Mars lacks a magnetic shield and a thick atmosphere like Earth, making it vulnerable to radiation attacks on its surface. However, recent findings by scientists have identified certain areas on Mars that may be able to “dodge” radiation.
For humans, radiation poses a deadly threat. How can explorers cope with this? They will need a shelter, and they will either have to bring a special tool or somehow construct it on Mars. Alternatively, they could utilize natural features as part of their protective measures.
A new study utilizing data from the Mars Science Laboratory (MSL) Curiosity has uncovered several potential shelter locations from radiation.
When MSL Curiosity landed on the surface of Mars in 2012, it carried with it a device known as the Radiation Assessment Detector (RAD).
RAD data shows that near the Murray Buttes region, radiation levels decrease by about 5%.
RAD prepares for future human visits to Mars. It detects and measures harmful radiation on Mars emitted from the Sun and other sources. It can also assess the danger that radiation poses to any microbial life that may exist on Mars. RAD is the size of a toaster and is discreetly located on the upper surface of Curiosity.
One of the regions studied by MSL with RAD is the Murray Buttes region. The Murray Buttes region is situated on the lower slopes of Mount Sharp within Gale Crater.
Curiosity primarily investigates geology, particularly the characteristics of sandstone and a type of layering known as “cross-bedding.” In addition, RAD continues to collect data, which indicates a reduction in surface radiation.
RAD data shows that near the Murray Buttes region, radiation levels decrease by about 5%. The research team also constructed a sky view map, showing that 19% of the sky is obscured when the rover is next to the Murray Buttes region. This data is very important.
While driving through the Murray Buttes area, Curiosity was not obstructed in its view of the sky due to the terrain features. Therefore, the team built a panoramic sky view from an average taken in the preceding months to compare with the collected data.
Scientists also discovered that similar surface features that could protect against direct radiation could also enhance reflected radiation. RAD indicated that the Murray Buttes region could produce an increase in secondary reflected radiation. This is one of the complexities in understanding radiation on Mars. Radiation on the surface of Mars is not consistent but fluctuates.
The orbit of Mars changes its distance from the Sun, which also affects surface radiation. Lower elevations experience less radiation compared to higher elevations. Radiation is not a uniform phenomenon: it includes protons, alpha particles, ions of various elements, neutrons, and gamma rays.
This study helps paint a broader picture of the radiation environment on Mars. There has been considerable thought put into utilizing in-situ resources on the Red Planet. Shelter is a primary need for explorers on Mars, and if advantages can be gained by using existing terrain features for protection, then those features will be suitable for future missions.
There has been much discussion about establishing bases in lava tubes, where humans would be protected by meters of regolith on Mars. However, astronauts cannot spend all their time there. They will have to be exposed to radiation.
Any mission to Mars involving human participation will require multiple layers of backup. In any emergency situation, it is crucial to keep the radiation exposure of astronauts as low as possible.
