When you bring a juicy piece of meat home, you immediately put it in the freezer. You do that because bacteria doesn‘t like cold. Right? That is pretty much the reason why for a long time scientists thought polar ice and snow was considered to be a sterile environment. However, now scientists have directly observed living bacteria in polar ice and snow.
This unexpected discovery will have huge implications on science. First of all, just by researching tiny compressed gas bubbles in snow scientists will be able to look back in Earth’s history. Secondly, this alter our perception on which planets in the universe can host life. The process of snow compressing into ice can last decades. Tiny gas bubbles get trapped in the mixture and compress together with snow. Respiration of bacteria increases CO2 levels in these tiny pockets of air. Not only this is very interesting, but also alters the way scientists predict climate change.
The ongoing debate is how do you gauge climate change-inducing CO2 levels without a proper base. That base has been these pockets of air in the polar ice. However, maybe comparison wasn’t so accurate if living bacteria was increasing levels of CO2 in that ice? Maybe our CO2 increase is actually even bigger than we thought?
Cutting edge technology allows measuring these tiny differences in gas concentrations very precisely. Scientists conducted some laboratory testing with natural snow and one that was sterilized by UV light. They noticed the difference in concentration of some gases was significant enough to predict presence of tome metabolically active marine bacteria. Scientists were working in Artic and Antarctic regions, being very careful to take sample of snow away from local wildlife and not to pollute them themselves.
There are many planets that scientists deemed uninhabitable because of their low temperature. We are not even considering looking for extra-terrestrial life there. However, this new discovery shows that microbial life can be found in planets where water is found as ice. Dr Kelly Redeker, lead author of the research, said: “We know that bacteria have the potential to remain viable and metabolically active at low temperatures for hundreds to thousands of years. The next step is to look further down to see if we can observe active bacteria deep in the ice caps”.
This study also reveals how much we still don’t know about our own planet. Places we see as lifeless are actually very interesting if you look close enough. It will be interesting to see how deep scentists can find these traces of microbial life in polar regions.
Source: University of York