A homogenitus, anthropogenic or artificial cloud, is a cloud induced by human activity. Although generally clouds covering the sky have only a natural origin, from the beginning of the Industrial Revolution, the use of fossil fuels and water vapor and other gases emitted by nuclear, thermal and geothermal power plants yield significant alterations of the local weather conditions. These new atmospheric conditions can thus enhance cloud formation. A homogenitus, anthropogenic or artificial cloud, is a cloud induced by human activity. Although generally clouds covering the sky have only a natural origin, from the beginning of the Industrial Revolution, the use of fossil fuels and water vapor and other gases emitted by nuclear, thermal and geothermal power plants yield significant alterations of the local weather conditions. These new atmospheric conditions can thus enhance cloud formation. Various methods have been proposed for creating and utilizing this weather phenomenon. Experiments have also been carried out for various studies. For example, Russian scientists have been studying artificial clouds for more than 50 years. But by far the greatest number of anthropogenic clouds are airplane contrails (condensation trails) and rocket trails.