Unless youre talking to the likes of Peter Parker or Bruce Banner, being exposed to radiation is a bad time. In general, it weakens or breaks our DNA causing cell mutations leading to a plethora of malignant cancers and disease. Sadly, not possible spidey sense or super powers. Yet, for various reasons like modern medicine, technology such as air travel, or even certain food stuffs, radiation is a huge part of our human existence. Putting some numbers on this, the background radiation that most normal folk like you or I can expect to be exposed to is around 2.4 mSv a year. Comparatively a single CT scan is around 3 times that much, yet with these amounts we can thankfully still be happy and healthy. But how much is say, a return interplanetary transit to and from the Martian surface? A DNA crunching 780 odd mSv or radiation essentially 325 years worth of normal radiation dosage in a fraction of the time. Why is this bad news? Whats scary is that without the warm embrace of Earths atmosphere and magnetosphere that keeps us sheltered, this radiation dosage is at very fatal levels. In fact, this dosage is so large that its around 6-8 times the safe NASA approved limits of what a 35 year old male can be exposed to. To make matters worse, flares from the Sun contain huge amounts of radiation and are largely unpredictable, putting the astronauts dosage largely to chance. Radiation is such a huge hurdle with a mission to Mars that some research expects hundreds of tonnes of shielding material alone may be needed to keep the astronauts unharmed. Lead vests anyone?
