A popular misconception is to consider the hottest Mercury as the smallest planet, the planet closest to the Sun. In fact, the smallest planet is the cold and distant Pluto. Some refuse him the status of a planet in general, but this is a moot point, the status of Pluto has not been proved, and the non-planetary status is nothing more than a "journalistic fact". The second largest planet is indeed Mercury. The planet Pluto was named after the god of the underworld of the Romans, and this name should be considered quite logical. Pluto receives far less sunlight than Earth.
World of mystery
Powerful telescopes have been available to humans for only the last few decades, and the planet Pluto was officially discovered in 1930. In 1915, it was officially announced that on the outskirts of the solar system there is a ninth planet. How was this little celestial body calculated? A body whose mass is comparable to that of the moon inevitably exerts a gravitational influence on its neighbors. Observers noted that Uranus and Neptune deviate slightly from the calculated orbits, and this led to the existence of the most mysterious planet of the observed.
Under the ice
Pluto is an inhospitable planet. It is assumed that its atmosphere consists of methane gas, and the surface is covered with methane ice. Cold reigns there (the usual temperature is less than 200 degrees below zero Celsius). By the way, theoretically, he may collide with Neptune (their orbits overlap), but the probability of such an event is very small, the orbits of distant planets are too huge.
Two in one
However, the position of Pluto (as a separate planet) is ambiguous. The fact is that the smallest planet in the solar system has a huge satellite for its size. And the rotation speed of Pluto around its axis coincides with the rotation speed of Charon around it. He seemed to be frozen over one point on the planet. Therefore, if there was life on Pluto, the inhabitants of only one hemisphere would see a satellite called Charon. It is logical to even consider this pair a double planet, the red satellite is so large. Scientists believe that Charon consists of rocks. But no one can say for sure until they have taken samples of the substance from the surface.
Where is the planet from?
As soon as Pluto was discovered, scientists began to guess where the smallest planet of the solar system came from. And it turned out to be the most logical to consider the baby planet a former satellite of Neptune. It seems that Pluto itself does not have metallic rocks as its satellite, but consists of ice. The secrets of its orbit have not yet been discovered by astronomers (like the secrets of some of Neptune’s icy satellites), but a certain similarity can be traced. But why did this happen? Perhaps Pluto is knocked out of orbit by a flying very large asteroid or comet. However, then where is Charon? Some believe that this is part of Pluto in the past. But this is unlikely, because the composition of the planet and satellite is very different.
It is difficult to say something for sure about a celestial body that is so far from us. The smallest planet in the solar system keeps its secrets. And it will be stored for a very long time, mainly because of the huge distance separating it from the Earth.
In 2006, reports appeared that Pluto is not a planet at all, but part of the asteroid belt. But in books and studies, Pluto is the ninth planet of the solar system. Therefore, all the same, the status of the smallest planet should have Pluto, and not Mercury.
