How is a double planet different from a planet and a satellite

In astronomy, there is such a thing as a double system of planets. But this is not the same as the planet and its

satellite. So what is the difference between them?

Discuss

From a scientific point of view, a double planetary system– these are two celestial bodies that are close to each other and that have the same mass. However, scientists have not yet identified clear criteria by which to distinguish between a double planetary system (double planet) and a “planet –” system. moon" (or "planet & #8211; satellite").

The most obvious difference between one and the other is the ratio of the masses of the two space objects. If it is close to unity, then these objects are similar in mass.

So, in the Earth system – Moon” this ratio is 0.01230, in the “Pluto –” system. Charon" – 0.122. Neither one nor the other can be characterized as a double planetary system.

Other delimitation criteria have been proposedthese two concepts. For example, one of these criteria – the location of the "barycenter", that is, the point around which two objects rotate. According to this criterion, the binary planetary system (double planet) is Pluto and Charon, and the Earth and Moon – No.

However, none of the criteria has been accepted by scientists as official.