Are space pollutants just garbage?
We know that exoplanets are ubiquitous in the Milky Way, but questioning extraterrestrial life and culture is just speculation. To this day, astronomers still haven't found any relevant evidence, so they're still excited about how to find it. The new study proposes a unique approach to looking for contaminants.
The paper was published in the Astrophysical Journal and is available in preprints online. In this paper, the research team explored how to discover alien civilizations using nitrogen dioxide (NO2), a gas produced by a combustion process that is visible when observing the atmospheres of distant planets with the New Age Space Telescope.
"Most of the nitrogen dioxide (NO2) on Earth is emitted by human activities, such as car exhaust and the combustion process of fossil fuel power plants." Lead author of nasa's Goddard Space Flight Center, Ravi M. Ravi Kopparapu noted in a statement that "in the lower atmosphere (about 10-15 km or about 6.2-9.3 miles), human activities emit much more nitrogen dioxide (NO2) than unmanned planets emit." Thus, the discovery of nitrogen dioxide (NO2) on a habitable planet basically indicates the existence of an industrial civilization. ”
In the atmospheres of these exoplanets, astronomers are looking for signs of life, all of which are biomarkers. But now, they are also beginning to look for some "technical signs", that is, molecules in the air of industrial civilization in distant planets.
Other studies have identified chlorofluorocarbons (CFCs) as a possible technical marker. Chlorofluorocarbons are industrial products that were once widely used as refrigerants, but were gradually discontinued due to their destructive effects on the ozone layer. Co-author Jacob from the Blue Marble Science Institute in Seattle, Washington. Huck. Jacob Haqq-Misra adds, "Chlorofluorocarbons (CFCs) are also a very strong greenhouse gas, and by heating up the atmosphere, it can make planets like Mars as habitable as Earth." As far as we know, it is never possible for organisms to produce chlorofluorocarbons (CFCs), so it is more obvious as a technical marker than nitrogen dioxide (NO2). However, chlorofluorocarbons (CFCs) are very unique industrial chemicals that may be rare elsewhere. In contrast, nitrogen dioxide (NO2) is a by-product of a very common combustion process. ”
Discovering nitrogen dioxide (NO2) does not mean "found, we found extraterrestrial life." The gas can also be generated naturally, so astronomers also need to estimate whether the signals they get are enough to indicate that the nitrogen dioxide comes from a technological society.
"About 76 percent of nitrogen dioxide (NO2) on Earth originates from industrial activity," said one of the paper's co-authors, Gada of the National Aeronautics and Space Administration's Goddard Space Research Institute. Giada Arney explains, "If nitrogen dioxide (NO2) is observed on another planet, we would have to run some models to estimate the maximum nitrogen dioxide emissions on an industrial-free planet. If we observe higher emissions of nitrogen dioxide (NO2) than the model gives, the remaining portion may be the result of industrial activity. However, in the process of searching for extraterrestrial life beyond the Earth, there will inevitably be some false positives, which requires us to be sure to distinguish between true positives and false positives in our future work. ”
Clouds and aerosols can also produce false positives. Next, the team wants to make a better model of the atmosphere so that we have a more realistic channel to understand what the nitrogen dioxide signal looks like.
Related knowledge
Extraterrestrial life, also known as extraterrestrial life, refers to life that exists outside the Earth. The concept ranges from simple bacteria to highly intelligent "aliens." The discipline of studying and testing conjectures about extraterrestrial life is called extraterrestrial biology or astrobiology [Note 1]. Since the mid-20th century, humans have been using methods that include detecting radio waves beyond Earth and observing potentially habitable planets with telescopes, but there is no definitive evidence of extraterrestrial life so far. Some believe that the chances of alien detection are slim,[1][2] while others believe that extraterrestrial life is almost certain.
Western scientist Charles Lineweaver and others proposed the "Milky Way Habitable Zone" ( ) . According to their calculations, this "belt of life" is about 23,000-30,000 light-years from the center of the Milky Way, roughly equivalent to 7% of the Milky Way's radius, and contains less than 5% of the 5 billion potentially life-giving stars in the Milky Way.
Many of the works have aroused public interest in the possibilities of extraterrestrial life. There are those who encourage radical access to extraterrestrial intelligent life, claiming that there may be intelligent life within the galaxy and reaching a communicative level, and the idea that intelligent life still acts according to the laws of the dark forest is ridiculous.
According to a declassified NSA study, at least 100 million planets in the Galaxy can have the conditions to nurture life, including suitable temperatures and chemical conditions.
BY: Dr Alfredo Carpineti
FY: Brite SUN
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