In the spring of 3067 in the Earth's calendar (AD), human beings already had very advanced high technology. At this time, there were more and more rumors of aliens visiting the earth. Although most of them were aircraft or natural phenomena made by humans themselves, there were still a small number that people could not explain.
At this time, humans have regarded the earth, the planet that was once the cradle of humankind and countless lives, as a huge energy bank, constantly using the earth's energy - geothermal energy, and at the same time mining the earth's radioactive heavy nuclides (such as uranium 235, plutonium 239, etc., Used as nuclear fission power stations) and some light nuclear nuclides (mainly deuterons and tritium nuclei, used as nuclear fusion power stations - humans have mastered the controllable reactions of nuclear fusion). But humans no longer live on the earth. In the space of the solar system, there are countless giant space stations. Some of them orbit the earth and become a group of satellites of the earth, and people live in them. There are also some orbiting Mars. They are mainly completing the preparations before immigrating to Mars: such as transforming the Martian environment and turning the thick carbon dioxide in the Martian atmosphere into breathable oxygen. Of course, there are also space stations for military purposes, because humans have never stopped competing and will never stop competing. Various countries have a "cold war" with each other, but this has also promoted the development of human science and technology, allowing them to still have the ability to continue the race even after the earth's environment has become uninhabitable.