As far as we are aware, no organism has ever lived or died on our red neighbour, Mars. Perhaps evidence will one day emerge of fossilised bacteria hidden within Martian rock. There is indisputable proof that water once flowed freely on the surface after all, which is one prerequisite for life as we currently understand it. Some scientists have even suggested life could exist today in underground, water-filled caverns, though I’m not sure how likely this is. Whatever the truth, nobody has doubted that Mars’ oxygen-less, atmosphere-limited, distant surface would be an easy place to live, but this hasn’t deterred humanity’s persistent dream of one day walking on the red planet.
The Curiosity Rover’s latest discovery, on the other hand, might do just that. Apparently the level of radiation potential astronauts would endure in both traveling and settling on Mars are far beyond what is considered safe for a human to experience. Here are some figures, taken from the BBC (measure in millisievert, the unit of equivalent radiation dose):
- Annual average: 2.7mSv
- Whole body CT Scan: 10mSv
- 6 months on the International Space Station: 100mSv
- Traveling to and from Mars (excluding time spent on planet): 660mSv
For the average human in a developed country exposed to 2.7mSv a year (so perhaps just over 200mSv in a lifetime), the chances of developing a cancer are around 1 in 4. If I understand this correctly, this makes the chances of developing a cancer after traveling to Mars far greater than ought to be acceptable.
This, understandably, poses huge problems for the future of space exploration. It’s incredible that such a haven for life could ever develop on the Earth considering how many dangers exist to us outside of the planet. While I think some scientists are still optimistic, I find these figures very depressing. They serve to remind me that the Earth is not a cradle, but a prison. We are trapped here for each of our tiny lives until the prison walls break down and then even here won’t be inhabitable – once the solar flares beam down, or the surface becomes irradiated by ultra-violet light, or a stray piece of rock slams into us, or…
Mars is a world of death and Earth a world of life. But Earth is defying the norm of the Universe – how long before it joins Mars? It’s as if the Universe were designed with the strict intention of making life impossible.