Here's some bum news for anyone harboring romantic notions about outer space: even if a manned trip to Mars is possible, it'll kind of melt your brain in the process. Researchers examining the effects of radiation on brain degeneration have uncovered what they believe is a link between cosmic rays and accelerated Alzheimer's disease. They found that "galactic cosmic radiation poses a significant threat to future astronauts."
Okay, but what now?
Space is filled with radiation that can harm people. While Earth's magnetic field generally protects the planet, once astronauts venture beyond low-Earth orbit, they are constantly bombarded by a shower of dangerous particles known as cosmic rays. The longer an astronaut is in deep space, the greater the risk, which is especially of concern given NASA plans for manned missions to an asteroid in 2025 and to Mars by about 2035 - the round trip to the Red Planet alone could take at least two years.
O'Banion and his colleaguesinvestigated a specific kind of space radiation known as high-mass, high-charged (or HZE) particles. These particles zip through space at very high speeds, likely the result of exploding stars and other deep-space catastrophes from elsewhere in the galaxy. Unlike cosmic rays consisting just of hydrogen nuclei, which solar flares generate, the mass and speed of HZE particles allow them to punch through solid objects such as a spacecraft, or any astronauts inside.
"Because iron particles pack a bigger wallop, it is extremely difficult from an engineering perspective to effectively shield against them," O'Banion said. "One would have to essentially wrap a spacecraft in a 6-foot block of lead or concrete."
Ugh. Stressful. Space is so stressful! Also, astronauts, YOU ARE SO BRAVE AND I CANNOT BELIEVE YOU JUST GO OUT THERE AND FLY AROUND LIKE THAT. Watch your brains, okay?
Astronaut ice cream, as far as I can tell, is still safe. So there's that.