The cosmos is incomprehensible, its scale and magnitude are hard to imagine. The sky hides so many mysteries that, having answered one question, scientists are faced with twenty new ones. Even answering how many planets are in the solar system is quite difficult. Why? It's not easy to explain, but we'll try. Read on: it will be interesting.

How many planets are in the solar system according to the latest data

Until 2006, in all school textbooks and astronomical encyclopedias, they wrote in black and white: there are exactly nine planets in the solar system.

But the American mathematician Michael Brown was one of those who made even people far from science talk about space. The scientist initiated a revision of the concept of "planet". According to the new criteria, Pluto has dropped out of the planetary list.

The poor fellow was enrolled in a new class - "dwarf planetoids." Why did it happen? According to the fourth parameter, a planet is considered to be a cosmic body whose gravity dominates the orbit. Pluto is only 0.07 of the mass concentrated in its orbit. For comparison: the Earth is 1.7 million times heavier than anything that gets in its way.

The same class included Haumea, Makemake, Eris and Ceres, which was previously considered an asteroid. All of them are part of the Kuiper belt - a special cluster of space objects similar to the asteroid belt, but 20 times wider and heavier.

Anything beyond the orbit of Neptune is called a trans-Neptunian object. In the early 2000s, scientists discovered Sedna, a planetoid with an unusually remote and elongated orbit around the Sun. In 2014, another object with similar parameters was discovered.

The researchers wondered: why are the orbits of these cosmic bodies so elongated? It was assumed that they are affected by a hidden massive object. Michael Brown and his Russian colleague Konstantin Batygin mathematically calculated the trajectory of the planets known to us, taking into account the available data.

The results stunned scientists: the theoretical orbits did not match the real ones. This confirmed the assumption of the presence of a massive planet "X". We also managed to find out its approximate trajectory of movement: the orbit is elongated, and the nearest point to us is 200 times the distance from the Earth to the Sun.

Scientists believe that the potential ninth planet is an ice giant, whose mass more earth 10–16 times.

Humanity is already watching the proposed region of space, where there will be no known planet. The probability of an error in the calculations is 0.007%. This means virtually guaranteed detection between 2018 and 2020.

For observation, the Japanese Subaru telescope is used. Perhaps the observatory in Chile with the LSST telescope will come to its aid, the construction of which is planned to be completed in three years, in 2020.

Solar system: location of the planets

The planets of the solar system are divided into two groups:

• The first includes relatively small space bodies that have a rocky surface, 1–2 satellites, and a relatively small mass.
• The second is giant planets made of dense gas and ice. They absorbed 99% of the matter in solar orbit. They are characteristic a large number of satellites and rings that can be observed from Earth only near Saturn.

Let's take a closer look at the planets in the order of their location from the Sun:

1. Mercury is the most nearby planet to the sun. Presumably at an early stage in history, a strong collision with some object tore off most of the surface. Therefore, Mercury has a relatively large iron core and a thin crust. The Earth year on Mercury lasts only 88 days.

1. Venus is a planet named after ancient greek goddess love and fertility. Its size is almost comparable to the Earth. She, like Mercury, has no satellites. Venus is the only one in the solar system that rotates counterclockwise. The temperature on the surface reaches 400 degrees Celsius. Perhaps this is due to the greenhouse effect, which creates a super-dense atmosphere.

1. The earth is our only home so far. The uniqueness of the planet, if you do not take into account the presence of life, lies in the hydro and atmosphere. The amount of water and free oxygen exceeds that of any other known planet.

1. Mars is our red neighbor. The color of the planet is due to the high content of oxidized iron in the soil. Here is Olympus. No kidding, this is the name of the volcano, and its dimensions correspond to the name - 21 km high and 540 km wide! Mars is accompanied by two moons that are believed to be asteroids captured by the planet's gravity.

Between the terrestrial planets and the gas giants is the asteroid belt. This cluster is relatively small from 1 m to 100 km in diameter of celestial bodies. Previously, it was believed that there was a planet in this orbit that collapsed as a result of a catastrophe. However, the theory was not confirmed. It is now believed that the ring of asteroids is nothing more than an accumulation of matter left after the formation of the solar system. Roughly speaking - unnecessary rubbish.

1. Jupiter is the largest planet in the solar system. It is 2.5 times heavier than the other planets. Because of high pressure storms of hydrogen and helium rage here. The largest eddy reaches 40-50 thousand km in length and 13 thousand km in width. If a person were at the epicenter, if he survived in the atmosphere, the wind would tear him to pieces, because his speed reaches 500 km / h!

1. Saturn is considered by many to be the most beautiful planet. Known for its rings, which are made up primarily of water ice and dust. Their width on a cosmic scale is incredibly small - 10–1000 meters. The planet has 62 moons - 5 less than Jupiter. It is believed that about 4.5 billion years ago there were more of them, but Saturn swallowed them up, which is why the rings formed.

