Earth is not the only inhabited planet in the universe
Observing the stars, man understood that our Earth is only a planet of a small solar system bordering a branch of our galaxy, the Milky Way, which is a hundred thousand light-years in diameter.
1 / The man also understood that observing the stars, he observed his cosmic past, since, for example, the sunlight was emitted 8 minutes before we tan, and the galaxies we see today are as they were a few thousand or millions of years ago, but to observe them as they are today, we would have to project ourselves into the future ... which means that everything we perceive has already occurred!
2 / The telescopes and satellites responsible for observing the universe have discovered that our galaxy is part of a well-ordered cluster of galaxies which itself is part of a super-cluster of galaxies whose size is 500 million light years. It has been observed that movements between galaxies are organized, like water, in currents, falls and deltas by a super-attractor of masses appearing to be in the center.
3 / Our universe visible and observed by our telescopes (barely 7% estimated from the real universe) contains thousands of super-clusters of galaxies that contain hundreds of billions of solar systems and thousands of billions of planets where the life is plentiful for at least 10% of them (according to the Drake equation) and not necessarily at the primitive stage, we must face the fact that we are certainly not the only civilization in the universe!
4 / Another point which obliges us to a certain humility: the normal atomic material of which we are made and which composes the planets, the stars, the asteroids, the galaxies, the stellar gases represents only 5% of the mass of the universe !!! This is only a tiny part of a universe composed mainly of dark matter (26% of the mass of the universe) and dark energy (69% of the mass of the universe) that could contain other forms of biological life still unknown, or forms of non-biological life, much more abundant than our biological life ...
5 / We, the earthlings who have been launching satellites in Space for a little more than half a century, are in the humble position of a baby who begins to explore his room from his cradle ... and who, sometimes, is confronted with displacements in other rooms of the apartment and even outside, in a stroller, how could this baby imagine that he lives a city in a region of France, la-dit France is part of Europe, one of the five continents of the Earth, planet being part of a solar system ... etc. Could this baby decree that only his visible environment is the only reality, and that the human beings he sees and of which he is aware are the only living beings in the whole of reality and that nothing else exist ?
This is why the human being continues to ask questions and spends billions of euros in the exploration of the cosmic space because he can not exclude that humanity can be part of a more global evolution!