Based on data from Curiosity’s Radiation Assessment Detector, or RAD, researchers are finding that using natural materials such as the rock and sediment on Mars could offer some protection from this ever-present space radiation.
Far more intense radiation sporadically comes from the Sun in the form of solar storms that throw massive arcs of ionised gas into interplanetary space.
“The observations from RAD are key to developing the ability to predict and measure space weather, the Sun’s influence on Earth and other solar system bodies,” added Jim Spann, space weather lead for NASA’s Heliophysics Division.
“Cosmic rays, solar radiation, solar storms — they are all components of space weather, and RAD is effectively a space weather outpost on the surface of Mars,” said Don Hassler of the Southwest Research Institute, principal investigator of the RAD instrument, in a statement.
Unlike Earth, Mars doesn’t have a magnetic field to shield it from the high-energy particles whizzing around in space. That radiation can wreak havoc on human health, and it can seriously compromise the life support systems that Mars astronauts will depend on, as well.
Most of the radiation measured by RAD comes from galactic cosmic rays — particles cast out by exploding stars and sent pinballing throughout the universe. This forms a carpet of “background radiation” that can pose health risks for humans.
As NASA plans for eventual human journeys to Mars, RAD serves as an outpost and part of the Heliophysics System Observatory — a fleet of 27 missions that investigates the Sun and its influence on space — whose research supports our understanding of and exploration of space, Spann said.
RAD has measured the impact of more than a dozen solar storms to date (five while travelling to Mars in 2012), although these past nine years have marked an especially weak period of solar activity.
Scientists are just now starting to see activity pick up as the Sun comes out of its slumber and becomes more active. In fact, RAD observed evidence of the first X-class flare of the new solar cycle on October 28, 2021. X-class flares are the most intense category of solar flares, the largest of which can lead to power outages and communications blackouts on Earth. RAD’s findings will feed into a much larger body of data being compiled for future crewed missions. In fact, NASA even equipped Curiosity’s counterpart, the Perseverance rover, with samples of spacesuit materials to assess how they hold up to radiation over time.