Space

Why does Venus and Mercury have no natural satellites?

Absolutely all the planets of the solar system, beyondwith the exception of Venus and Mercury, they can boast of having at least one stable satellite orbiting one or another planet. So, even Pluto, recently demoted from the planetary status, can boast a huge satellite relative to its size - Charon. How did it happen that two full-fledged planets - Mercury and Venus - were without satellites?

Despite all its similarities with the Earth, Venus does not have its own satellites

Mercury could be a satellite of Venus

There are at least 2 theories of whybut the first two planets to the Sun show the absence of any satellites. One of the most original theories says that at one time Mercury was a satellite of Venus, as indicated by the similarity of its surface with the surface of our moon.

According to this hypothesis, after about 500million years after the formation of the solar system, Mercury, which at that time was still a satellite of young Venus, somehow escaped from its gravitational embrace and set sail freely to the Sun, where it found its own orbit. Such a development of events led to a powerful heating of the surface of Venus and the appearance of a dense atmosphere with a high content of sulfuric acid. Well, it seems that the planet was angry in earnest after such an unceremonious rupture.

See also: Venus has turned into a hellish planet due to the tides of the ancient oceans

Slowly rotating planets cannot have satellites

One of the theories that could explainthe absence of satellites in Venus and Mercury, is the hypothesis of too slow rotation of these planets around its axis. It is known that a day on Mercury lasts about 58 Earth days, while on Venus this figure is equal to 243 days. Due to the extremely low speed of rotation of the planets, their stationary orbits, which theoretically could have hypothetical satellites, are located very far from the surface of these planets. According to the laws of gravitodynamics, all objects located below a stationary orbit will gradually decrease in a spiral to their planet until they are attracted by gravity and fall to the surface of their cosmic host. So, we can already observe a similar phenomenon in the orbit of Mars, whose satellite Phobos is gradually decreasing and after about 3 million years will be in the gravitational trap of its planet, which will cause it to rapidly fall onto the red surface of Mars.

The rotation speed of Mercury around its axis is extremely low, which could serve as a factor in its lack of a natural satellite

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The theory of satellites falling on planets with slowrotation can be confirmed by the strange rotation of Venus, which is opposite to the standard direction of movement of the planets of the solar system around its axis. In other words, a satellite that fell to the surface of Venus could radically change not only its climatic features, but also literally turn the planet upside down, the consequences of which we can observe today.