of Hong Kong (HKU) indicates that, based on a meta-analysis of satellite data from years, ancient lakes may have once been a very common feature on Mars.
Water more common on Mars than we thought
It’s a statementcited in Universe TodayMichalski explained that the study focused on larger bodies of water on Mars, potentially neglecting the many smaller lakes that may have existed.
He began by comparing the lakes on Earth with those on Mars: “We know of about 500 ancient lakes deposited on Mars, but almost all of the lakes we know of are larger than 100 km2. But on Earth, 70% of lakes are smaller than this size and they are found in cold environments where glaciers have retreated.”
“These small lakes are difficult to identify on Mars by satellite remote sensing, but many small lakes probably existed. It is likely that at least 70% of Martian lakes have yet to be discovered.”
Lake beds are currently one of the top targets for robotic explorers on Mars because ancient lakes would have all the ingredients for microbial light, including water, nutrients, and energy sources such as light for photosynthesis.
Today, the lakebeds of these ancient water bodies contain sedimentary deposits rich in iron/magnesium clay minerals and carbonates, as well as sulfates, silica, and chlorides. These deposits could contain preserved evidence that would attest to ancient atmospheric and climatic conditions on Mars.
Michalski and colleagues argue that large, ancient and environmentally diverse lakes would be a much more promising target for future exploration.
“Some Martian lakes would be more interesting to microbial life than others because some of the lakes were large, deep, long-lived, and had a wide range of environments, including hydrothermal systems that could have been conducive to the formation of simple life.”.