Entrances to Martian Caves May Provide Perfect Radiation Shelter for Human Settlements

There are very good reasons why Mars is such a desolate and barren landscape. Without a thick atmosphere or magnetic field, the surface of the Red Planet is bombarded daily with radiation up to 900 times greater than that observed on Earth. However, some places are sheltered. New research has shown that cave entrances are protected from the harmful radiation that normally strikes Mars. This can make them ideal both as sites for future colonies and robotic missions meant to search for signs of alien life.

Despite the incredible advances in space exploration over the past decade, if we are to take the idea of ​​installing Mars seriously in this century, there are many challenges that must be overcome. That’s unless we settle for one-sided suicide missions.

There is no shortage of environmental dangers to kill any astronaut daring enough to dare to set foot on Mars. On the one hand, the planet has only 0.7% of the pressure at sea level of Earth, which means that any human on Mars must wear a full pressure suit or remain barricaded inside it. ‘a pressure-controlled chamber, otherwise oxygen will not flow into the bloodstream and the body may swell and bleed.

Then there is the issue of radiation. Mars is farther from the Sun than Earth, receiving about 60% of the power per square meter seen at a similar site on Earth. But since Mars has no magnetic field to deflect energetic particles, coupled with an atmosphere as thin as paper, its surface is exposed to much higher radiation levels than Earth. In addition, besides regular exposure to cosmic rays and solar wind, it occasionally receives deadly radiation blasts from strong solar flares.

Measurements made by the Mars Odyssey probe suggest that current radiation levels on Mars are at least 2.5 times higher than those felt by astronauts on the International Space Station. That’s about 22 millirads per day, which works out to 8,000 millirads (8 rads) per year. For comparison, people in the United States are exposed to about 0.62 rads / year on average.

Any attempt to colonize the Red Planet will require measures to ensure that radiation exposure is minimized. Some of the ideas proposed so far relate to habitats built directly into the ground or even aerial habitats using ceramic coated inflatable modules.

But a better idea may be to take advantage of the natural shelters already in place. Mars is dotted with deep pits, caves, and lava tube structures on its surface. Many of these caves could offer sufficient protection to human settlers, according to a new study by researchers led by Daniel Viúdez-Moreiras of the Spanish National Institute of Aerospace Technology.

“The caves and their entrances were proposed as environments and habitable regions that could have preserved evidence of life, primarily due to their natural protection from harmful ionizing and non-ionizing radiation present on the surface. However, no study to date has quantitatively determined the shielding offered by these voids on Mars, ”the researchers wrote in the journal. Icarus.

The researchers found that UV radiation levels inside Martian caverns were, in some cases, about 2% of those values ​​found on the surface.

“Numerical simulations of cave entrances show a reduction of more than two orders of magnitude in UV radiation, both in instantaneous and maximum cumulative doses, throughout the year and at any place in the world. planet “, the researchers discovered.

In addition, the amount of active radiation is always greater than the minimum required for Earth-like photosynthesis. In other words, cave entrances could house both humans and their source of plant food. However, it is not clear whether ionizing radiation – the type of electromagnetic radiation associated with cancer – is blocked in the same way as UV radiation.

“Ionizing radiation does not exhibit exactly the same behavior as UV rays,” said Viúdez-Moreiras. Recount New Scientist. “However, ionizing radiation is also expected to be strongly attenuated in pit craters and cave dormers.”

High-resolution surface imaging data recorded over the past two decades by instruments such as the Mars Reconnaissance Orbiter (CTX) pop-up camera system, as well as the Mars Odyssey Thermal Emission Imaging System (THEMIS) , suggest that the Tharsis bulge may be the best region for candidate caverns on Mars. Over 1000 suitable caves have been identified in this region, which also contains three huge shield volcanoes, Arsia Mons, Pavonis Mons and Ascraeus Mons.

The city of Tharsis sounds like a brilliant name for the first human settlement on Mars. Remember the name.