If there is one thing the human race has learned in 2020, it's that global pandemics are very real. For most people it is a first for the threat of pathogens but for NASA, the issue has been ever-present for a long time. Ever since the Apollo missions, there has always been the risk we will take something into space or bring something back.
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NASA takes this threat so seriously it appointed a planetary protection officer to oversee protocols surrounding interplanetary contamination.
There are two types of interplanetary contamination: forward and backwards.
Forward contamination means taking any life from Earth and potentially seeding it on another planet. Unfortunately, it is likely we have already contaminated Mars, the moon and any asteroids we have landed on. It is near impossible to completely rid anything of life, including space-bound objects.
As it turns out, some Earth microbes are pretty tough.
Extremophiles, meaning "lover of extremes", are organisms that can survive all manner of environments we would consider too extreme for life. Including very high and low temperatures, extreme pressure, acidity, radiation and much more. An example is Belgica antarctica, a wingless insect that can survive the sub-zero temperatures of the icy continent. Living bacteria has even been found on the outside of the International Space Station, seemingly surviving in space.
To minimise this, anything that is space-bound is constructed in a clean room. Here, air is filtered at a much higher rate than the conventional lab. Scientists must also wear full-covering suits when working. Mount Stromlo Observatory in Canberra has its very own clean room for the construction of satellites.
However, most scientists will admit these clean rooms are more for keeping dust out of sensitive equipment than stopping microbes. We may even be creating tougher microbes by forcing them to evolve to survive sterilisation procedures such as using gas to break down biological structures.
But ultimately, forward contamination is a known entity. We hope these microbes either die or we are able to recognise them when the time comes. If we want to explore other planets, it's a risk we have to accept.
As we are edging ever closer to bringing samples back from Mars and as we are faced with the absolute havoc an unknown microbe can ravage on society, scientists turn their thoughts to back contamination and preventing Earth being exposed to life from the depths of outer space.
Just this month NASA has released new directives for the return of Martian samples. Rather than detailing any specific processes, the directive makes a commitment to researching ways to minimise contamination. Suggestions include creating a "Mars sample return receiving facility", an extreme clean room, away from populated areas that would be triple-walled and where all handling of samples would be done by robots. An unofficial test run will occur this December when a completely sealed sample return capsule will drop into the South Australian outback. This will avoid contamination from the larger Japanese space probe-Hayabusa 2- which was directly exposed to the surface of the asteroid Ryugu.
What do we take from this? Life is everywhere and we will always be trying to rid it from places we do not want it to be. We should just be grateful the one plaguing us right now can be killed with soap.
- Abby Hodges is a former outreach officer at Mount Stromlo Observatory, ANU and currently works for the Science and Engineering Challenge at the University of Newcastle, but maintains an interest in astrobiology.
