Astronauts travelling to Mars face a wide manner of dangers but the deadliest of them all could be space radiation. Every single second charged particles travelling at near the speed of light hurl through the vacuum of space. On Earth, the planet’s atmosphere and magnetic field protect us from harmful space radiation punching through our bodies. In space, however, where radiation levels can be 700 times higher than on Earth, there is nothing to protect astronauts.
On the International Space Station (ISS), for instance, astronauts report seeing flashes of light when closing their eyes – particles passing through their heads at incredible seeds.
Astronauts on the ISS are exposed to about 200 times more radiation than an aeroplane pilot.
And the bad news for future Mars-bound missions is a single trip to the Red Planet takes between seven and eight months.
Such prolonged exposure to space radiation can be lethal for anyone hoping to settle Mars in the near future.
Marco Durante, a physicist who studies cosmic radiation on Earth, said: “One day in space is equivalent to the radiation received on Earth for a whole year.”
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The threat of cosmic radiation is typically associated with an increased likelihood of cancer.
The damage caused by space radiation targets the brain, the heart and the central nervous system.
In the long run, the European Space Agency (ESA) warned this “sets the stage” for degenerative diseases.
According to ESA, a higher percentage of early-onset cataracts have been reported in astronauts.
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When ISS Commander Scott Kelly returned to Earth after spending a year in orbit, NASA studied his body for signs of damage and compared the results to his twin brother Mark Kelly.
NASA’s so-called Twins Study found Commander Kelly suffered DNA damage as a result of his exposure to cosmic radiation.
And unfortunately, there are still many unknowns about the exact effects of space radiation on the human body.
Dr Durante said: “The real problem is the large uncertainty surrounding the risks.
“We don’t understand space radiation very well and the long-lasting effects are unknown.”
Measurements taken by the ExoMars Trace Gas Orbiter show a sixth-month trip to the Red Planet would result in 60 percent of the total radiation limit meant for an astronaut’s entire career.
So, what does this mean for the future of human Mars exploration?
Dr Durante said: “As it stands today, we can’t go to Mars due to radiation.
“It would be impossible to meet acceptable dose limits.”
