Relics of an ancient sandstorm on Mars point to Earth-like winds: Curiosity rover finds what may be the first direct evidence that Mars once had a thick atmosphere.

The article focuses on the discovery by NASA's Curiosity rover of fossilized sand ripples on Mars, which may provide the first direct evidence that the planet once had a thicker atmosphere. These ancient ripples, found in 3.6-billion-year-old rocks in Gale crater, are identified as supercritical climbing ripples, indicating strong winds capable of transporting large amounts of sand. Researchers suggest that such wind patterns imply a denser atmosphere than Mars has today, which could have supported liquid water and influenced the planet’s climate history. However, some scientists caution that the ripple formations might also result from Mars’s unique atmospheric and gravitational conditions rather than atmospheric thickness alone. This finding offers a potential new method for estimating ancient Martian atmospheric pressure, contributing to the understanding of Mars’s transition from a wetter environment to its current arid state. [Extracted from the article]