The solar system is teeming with satellites. As many as 79 moons revolve around Jupiter, and Saturn is able to boast a family of 62s. Even we have a beloved Moon accompanying humanity in the night sky. Then why is Venus unlucky? Where are her companions?
Yes, Venus does not have satellites. In this regard, her sad fate is also shared by Mercury. But the situation of Venus is a bit surprising. Indeed, in terms of composition and parameters, this is practically a terrestrial twin. The planet is relatively close to us. Moreover, at the stage of the formation of the solar system, the space was filled with a huge number of fragments. Did they not have enough to create another satellite for Venus?
Let's first understand how the planets generally get the moon. There are three options:
- capture. It is believed that this happened with the Martian satellites Phobos and Deimos. Already completed large objects drift around the system until the gravitational force of one of the planets draws them to itself.
- collision. This is the most likely way to form our Moon. A huge object smashes into the planet, pieces of material are separated, merged and create a number of gravitationally bound satellite.
- general formation. That is, the satellite appeared next to the planet as early as the development of the solar system.
That is, the planet has many opportunities to get its own satellite. What is wrong with Venus? Researchers are convinced that once a satellite (or even satellites) revolved around the planet. However, there was some kind of event that caused him to be destroyed or retired. Therefore, the main theories are trying to explain why Venus does not have a satellite, but where he could go.
Comparative sizes of Venus and Mercury
There is a huge number of theories, among which many seem rather fantastic. For example, some are convinced that the satellite of Venus all this time remained in plain sight. This is Mercury! Yes, he just walked away from the planet and became a full-fledged world.
There is also an assumption that many small collisions led to a distortion of gravity, and Venus simply could not hold the satellite, which moved to the Sun and burned. Several other hypotheses also lead us to the fact of the moon running away. But the snag is that external drift lasts billions or tens of billions of years. The satellite would not have time to escape.
The last study put forward a theory that seems most likely. Scientists have decided that the answer may be hiding in the speed of rotation of the planet. One axial rotation takes 243 days, with rotation in the opposite direction. Therefore, researchers suspect that two major blows occurred in the past.
Mercury, Venus and Moon in the sunset sky
The first collision led to the fact that the planet began to rotate counterclockwise. In this process, a satellite emerged from the fragments, which began to drift slowly, like the Earth's Moon. Then came the second blow, which caused the planet to rotate clockwise (in the opposite direction).
The changes affected the gravitational contact of the satellite and the planet, which is why the moon of Venus did not start to run away, but rather converge with the world. In the end, she could just crash into Venus. Some believe that another satellite could have occurred during the second collision. But the approach of the moon from the first strike is boldly still a developing satellite from the second impact (one moon, falling on the planet, destroyed the second).