A recently discovered pit crater on Mars, possibly leading to a larger cave, has sparked excitement due to its potential to provide a sheltered environment for astronauts and hypothetical Martian life.
The intriguing pit crater on Arsia Mons was captured by the High Resolution Imaging Science Experiment (HiRISE) instrument on NASA’s Mars Reconnaissance Orbiter. This mysterious pit, located on an ancient Martian volcano, was imaged on August 15, 2022, from about 159 miles (256 kilometers) above the surface. It is part of a series of similar pits found on the flanks of three large volcanoes in the Tharsis region. The pit, situated on a lava flow on the extinct Arsia Mons, appears to be a vertical shaft. This raises questions about whether it is merely a narrow pit or the entrance to a larger cavern or a deep lava tube formed during the volcano’s active period.
Pits and caves on Mars are of significant interest for several reasons. They could offer future astronauts shelter from the planet’s high radiation levels, which are 40 to 50 times greater than on Earth due to Mars’ thin atmosphere and lack of a global magnetic field. Additionally, these pits might hold astrobiological interest as potential habitats for past or present Martian microbial life.
The presence of these pits near volcanoes suggests a connection to volcanic activity. Lava channels can create underground tubes that, when emptied and the ceiling collapses, form pits. Similar features are found on Earth, the Moon, and Mars. Some pits on Mars, like those on Arsia Mons, appear as isolated shafts, while others form pit chains along lava tubes.
The depth and structure of these pits remain uncertain. Some pits, when illuminated by the sun, reveal straight-down shafts, similar to those found on Hawaiian volcanoes, suggesting they may not open into larger caverns. However, pits on the Moon have shown evidence of larger subterranean volumes. Pits can also form from tectonic stresses or ancient underground rivers, creating geological features similar to karsts on Earth.
Future missions, potentially involving airborne vehicles like NASA’s Ingenuity helicopter, could explore these pits to provide concrete answers. If these pits do open into caves, they may become ideal landing sites for future crewed missions to Mars, offering a sheltered basecamp from the planet’s harsh radiation.
