Environmental zones and driving bans are the result of air pollution in many countries on planet Earth. But scientists also use indicators like nitrogen dioxide for other purposes - for example, to explore space and find evidence of extraterrestrial life.
Nitrogen dioxide and fine dust from traffic and industry change the composition of the air on Earth. NASA researchers use the concept of air pollution to find possible civilisations in space. According to the research team around Ravi Kopparapu, life could soon be found up to 30 light years away with space telescopes.
According to the researchers, nitric oxide is particularly suitable because it is a so-called technosignature, or technomarker, which is produced as a waste product during various combustion processes. Unlike biomarkers, such as organic compounds, it points to more advanced civilisations that use technologies similar to ours. However, the gas is also produced naturally. After measuring nitrogen oxide in the vastness of space, it would therefore also be necessary to model how much of the gas is produced there naturally.
According to the research, it can be assumed that we are easily recognisable in space due to our air pollution. So if there are civilisations that are so advanced that they produce nitrogen oxide through combustion processes, it is also conceivable that these civilisations are searching for life on other planets in a similar way to us.
With the amounts of nitrogen oxide that we blow into our atmosphere every day, it would then probably only be a matter of time before they discover us. Perhaps another reason to reduce air pollution and switch to greener technologies. Then environmental zones and diesel driving bans would probably be the lesser of two evils for some...