[Epoch Times February 26, 2021](The Epoch Times reporter Di Rui compiled a report) Before, scientists generally used to detectExoplanetThe combination of oxygen and methane in the atmosphere as a searchAlien lifeBecause these components are related to the life activities of organisms.
A new study by NASA proposes that alien technological civilizations are likely to cause pollution similar to human industrial activities in their atmospheric environment, perhaps through detectionExoplanetWhether there are pollutants in the atmosphere, determine whether there is technological civilization on it.
There are many pollutants emitted into the atmosphere by human industrial activities, and nitrogen dioxide gas is one of them. This study found that the nitrogen dioxide gas in the atmosphere has a strong ability to absorb visible light of a specific color. The light reflected from the atmosphere of an exoplanet can analyze the nitrogen dioxide in the atmosphere of this planet.
This study suggests that the nitrogen dioxide content in the atmosphere of exoplanets can be used as a potential indicator for searching for alien technological civilization. Nitrogen dioxide is one of the products of petroleum combustion, but non-industrial activities such as some biological activities, lightning and volcanic eruptions also produce some.
NASA researcher Ravi Kopparapu said: “On Earth, most of the carbon dioxide gas is the product of human activities-car exhaust and emissions from petroleum-fueled power plants. In the low-altitude atmosphere (10 ~15 kilometers), the nitrogen dioxide content produced by human activities accounts for the vast majority. Therefore, the nitrogen dioxide content on a habitable planet can be used as a potential indicator for judging whether there is an industrial civilization on it.”
So far, scientists have discovered more than 4,000 exoplanets, and believe that some of them may have life on them, and there may even be life with technological civilization. However, because they are very far away from the earth, the method of sending probes to explore is not feasible, so scientists thought of using the powerful telescopes now to spy and speculate on the conditions inside the world.
According to NASA, this is the first study that recommends using nitrogen dioxide as an indicator of technological civilization for exploring exoplanets.
Research and establish a model to analyze the range of technological civilization of exoplanets that can be detected at the furthest distance using existing telescope technology. Their model shows that if a planet like the Earth orbits the sun, if the civilization on it produces a considerable amount of nitrogen dioxide as it is on the earth, using the most advanced telescope that NASA will launch, the farthest can be from 30 light years away. Detected from 400 hours of observation data.
A light-year is already a long distance, about 9.5 trillion kilometers. The closest star to our sun is 4 light-years away, and the width of our Milky Way is about 100,000 light-years.
The study was published on the preprint website arXiv on February 9. ◇#
Editor in charge: Ye Ziwei
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