Earth-Grown Bacteria

By on 3:26 PM

Transitioning from an earth-based society to a space-based society presents thousands of challenges. The isolation, radiation and detrimental effects of reduced gravity are usually some of the first issues considered – and rightfully so. However, many astrobiologists are concerned with a problem we've yet to solve on earth: invasive species.

The introduction of invasive species can wreck absolute and unpredictable havoc upon an entire ecosystem. You don't have to look very hard to see numerous examples. Zebra Mussels, Water Comb Jellies, Feral Goats, and Wild Boars have all had absolutely massive effects on environments in the past 50 years.

If we as humans have such a huge problem keeping these animals from spreading to other areas of the earth, imagine how difficult it is to keep micro-organisms like bacteria from spreading across other planets.


It turns out that bacteria are pretty much everywhere and, thus, really difficult to completely remove. Not only that but there are millions of different types of bacteria, some of them are so resilient they fall into completely different categories of life.. For example, scientists have discovered what have been dubbed extremophiles, ridiculously resilient organisms. Some of these organisms – usually micro-organisms – have a level of resilience that would generally be considered absurd.

In Japan, scientists have tested the ability of some fairly common bacteria to survive under additional gravity. How high could they survive?

Over 400,000 times earth's gravity. That's not a typo. That's a four followed by five zeros.

For comparison, unaided humans will pass out at around 4 times earth's gravity. Strangely, gravitational forces in the 400,000g range are only found in a couple of places in the universe, mainly very large stars and supernova shock-waves.

In other words, it's quite likely that there are numerous types of bacteria capable of surviving for short periods of time in space and probably capable of sustaining life on planets we would deem inhospitable.

And we've already messed up.

Following a breach of proper procedure the Surveyor 3 moon probe was found to have Streptococcus mitis – a common bacteria – on the camera lens alive and well, two years after the craft had last been on earth. While it’s entirely possible that the bacteria was transferred to the lens during the retrieval process, it nevertheless demonstrates our own failure to adequately prevent the transmission of microbial life forms.

So why is this bad?

The idea of alien life forms hitching a ride on human spacecraft to get to earth is called backwards contamination, and has been explored in numerous books, movies, and essays. This obviously has the potential to be a serious problem – but seeing as we've yet to find any sign of life on other planets, this isn't really immediately pertinent.

More important – in the short term at least – is forwards contamination, or earth-based bacteria moving to other planets. There are two main harms that can arise from this. First is the possibility of a false positive, or terrestrial life being brought to another planet then later “found” and deemed alien life. While the odds of this happening are admittedly small (considering that alien life is unlikely to have evolved into the same life-forms found on earth), as the time between seeding a planet and “finding” the life increases, the odds of a false positive increase due to the life forms having more time to adapt to their environment and diverge from their terrestrial counterparts.

The other, more serious possibility from forward contamination is the devastation of an alien planet or ecosystem. Even if a planet has no living ecosystem, by contaminating the planet with terrestrial life, study of the planet as it was before contamination becomes much more difficult. For example, is some probe traveling to Venus was contaminated with a heat resistant bacteria, capable of converting carbon dioxide into oxygen, the Venus of 100 years would look very different from the Venus of now and destroy scientists chances to study the affects of a run-away greenhouse effect as well as numerous atmospheric studies.

What can we do?

Assuming we want actual people to visit planets, there isn't a whole lot we can do other than be careful. Humans have an absurd amount of bacteria in and on us, many of which are necessary for our health and life so it’s not really feasible to remove them. Having said that, there are some basic precautions that can be instituted.

Using redundant cleaning stations is a common idea. Another popular idea is some sort of rapidly altering sterilization system, the idea being that even the most hardy of bacteria are generally only resistant to a few different types of sterilization techniques. With this, after some astronauts don their suits, they're bombarded by a plethora of different extreme phenomena including severe cold, intense heat, high radiation levels, and a highly acidic or basic compound, all in quick succession.

With the astronaut protected by the suit, anything outside of the suit would be nearly completely destroyed due to the rapid and intense changes in the surrounding environment. Unfortunately, this process would require some sort of suit that could completely protect the astronaut from each of these phenomena, something that is currently not feasible.

Sterilizing probes and other unmanned vehicles is quite a bit easier, though still remarkably difficult. Even though there isn't a human in need of protection, some pieces of equipment can be surprisingly fragile, making the idea of a rapidly changing environment still a challenge.

It's also important to remember that there are naturally certain times we need to be more careful about sterilization than others. For example, the Committee on Space Research puts far more stringent requirements on sterilization when sending something to Europa than it does when sending a probe to Mercury.

Luckily, there is a general consensus among the scientific community on the importance of proper sterilization techniques and, hopefully, this will culminate in us not destroying the ecosystem of the first planet we find alien life on.

Want to spread the word on not spreading bacteria around the universe? Please be sure to recommend this post on StumbleUpon – all it takes is a click!

Rusty is the co-founder of How To Survive Alien Invasion Novels, and gets up to all kinds of shenanigans planning for any and all kinds of apocalypse when he's not busy reading, writing, or yo-yoing. Keep up with him and Rachel on Facebook and Twitter to get cool, space related news or click here to read more of his thoughts on the terror of alien invasion novels.

About Syed Faizan Ali

Faizan is a 17 year old young guy who is blessed with the art of Blogging,He love to Blog day in and day out,He is a Website Designer and a Certified Graphics Designer.


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