Extraterrestrial civilizations can fill the atmospheres of planets with greenhouse gases and this could be a technosignature for their detection. With the help of modern telescopes, it is possible to detect the existence of an extraterrestrial civilization on other planets, if the aliens, like people, emit greenhouse gases into the atmosphere. If there are a lot of such gases, then this can serve as a kind of signal about the existence of highly developed life. This is the opinion of the authors of a study published in The Astrophysical Journal, reports Space. On Earth, gases including fluorinated versions of methane, ethane and propane are known to be some of the gases that retain heat best. These greenhouse gases are released during various manufacturing processes. Since these substances are not naturally formed in large quantities, based on chemical conditions on Earth, their presence in the atmosphere of another planet may indicate that an advanced extraterrestrial civilization lives there. The authors of the study think so. According to scientists, these gases are very dangerous for the inhabitants of the Earth, because they provoke global warming. Perhaps potential aliens would like to terraform an uninhabitable planet. In this case, there may be a lot of greenhouse gases in the atmosphere. For example, aliens decided to heat up a very cold planet like Mars, in which case they will have to change its climate. If aliens terraformed such a planet, scientists found that the Webb Space Telescope would be able to detect 5 greenhouse gases in the atmosphere of this world. One of them, sulfur hexafluoride, contributes to warming the planet 23.5 thousand times more than carbon dioxide. A small amount of this gas, which has a lifespan of at least 1,000 years, is enough to melt an icy planet to the point that liquid water flows on its surface. According to scientists, their long lifespan makes these gases excellent technosignatures for the systematic search for extraterrestrial intelligence. The most interesting thing is that these gases will be able to remain in the atmosphere, even if the experiment to terrform the planet is not successful. Other similar fluorinated gases can hang around in the atmosphere for up to 50,000 years. This means that if an extraterrestrial civilization on cold planets outside the solar system is pumping a lot of greenhouse gases into the atmosphere, then this can be detected. The study authors say that even if just one in a million gas molecules absorbed the infrared radiation from its host star, it would create a signature signature that could be detected by the Webb telescope. The post Telescopes could detect alien terraforming using greenhouse gases appeared first on Anomalien.com.