Astronomers believe that according to the new classification of planetary systems, our star system is the rarest case in space.
Swiss scientists have created a new classification of planetary systems based on existing data on already discovered exoplanets and their location in their star systems. The results of the study showed that our solar system belongs to the rarest type of planetary systems, writes New Atlas.
At Focus. Technologies has its own Telegram channel . Subscribe to not miss the latest and exciting news from the world of science!
Several decades of searching for planets that are outside our star system have made it possible to discover 5,300 exoplanets today, which have different compositions and different sizes. They are also arranged differently around their parent star. It is already known that all the above planets are located in 3910 planetary systems at different distances from the Earth.
Thanks to the available data, which were obtained as a result of careful observations, astronomers divided all the discovered planets into separate types:
- Rocky planets like Earth or Mars;
- Gas giants such as Jupiter or Saturn, but they can be much larger;
- Super-Earths, that is, planets similar to the Earth, but several times larger;
- Mini-Neptunes, that is, planets that are similar to Neptune, but smaller in size;
- Water worlds, that is, rocky planets with a predominance of water in their composition.
Scientists from the University of Bern, Switzerland, decided to classify the types of planetary systems that are already known to astronomers on the same principle. The main question was whether our solar system is a common type of planetary systems, or is it still unique? As the study showed, indeed, the solar system is the rarest type of planetary systems.
In order to come to this conclusion, scientists studied 853 star systems in which there are several planets. Based on known data, astronomers have identified 4 main types of planetary systems that exist in space:
- Similar planetary systems are systems that are most common in space, according to scientists. Several planets of approximately the same size revolve around a star in such systems. And often they are similar in size to the Earth.
- Ordered planetary systems are systems in which a group of rocky small planets revolve around a star at a close distance from it, and further there are larger gas and ice giants. Scientists believe that this is the rarest type of systems in terms of the location of the planets and the solar system is included in this group.
- Disordered planetary systems are systems in which, on the contrary, large planets are closer to the star, and smaller ones are at a considerable distance.
- Mixed planetary systems are systems in which there seems to be no clear configuration and the reason for this is not yet known.
According to scientists, the location of the planets in a star system, as well as their type and size, depends in part on the initial conditions in which a given system appeared. For example, what size and mass was the protoplanetary disk of gas and dust surrounding the star, from which the planets appeared, and also how much heavy metals were in the composition of the star. In fact, in astronomy, all elements heavier than hydrogen and helium are called metals. Scientists also believe that the location of the planets is affected by their movement at the initial stage of the evolution of the planetary system.
- Similar planetary systems form from small, low-mass protoplanetary disks orbiting a star with small amounts of heavy metals, astronomers say.
- From large and heavy protoplanetary disks that revolve around a star with a large amount of heavy metals, ordered and disordered planetary systems are formed.
- Mixed planetary systems arise from medium-sized protoplanetary disks.
Astronomers believe that interactions between planets, such as collisions and further orbital changes, lead to the formation of the final structure of a star system.
It is now known that there are 8 planets in our solar system (Pluto has been a dwarf planet since 2006). But all evidence points to the fact that somewhere out there, on the edge of our star system, Planet Nine is hiding . As Focus already wrote , scientists have proposed a new way to detect it.
Also, scientists have known for more than 20 years that our Universe is constantly accelerating its expansion and behind this is the mysterious dark energy . As Focus already wrote , scientists have found the source of this energy, and it is most likely hiding in a long-known space object.