NASA’s Curiosity Rover Determines Martian Radiation
by Tom Edathikunnel
NASA’s Martian probe Curiosity has recently made detailed measurements of the absorbed dose and dose equivalent of cosmic rays and solar energy particles on the surface of Mars. Using the Radiation Assessment Detector, or RAD, aboard the rover, scientists now have a more detailed glimpse into the atmospheric and cosmic climate of Mars.
First published in November’s issue of Science, these measurements provide valuable assessment information for future manned missions to Mars. By monitoring the radiation and effects of solar storms on the Martian surface, scientists can determine if conditions are pragmatic for a human mission.
“Our measurements also tie into Curiosity’s investigations about habitability. The radiation sources that are of a concern for human health also affect microbial survival as well as the preservation of organic chemicals.” Stated Dr. Don Hasslar of Southwest Research Institute.
Findings show two forms of potentially harmful radiation. One is a chronic low dose of galactic cosmic rays and the other is short-term exposure of solar energetic particles, which are produced from solar flares.
Radiation on the Martian surface is much harsher than on Earth. Mars lacks a global magnetic field, which acts as a natural shield against solar radiation. Additionally the atmosphere on Mars is much thinner, providing little shielding to the surface.
The radioactive particles can penetrate Martian soil and mix with the regolith, the powdery rock on the surface, which is the main contributor to the complex radiation environment on the Martian surface.
Long-term exposure to radiation can prove harmful and even deadly. A 500-day mission on the surface would bring the total radiation exposure to around 1 Sieverts. Exposure to a dose of 1Sv is associated with a five percent increase in fatal cancer risk.
These findings bring new questions about radiation exposure in deep space as well as possible remedies and technologies to curb its effects. Curiosity’s discoveries yield new light on the possibility of Martian life and conditions. With findings of an ancient fresh water lake earlier this month, the possibility of solid evidence of life and a manned mission to Mars seem to be just as indeterminate and exciting as ever.