Mars radiation levels tolerable to humans
The Mars rover Curiosity has revealed that the radiation levels on Mars are not, according to initial measurements, lethal to humans.
“Absolutely, astronauts can live in this environment,” said Don Hassler, Principal Investigator for the rover’s Radiation Assessment Detector, at a press conference Thursday.
But don’t plan on booking a trip yet. You still have to add up the total radiation that you would soak up during the eight to nine months that it takes to get to Mars, and the eight to nine months back, not to mention the actual time on the surface. An astronaut would need to spend at least six months on the surface, and stay within the career limits for radiation.
Characterizing the radiation on the surface of another planet has never been done before now, Hassler said.
Over time, researchers will get all of those radiation numbers to create a better assessment of exactly how much radiation a person would experience during a Martian journey, Hassler said.
It appears that the radiation measurements are a factor of 2 less than during the trip, which isn’t surprising, given that the planet’s atmosphere offers some protection, Hassler said. When a solar particle event does occur, that will tell researchers more about spikes in radiation that astronauts might experience.
It’s important to understand how much radiation is hitting the planet in order to get more insight into Mars’ habitability – past, present and future.
The rover has also recently measured the variations in the atmospheric pressure on the planet. Scientists found that there are daily variations in atmospheric pressure.
“We’re finding that the Mars atmosphere is acting as a shield for the radiation on the surface,” Hassler said. “And as the atmosphere gets thicker, that provides more a shield, and therefore we see more of a dip in our radiation dose.”
Of course, Mars does not shield its surface from radiation the way that Earth does. Mars appears to have lost its global magnetic field 3.5 billion years ago, whereas Earth still has one. And the atmosphere of Mars is about 1% the thickness of atmosphere on Earth.
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Image credit: NASA/JPL/CalTech