The sun is in a unique position in the Milky Way-between the two spiral arms of the Milky Way. The solar system has been in a stable orbit of the Milky Way, far from the center of the Milky Way, between the two spiral arms. Usually, most stars in the Milky Way galaxy run in spiral arms. Even if some stars are not in the spiral arms, they will not stay there for a long time and will eventually be swept into the spiral arms. Only when the star is at a certain precise distance from the center of the Milky Way galaxy can the star stay between the two spiral arms for a long time. The sun is here.
Why is this important? If our solar system is within the spiral arms of the Milky Way, then the whole solar system will be greatly threatened by other celestial bodies in the universe. We are outside the spiral arms, which makes us in a very safe position in the universe because the density of celestial bodies here is very low.
The earth's unique inclination and elliptical orbit tilt the ecliptic plane by 23.5 degrees. This is important because this angle makes the earth have seasonal changes. Moreover, almost all continents on the earth are located in the northern hemisphere, because the land has a higher ability to absorb solar energy, so when the northern hemisphere points to the sun, the earth warms up, which happens to be the farthest from the sun (at this time, the earth orbit is at the apohelion), otherwise it will be hotter in summer and colder in winter.
The earth has the moon as a satellite. Because of its great mass, the moon will not be captured by the gravity of the earth. The best explanation for the moon becoming a satellite of the earth is that about 4.25 billion years ago, a planet the size of Mars hit the earth, and the moon was formed by the remnants of the impact.
However, the possibility of collision between two planets in the solar system is extremely small. And any "normal" collision will not lead to the formation of the moon, because the usual collision will not throw the projectile so far from the earth to form the moon. Computer simulation shows that the collision between asteroids and the earth must be very accurate to form the moon. Is such an accurate collision a coincidence or a design?
Why is the moon important to life on earth? Because the asteroid collided with the earth to form the moon, it also caused the original atmosphere of the earth to be ejected. If this collision hadn't happened, the earth would have an atmosphere similar to Venus, 80 times that of the earth. The greenhouse effect caused by such a thick atmosphere on Venus is very serious, which makes the surface temperature of Venus reach more than 700 degrees. If most of the earth's primitive atmosphere had not been ejected into outer space, the earth would have suffered the same fate.
In fact, the mass of the earth is 20% larger than that of Venus and farther away from the sun. These two factors should make the earth's atmosphere thicker than that of Venus. But for some strange reasons, our atmosphere is very thin, and the density is just right. There can be both solid water and gaseous water, just enough to support life. Is this a natural coincidence or an elaborate design?
Van Allen radiation shield is unique to the earth. Another lucky result of this Mars-sized planet colliding with the Earth is that the Earth has a huge and heavy metal core. In fact, the earth is the densest planet in the solar system. The huge nickel core produces our geomagnetic field. This magnetic field makes the earth form a Van Allen radiation shield, which can protect the earth from cosmic radiation. Without this shield, there would be no life on earth. Besides the Earth, the only other rocky planet in the solar system with a magnetic field is Mercury, but its magnetic field intensity is 100 times smaller than that of the Earth.
Because almost all life forms on the earth must survive at a temperature below 50℃, a planet needs a stable galaxy (only spiral, such as the Milky Way), a stable star (the star can't be too big or too small, and it can't be a binary system), a stable planetary orbit (the eccentricity of the orbit must be very small), and a suitable rotation period (a long rotation period will lead to too much temperature change).
Because the solar system meets the above requirements at the same time, we have to consider whether all this was designed by advanced civilization. It's possible, isn't it?