Officially, in the list of dwarf planets of our system, there are 5 objects. However, there are 40 more candidates awaiting confirmation, and a multitude of potential unidentified space bodies. But what are we dealing with and where can they hide?
Promotion in status
Comparative sizes of dwarf planets
While Pluto was experiencing not the best of times, losing its planetary status, some fairly large space bodies received a boost in the world of astronomers. Officially, the term “dwarf planet” itself began to figure in the scientific community in 2006.
The found Eris made everyone think about what is the planet, after which a kind of middle class appeared. That is, the dwarf planets do not reach the full-fledged planets, but they can no longer be considered asteroids (lower in caste).
As for the planets, the MAC put forward criteria to dwarfs:
- rotation along the orbital path around the sun.
- does not act as a planetary satellite (there is no explicit gravitational binding).
- there is enough mass to create a spherical shape.
- there are still foreign objects in orbit (only the planets have the right to clear the orbital path and be gravitational dominants in the region).
Only 5 objects meet these requirements.
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Ceres
Ceres color review captured by Dawn in 2015
Appeared in the records in 1801. It was found relatively early, because it lives in the territory of the asteroid belt. In 2015, the spacecraft Dawn visited the celestial body. Initially, it was considered the first open asteroid, then a planet, and only after it acquired the status of a dwarf.
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Pluto
Pluto, shot in high resolution by the New Horizons mission in 2015
All the beloved former ninth planet ... It was lowered in the cosmic hierarchy in 2006. We have before us a wonderful trans-Neptune object with five satellites. In 2015, his research was carried out by the apparatus New Horizons, which confirmed the presence of the atmosphere.
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Haumea
Artistic vision of Haumea and her companions Hiyaka and Namaka
It is a rapidly rotating plutoid with an extremely elongated shape. There are two satellites and a possible ring system. Most likely, precisely because of the rapid revolutions around the axis, the object is fancifully stretched. The dwarf planet could appear due to the merger of two large fragments at an early stage of the system’s development.
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Makemake
Makemake, displayed by the Hubble telescope
One of the most large celestial bodies in the territory of the Kuiper belt. It spends 306 years to fly around our star, so it will take at least 3-4 human lives for a constant review. The exact weight and size is still difficult to name. Nearby rotates a tiny satellite, which was noticed only in 2016.
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Eris
Artistic Illustration of Eris
It is in second place after Pluto in size, but the most massive among the dwarf planets is considered. Became the cause of controversy among astronomers about the planetary nature of Pluto. lives on the rest from the list and for a short time was called Xena.
Where are dwarf planets hiding
Among the famous five only Ceres lives relatively close. It takes place in the asteroid belt located between Mars and Jupiter. It is much more difficult to get to the rest, because there are in the outer solar system.
You will have to search in the Kuiper belt or next to it. Let me just remind you that this giant region lives beyond the orbital path of Neptune when the system is at a distance of 30 a. e. and stretched to 55 a. e. This is a great field for searches. Somewhere here, Planet X is still capable of hiding.
How many dwarf planets can be
Comparative sizes of potential dwarf planets
There are about 40-45 candidates under consideration. The discoverer of Eris Michael Brown believes that it will be possible to find closer to 400 objects. Other scientists propose to focus on finding two hundred within the Kuiper belt and up to 10,000 dwarf candidates beyond this line.
Postscript
The problem is that the dwarf planets are small. Due to the distance it will be extremely difficult to determine the exact parameters, therefore problems with classification may arise.
