Civilization on another planet, seems to be highly unlikely. Hypothetically if the possibilities for any celestial body closest to us to harvest life, most astrobiologists feel Europa or Mars to have the best conditions to make this possible. The environment of Mars suggest at one point it did contain water and could have the potential with much terrain like Earth, and Europa is thought to have a large ocean to harvest potential life The issue is having all the variables just right in order for this to be a possibility of the near future.
Sub Question #1 What conditions are needed for life to exist on another planet? The many of all conditions needed is a long complex list to make life an essential. The Drake equation is apart of this list, a renound mathematical formula that estimates the amount of celestial bodies in various galaxies. The equation N=f* fp ne fl fi fc fl, N= the amount of stars in our galaxy(the milky way), f*= the percent of stars that planets revolve around, ne= amount of stars planets per a star able to maintain life, fl= percent of the planets that life can develop, fi=the amount fi that has potential to develop intelligent life, fc=the percent of fi of potential communication, and fl= the percent at which the civilization can withstand survival with communication. This equation was first presented by Frank Drake in 1961 and ever since has been used as a basic calculation for the SETI( search for extraterrestrial intelligence). SETI is an organization that was developed for astrobiology in search for alien life. Astrobiologists believe that there is around 800 to 100 billion habitable planets in our galaxy and others. The issue is having them meet all the conditions to make life possible. In order for life to develop in our galaxy, the celestial body needs to be in the habitable zone. Known as the goldy locks region of the milky way. This region is located where Earth is, so any exoplanets near this region could be considered for potential life but as well many other variables must be present in order to follow through. Some stars could be capable of this if they didn't have such harsh ultraviolet rays and the life expectancy was extend. Mostly low mass stars would be a better fit for life around the habitable region due to their longer life expectancy. The bigger stars intend to burn their energy much faster with nuclear fusion, because they need more hydrogen and helium bondage to support their massive structure. Smaller stars can live from 80-100 billion years, while massive stars only 10-20 million years. In order for life to evolve of stars in the goldy locks zone water must be present. Water is the most vital part of life, without water no life can't exist. In order for water to exist the atmosphere must come to a thermal equilibrium. A thermal equilibrium is the ratio between when the radiation from a neighboring star is absorbed and the radiation emitted from the planet is equal. Water and green house gases created works as an insulator to cool down the planet, while the radiation warms it up to make the perfect atmosphere that provides carbon and oxygen. Such moons like Saturn's moon Europa, Ganymede and Callisto has abundance of methane, water vapor and ammonia, would be great if it came to a thermal equilibrium and didn't have such critical conditions. If water can form, then this can allow for more complex elements to evolve. Organisms are made of infinite complex chemical compounds. This sets the building blocks of evolution. If the atmosphere contains elements of carbon or ammonia, that can be the start. The issue is maintaining the population to adapt and thrive. The environment must allow the ability to recycle itself. Earth is an example with plate tectonics. When carbon levels fluctuate, Earth is able to adjust to the