The Mars Reconnaissance Orbiters HiRISE camera NASA/JPL/UArizona captured a void on Mars' surface that could contain caves.
Although Mars is largely inhospitable for life, there are some ways to make it more livable. In theory, the cave entrances and surrounding areas should be protected from the radiation that bombards Mars' surface.
Mars does not have a magnetic field that is global or an atmosphere as thick as Earth's, so its surface is vulnerable to harmful ultraviolet radiation (UV) and ionising radiation. This would pose a problem for both native life and humans exploring the planet. The radiation doses that any living creature would receive on Mars' surface would be 900 times greater than those it would get on Earth.
Images from orbit show what look like cave entrances. These caverns may be shielded from the harmful rays. Daniel Videz-Moreiras, Spain's National Institute for Aerospace Technology, has calculated how much UV radiation would still reach different types of caves in various locations on Mars.
Advertisement
He discovered that the UV radiation levels inside caves was often around 2 percent of what is found on the surface. These radiation levels are safe enough to keep organisms alive, but high enough to support photosynthesis.
Although it's not clear if ionising radiation, which can be even more harmful than UV, would be blocked in the same manner, Videz-Moreiras believes it. He says that ionising radiation does not behave in the same way as UV radiation. It is possible that ionising radiation may be stronger in cave skylights and pit craters.
This has two consequences: Caves can be safe places for humans to explore Mars, but they also may be the best places to look for signs of life. Videz-Moreiras says that although no rover or lander has visited a Mars cave, it would be the best way for scientists to determine if they are habitable.
Journal reference: Icarus, DOI: 10.1016/j.icarus.2021.114658
Subscribe to the Launchpad newsletter and take a journey across the galaxy every Friday!
