Why do I care about radiation?
While the Christopher Tyson books are not intended to be on the same level of realism as, for example, ‘The Martian’, I do want to cover the pitfalls and realities of space travel, albeit of the more fantastical kind. The dangers of radiation in space and how it is overcome will be dealt with (though perhaps not in book one, there’s only so much I can fit in!), and as a result, a recent article on the BBC grabbed my attention (click here).
This is especially interesting in relation to future space travel and the colonisation of other worlds. One of the most troublesome aspects of travel in deep space is radiation. In science fiction there tend to be a small number of solutions. In more fantastical science fiction it is usually covered by a brief mention of shielding (either hull-plating or some form of electro-magnetic field), and in more ‘realistic’ sci-fi the crew of a ship will hide in an area shielded by the ship’s water supplies or similar (water is one of the more effective radiation shields we would have at our disposal).
All too often, however, the matter of radiation is simply forgotten or ignored in science fiction, so I’m going to talk a little about the dangers of radiation in space. If you want to jump straight to the Water Bears, just scroll down!
The dangers of radiation in space
The Earth itself is protected primarily by two things, it’s magnetic field (magnetosphere) and its atmosphere. The magnetic field deflects most of the harmful radiation, and most of what remains is stopped by the atmosphere which, on average over its depth, equates to a barrier of metal about 3ft thick. (click here for more information)
Around Earth, the primary danger is the Van Allen Belt. This has two main belts, the inner one being the worst. These can easily damage the electronics in satellites, (especially modern satellites), and when the Apollo missions went to the moon, they had to avoid the inner belt and pass through the fringes of the outer belt as quickly as possible.
Once you’re beyond the influence of the planet you have radiation from the sun and the rest of the galaxy in the form of sub-atomic particles that will rip through your DNA or damage the information encoded within it (so cell reproduction contains errors, and you effectively get the beginnings of cancer). Radiation can be ionizing (high energy) and non-ionising (low energy). Although both can be damaging, non-ionising is the least dangerous (you can include visible light, ultra violet light, radio waves in this list). Ionising radiation, however, is the most dangerous. This is where you get your x-rays, gamma rays and galactic cosmic radiation. Ionising radiation has the ability to strip electrons from individual atoms, thus causing the damage to our DNA that I mentioned above.
Solar flares are especially dangerous, because they release large quantities of harmful radiation, especially x-rays and gamma rays. Then there are cosmic rays, accelerated to near the speed of light and thought to also have a degrading effect on the brain, similar to Alzheimers over prolonged periods (The origins of cosmic rays are not precisely known, but one source is thought to be the after-effects of supernovae from massive stars).
Water Bears and Space Travel
So why am I waffling on about the dangers of radiation in space? Well, that would be because of Water Bears, of course! The proper name for a ‘Water Bear’ is a Tardigrade, a water-dwelling eight-legged microscopic animal, first discovered by German zoologist Johann August Ephraim Goeze in 1773.
Tardigrades are known to be the hardiest form of animal life on the planet. Such creatures are known as ‘extremophiles’ and in the case of Tardigrades, are capable of withstanding boiling and freezing temperatures, as well as… you guessed it! Radiation.
Scientists have only recently discovered how they survive extreme radiation (Click here for more information). Originally, they were thought to repair the damage to their DNA somehow, but what they learned is that the Tardigrades have a protein that attaches to its DNA and protects it from damage in the first place (they have called this Dsup, short for Damage Suppressor).
They have since attached this Dsup gene to human cells and found that they suffer far less damage to their DNA when exposed to x-rays. Already, they’re thinking about how this could be used to protect organisms on the surface of Mars (which has a weak magnetic field and thin atmosphere to protect from radiation), perhaps even helping any plan to terraform the surface.
From my perspective, this begs the question… Could spacefaring humans have this added to their genetic make-up, and would it enable them to survive more safely in space, certainly for longer periods? We all suffer the effects of radiation, as the Earth’s magnetic field and atmosphere don’t completely shield us (not to mention background radiation from the planet itself). So while something like the Dsup gene wouldn’t protect us one hundred percent, it might, in combination with other conventional methods, provide a realistic way to survive the dangers of lethal radiation in deep space. Could we even line the interiors of our spaceships with layers of wet moss that contain thriving colonies of Water Bears?
It would be quite amusing, if one of the planet’s smallest creatures provided the answer to safely travelling to other worlds in our solar system and beyond…
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