NASA’s Perseverance rover recently snapped an impressive photo of large sand formations on Mars called “megaripples.” This image, captured on August 13 at a location named Kerrlaguna, shows how Martian winds continue to shape the landscape.
Megaripples are sandy ridges about three feet high. They are nestled between smaller ripples and larger sand dunes. Many of these formations are believed to date back to a time when Mars had a thicker atmosphere and stronger winds, suggesting significant climate changes over millions of years. Some megaripples even show fractured crests, hinting at their long exposure to changing conditions.
At Kerrlaguna, the megaripples are classified as “inactive,” meaning they haven’t visibly moved in recent years. Unlike Earth’s ripples, which are constantly shifting due to wind and water, Martian megaripples consist of fine sand layered with coarser grains that make them more resistant to movement. Nevertheless, research indicates that some megaripples do move, albeit slowly — about one meter every nine Earth years. This reveals that Mars is still geologically active, countering earlier beliefs that the planet was lifeless.
Jim Zimbelman, a planetary geologist, noted that high-resolution images have helped scientists track these movements over time. Most notable changes happen in the northern polar region of Mars, where seasonal carbon dioxide ice temporarily stabilizes the sand formations. As spring arrives, the ice sublimates, allowing wind to kick the sand back into motion.
Perseverance is equipped with various instruments, including cameras and tools for analyzing soil and rock chemistry. This helps scientists understand the size and layering of sand grains and detect salty crusts that might have formed over time. These crusts could provide hints about past water activity and even be useful resources for future human missions to Mars.
Earlier in its mission, Perseverance tried to navigate a rocky slope toward a site called Midtoya but had to turn back due to challenging terrain. However, the rover still managed to analyze rocks along the way, including one with a striking shape that reminded people of a medieval helmet. This quirky find captured attention online and showed how even setbacks can lead to interesting discoveries.
Mars has a history of studies on its sand formations. Almost a decade ago, the Curiosity rover observed dynamic dunes at “Namib Dune” and captured a memorable selfie there. While active dunes provide insights into surface changes, megaripples like those at Kerrlaguna offer valuable clues about Mars’ climatic history.
Looking ahead, Perseverance is set to head toward “Lac de Charmes,” where a larger field of megaripples awaits. This ongoing investigation is crucial, as it sheds light on Mars’ current environment and prepares for potential future exploration.
For more information on these scientific endeavors, visit NASA’s official website.
