Question: How can solar particles pass through the walls of space stations, and how do the affect the astronaut's cells?

Jaclyn Bell answered on 20 Mar 2015:

Solar energetic particles, like those that come from solar flares or coronal mass ejections can be very dangerous to astronauts and it is one of the problems with human interplanetary travel – this is a massive problem we will face when trying to send a team of astronauts to Mars – how will we protect them from the radiation over a long period of time? Astronauts are bombarded by particles, which they are (mostly) normally shielded from on Earth, and so they are being exposed to radiation. The international space station has aluminium walls which are believed to produce a net reduction in radiation exposure, and there is a team back on Earth that monitor each astronaut and the amount of radiation they are being exposed to. NASA scientists monitor and check space weather conditions in order to protect astronauts and hardware in orbit from harmful radiation.

I thought that high energy solar particles in space would affect the astronauts cells the same as too much UV(B) exposure on Earth – cells would mutate and become cancerous/tumours. However I just read on Wiki that in fact because it is high energy radiation in space the radiation would just kill your cells without them becoming tumours or cancerous first… whereas low energy radiation (like here on Earth) causes tumours to form or cells to mutate. This makes sense when we think about is as we fight cancerous cells by firing high-energy radiation at them – which kills them – and so this is what happens up in space if you stay up there too long without shielding. But scientists back on the ground monitor this and so astronauts are never up there long enough to suffer long term health effects 🙂