The moon is the earth's only natural satellite and the closest large celestial body to the earth, with an average distance of about 380,000 km from it. For the formation of the moon, some scientists believe it may have been a collision with the earth more than four billion years ago by an object that may have been the size of mars. That violent impact lifted a huge amount of dust from the earth's surface, and this dusty material eventually converged to form the moon. Since that time, the moon has been in orbit around the earth.

There are also some views that the moon itself is an already existing celestial body. More than 4 billion years ago, the cosmic space environment of the solar system was still chaotic, with all kinds of small objects scurrying around, and when the moon, a celestial body, came near the moon earth, it was bound by the earth's strong gravitational force and was eventually captured by the earth's gravity into an orbit around the earth, becoming a satellite of the earth.

Although the moon should have existed for about the same amount of time as the earth, more than 4 billion years, and it is also in the habitable zone of the solar system, after all it is in the vicinity of the earth, and the space environment to which the earth belongs should be similar, for example the radiation from the sun or from the depths of the universe should be similar, but the environment on the surface of the moon is very different from that of the earth.

For example, the earth has a dense atmosphere, a magnetic field, and liquid water at the right temperature to make it a planet suitable for life. The earliest primitive microorganisms appeared on earth more than three billion years ago, and after billions of years of evolution, the planet has emerged as a vibrant place for life. In contrast, the moon's environment is much harsher, for example, the surface is extremely dry, there is no atmosphere, and the temperature difference between day and night on the moon's surface is so great that it is clearly not a world suitable for life. In such a harsh environment as the moon, it is impossible for so-called aliens to exist.

There are no people or other living things on the moon, but scientists have found a lot of rubbish on the surface of the moon, which is very strange, if there are no people on the moon, why would so much rubbish appear? Could it be that these outer these rubbish appeared out of thin air by themselves or that aliens dropped them on the surface of the moon?

Although there are no people on the moon, humans have explored the moon since the 1950s, especially after the apollo 11 spacecraft achieved a manned lunar landing in 1969, and five other apollo moon landing spacecraft also completed lunar missions, leaving 12 astronauts on the surface of the moon. These lunar astronauts did not stay on the lunar surface for long, but they did leave some household rubbish on top of the moon, such as boots, which became the lunar rubbish.

Then there may be some friends feel confused, in so many years, also only 12 astronauts successfully landed on the moon, by definition, they should not leave a lot of living rubbish, after all, their stay is not long, usually just a few hours, such a short time, they left not much rubbish, then the lunar surface of more than 180 tons of rubbish is where to come from?

The rubbish mentioned here is not only the domestic rubbish left by the astronauts, but also many man-made objects. For example, the lunar module of the apollo moon spacecraft landed on the surface of the moon, and when the astronauts returned to earth, the descent stage of that module was left on the surface of the moon, and the lunar rover that the apollo moon astronauts drove on the surface of the moon was also left on the surface of the moon, and all of these man-made objects eventually became rubbish. In addition to the apollo moon landings, a large number of probes have been launched to explore the moon, which also end up as rubbish when they land on the surface. For example, the indian moonship 2 probe crashed on the surface of the moon during its landing and was eventually turned into rubbish. More recently, a four-ton rocket wreckage also hit the surface of the moon, sending a cloud of dust hundreds of kilometres high. This rocket wreckage also left nearly four tonnes of rubbish on the surface of the moon after it hit the moon.

It is from the human launches of lunar landing craft, lunar probes and other explorations of the moon that scientists have extrapolated the amount of rubbish that has appeared on the surface of the moon to date, which includes the household rubbish of the lunar landing astronauts, as well as these lunar rovers and lunar probes.

So it is to be expected that rubbish will appear on the moon, even though there are no people on it. This is because as humans continue to explore the moon, these man-made objects will continue to be sent to the surface of the moon, and when these man-made probes have completed their mission of exploring the moon, they will slowly turn into rubbish. So the rubbish that exists on the moon is not left behind by aliens, but sent up by us humans.