NASA’s Curiosity rover has captured close-up images of sprawling, web-like rock formations on Mars that look like giant spider webs from orbit and could provide new clues about the Red Planet’s watery past.
The intricate formations are part of a boxwork area – network of low ridges about 1 to 2 meters high with sand pits between them – which Curiosity have been exploring for months on the slopes of Mount Sharp inside Gale Crater. The rover took panoramic images of the area with Mastcam on September 26, 2025, giving scientists an unprecedented look at the planet’s unusual terrain, according to a statement from NASA’s Jet Propulsion Laboratory (JPL).
Understanding these formations can help researchers refine timelines of when liquid water may have existed near the Martian surface—a key factor in assessing Mars’ past habitability. The web-like formations suggest that groundwater was present later in Mars’ history than previously thought, raising new questions about how long the planet may have supported conditions favorable to microbial life, according to the statement.
Until Curiosity reached the region, scientists could not confirm what these cobweb-like formations actually looked like up close or fully understand how they formed – something only a rover on the ground could solve. But getting that view wasn’t easy: the drivers had to carefully steer the nearly one-ton rover along narrow ridge lines barely wider than the vehicle itself to collect the necessary images.
“It almost feels like a highway that we can drive on. But then we have to go down into the caves, where you have to be aware that Curiosity’s wheels are slipping or having trouble turning in the sand,” Ashley Stroupe, operations systems engineer at JPL, said in the statement. “There is always a solution. It just requires trying different paths.”
Closer inspection revealed bumpy pea-sized mineral nodules embedded in ridges and hollow floors—another signature of past groundwater activity. Unexpectedly, these knots were not concentrated near the center break as predicted, but scattered along ridge walls and depressions, providing new insight into how water and minerals interacted across the Martian terrain.
Each layer of the 3-mile-high (5-kilometer-high) Mount Sharp records a distinct chapter of Mars’ changing ancient climates. As Curiosity climbs, the terrain shows a distinct shift toward increasingly drier conditions, broken up by occasional wetter intervals when rivers and lakes briefly reappear.
“Seeing boxwork this far up the mountain suggests that the groundwater level had to be quite high,” Tina Seeger, a Rice University mission scientist, said in the statement. “And that means that the water needed to sustain life could have lasted much longer than we thought, seen from orbit.”
Curiosity has also used its drill to collect stone samples from the checkout area. Analyzes of these samples have identified clay minerals on top of the ridges and carbonate deposits in the depressions – chemical clues that shed light on the environmental conditions when these rocks were formed.
Using a technique called wet chemistry — a process that uses chemical reagents to help detect organic molecules — scientists looked for signatures of carbon-based compounds linked to life in pulverized rocks collected during Curiosity’s final fourth sampling mission. The rover is expected to leave the box formations in March as it continues its ascent Mount Sharp. Exploring this region helps scientists better understand how the Red Planet evolved from a wet world to the cold, dry desert seen today.
