14 DAY TRIAL // Astronomers studying pictures sent back by the Mars Reconnaissance Orbiter (MRO), currently circling the Red Planet, say that an intriguing clump of depressions in the Martian soils could be the entries to an underground cave system. The underground refuges could be supporting microscopic life forms that were driven away from the surface when the planet lost its water, billions of years ago. In the future, as space agencies ponder manned explorations to the planet, these underground caverns could prove to be a wonderful refuge in which astronauts could take shelter from the harsh conditions on the surface of Mars, Space reports.
US Geological Survey (USGS) physicist Glen Cushing reveals that depressions such as the ones in the recent MRO photos were observed on the Martian surface before. However, the recent observations are the first to show the peculiar formations in more detail, which led planetary scientists to the conclusion that they might be in fact entrances to underground caves. “What's special about these [new features] is that they are closer to the surface and smaller [than previous ones],” the expert says.
MRO snapped the high-resolution photos in extinct lava flows around the volcano Arsia Mons. The images seem to reveal tunnel-like structures below the skylight-looking depression mouths. Each of them is about 62 miles (100 kilometers) long and 330 feet (100 meters) wide. Cushing argues that the structures were formed when layers of cooled material were deposited atop a lava channel. This happened billions of years ago, during an active volcanic eruption. At some point in time, after the lava froze over, sections of the tunnel's ceiling collapsed, creating the skylight-like entrances that were detected by the orbiter's instruments.
“Caves can protect human explorers from a range of dangerous conditions that exist on Mars' surface. If caves are not used for long-term human habitation, then explorers must either transport substantial shelters of their own or build them on site,” the expert shares. Some of the most dangerous threats on Mars include radiation, extreme temperatures and dust storms, and “caves really protect from all of these things,” Cushing adds. “Caves are probably among the only places on Mars where you can actually look and see if there's possible evidence of past life.”
Existing assets on the surface of Mars, such as the Spirit and Opportunity rovers, are too far away from these structures to visit them, and it would probably take decades for them to cover the necessary distance between their current locations and Arsia Mons. But Cushing believes that future exploration missions will have these caves as a primary destination. “Someday robot explorers will probably visit caves such as these and show us a whole new hidden world,” he concludes.