Mars’s rugged landscape has revealed a network of geological formations resembling spiderwebs, prompting renewed scientific inquiry into the planet’s watery past and the potential for ancient microbial life. NASA’s Curiosity rover, currently exploring a region characterized by these unusual structures, has been documenting the formations for approximately six months.
The features, dubbed “boxwork,” consist of low ridges standing between three and six feet tall, interspersed with sandy hollows. These formations stretch for miles across the Martian surface and were initially observed from orbit, where their web-like pattern became apparent. Close-up images captured by Curiosity’s Mastcam on September 26, 2025, provide unprecedented detail of the structures.
Scientists theorize that the boxwork formed as groundwater flowed through fractures in the bedrock, depositing minerals that strengthened the ridges. Over time, wind erosion removed the softer, unreinforced material, leaving behind the distinctive, interconnected network. The discovery suggests that groundwater persisted on Mars later than previously believed, potentially extending the window for habitable conditions.
“This possibility raises new questions about how long microbial life could have survived on Mars billions of years ago, before rivers and lakes dried up and left a freezing desert world behind,” NASA stated in a press release issued February 23, 2026.
Further investigation by Curiosity revealed pea-sized nodules along the walls of the ridges and within the hollows. These bumpy features, captured by the rover’s Mars Hand Lens Imager (MAHLI) on August 21, 2025, are believed to have formed from minerals deposited as groundwater evaporated. The presence of these nodules confirms repeated instances of groundwater activity in the region.
Previously, dark lines observed in orbital images of the boxwork formations were a source of mystery. Curiosity’s close-up observations have now confirmed that these lines are central fractures where minerals concentrated, a finding that clarifies the formation process.
While similar boxwork ridges exist on Earth, they are typically much smaller, rarely exceeding a few centimeters in height and are usually found in caves or arid environments. The scale of the Martian formations is therefore particularly noteworthy.
The ongoing exploration of the boxwork formations is expected to continue as Curiosity moves further into the region, with scientists anticipating further insights into the Red Planet’s geological history and potential for past life.