A NASA rover discovers evidence that Mars had more than just lakes.
"Possibilities of microbial habitability."
The Curiosity rover, the size of a car, has discovered evidence that in the past, Mars may have provided quite favorable conditions for life. Images taken by the NASA robot show dry lake beds and ripple formations on its ancient shores. According to planetary scientists, these ripples were likely created by small waves in lakes that were not covered by ice, suggesting that Mars was a warm, wet, and habitable planet during a period when, according to some studies, it began to cool and transform into a dry, frozen desert. These formations date back approximately 3.7 billion years, a time that coincides with the appearance of the first known fossils on Earth, which emerged about 3.5 billion years ago.
Claire Mondro, a postdoctoral researcher at Caltech focusing on Mars' history and leading the new study, pointed out that the time during which liquid water existed on the planet increases the chances for microbial habitability in its later history. The study was recently published in a peer-reviewed scientific journal. Currently, Mars is a thousand times drier than the most arid desert on Earth. Although there is still no evidence of primitive life on Mars, it has been clarified that the planet had watery environments conducive to the possible formation of microbes.
The signs of the ripples underscore that those shallow lakes, which could measure between 200 to 500 meters wide, were bodies of water exposed to the air, suggesting conditions favorable for life. Mondro explained that "the shape of the ripples could only have formed under water that was open to the atmosphere and subjected to wind action." The images demonstrate these ancient ripples, which have been preserved as Martian rocks, with a height of approximately six millimeters.
Despite Mars once having abundant water, the planet gradually lost its protective atmosphere, partly due to solar radiation and a weakened magnetic field. This deterioration led to the thinning of the thick atmosphere and large amounts of water escaping into space, resulting in a dry planet. However, Mars had the opportunity to host life in lakes and in the moist sediments of river deltas for millions of years. NASA plans to retrieve Martian rock samples in the 2030s, hoping that these may reveal evidence of past life on the surface. While it could be that life never existed on its surface, it is possible that it thrived, or even still exists, in the depths of the soil, protected from the harsh desert conditions and radiation.