1. Uranus. Due to the nature of the rotation, this ice giant is called a "rolling ball". The axis of the planet relative to the orbit around the Sun is tilted by 98 degrees. After the "impeachment" of Pluto became the most cold planet(‒224 degrees Celsius). This is due to the relatively low temperature of the core - approximately 5 thousand degrees.

1. Neptune is this planet of blue color, which is explained by a large amount of methane in the atmosphere, which also contains nitrogen, ammonia and water ice. Remember we talked about the winds on Jupiter? Forget it, because here its speed is more than 2000 km / h!

A little about the outsider

Most likely, Pluto was not very offended that he was expelled from the planetary family. By and large, what difference does it make what people think on a distant Earth. But, one way or another, it is necessary to say a few words about the recently ninth planet from the Sun.

Pluto is the coldest place in the system. The temperature here is close to absolute zero and drops to -240 degrees Celsius. It is six times lighter and three times smaller than the Moon. The largest moon of the planet Charon is one third of the size of Pluto. The remaining four satellites revolve around them. Therefore, it is possible that they will be reclassified as a binary planetary system. By the way, the bad news - the New Year on Pluto will have to wait 500 years!

What do we end up with? According to the latest data, there are eight planets in the solar system, but, according to mathematical calculations, there should be a ninth. If you think that calculations are nothing, here's a fact for you: Neptune was discovered by mathematicians in 1846, and they could only see it up close in 1989, when the Voyager 2 spacecraft flew by. With all the scale of our house, we are just grains of sand in the space of space.

Planets of the solar system

According to the official position of the International Astronomical Union (IAU), an organization that assigns names to astronomical objects, there are only 8 planets.

Pluto was removed from the category of planets in 2006. because in the Kuiper belt are objects that are larger / or equal in size to Pluto. Therefore, even if it is taken as a full-fledged celestial body, then it is necessary to add Eris to this category, which has almost the same size with Pluto.

As defined by MAC, there are 8 known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

All planets are divided into two categories depending on their physical characteristics: terrestrial and gas giants.

Schematic representation of the location of the planets

terrestrial planets

Mercury

The smallest planet in the solar system has a radius of only 2440 km. The period of revolution around the Sun, for ease of understanding, equated to the earth's year, is 88 days, while Mercury has time to complete a revolution around its own axis only one and a half times. Thus, his day lasts approximately 59 earth days. For a long time it was believed that this planet was always turned to the Sun by the same side, since the periods of its visibility from the Earth were repeated with a frequency approximately equal to four Mercury days. This misconception was dispelled with the advent of the possibility of using radar research and conducting constant observations using space stations. The orbit of Mercury is one of the most unstable; not only the speed of movement and its distance from the Sun change, but also the position itself. Anyone interested can observe this effect.

Mercury in color, as seen by the MESSENGER spacecraft

Mercury's proximity to the Sun has caused it to experience the largest temperature fluctuations of any of the planets in our system. The average daytime temperature is about 350 degrees Celsius, and the nighttime temperature is -170 °C. Sodium, oxygen, helium, potassium, hydrogen and argon have been identified in the atmosphere. There is a theory that it was previously a satellite of Venus, but so far this remains unproven. It has no satellites of its own.

Venus

The second planet from the Sun, the atmosphere of which is almost entirely composed of carbon dioxide. It is often called the Morning Star and the Evening Star, because it is the first of the stars to become visible after sunset, just as before dawn it continues to be visible even when all other stars have disappeared from view. The percentage of carbon dioxide in the atmosphere is 96%, there is relatively little nitrogen in it - almost 4%, and water vapor and oxygen are present in very small amounts.

Venus in the UV spectrum

Such an atmosphere creates a greenhouse effect, the temperature on the surface because of this is even higher than that of Mercury and reaches 475 ° C. Considered the slowest, the Venusian day lasts 243 Earth days, which is almost equal to a year on Venus - 225 Earth days. Many call it the sister of the Earth because of the mass and radius, the values ​​​​of which are very close to the earth's indicators. The radius of Venus is 6052 km (0.85% of the earth). There are no satellites, like Mercury.

The third planet from the Sun and the only one in our system where there is liquid water on the surface, without which life on the planet could not develop. At least life as we know it. The radius of the Earth is 6371 km and, unlike the rest of the celestial bodies in our system, more than 70% of its surface is covered with water. The rest of the space is occupied by the continents. Another feature of the Earth is the tectonic plates hidden under the planet's mantle. At the same time, they are able to move, albeit at a very low speed, which over time causes a change in the landscape. The speed of the planet moving along it is 29-30 km / s.

Our planet from space

One revolution around its axis takes almost 24 hours, and full walkthrough the orbit lasts 365 days, which is much longer in comparison with the nearest neighboring planets. The Earth day and year are also taken as a standard, but this is done only for the convenience of perceiving time intervals on other planets. The earth has one natural satellite- Moon.

Mars

The fourth planet from the Sun, known for its rarefied atmosphere. Since 1960, Mars has been actively explored by scientists from several countries, including the USSR and the USA. Not all research programs have been successful, but water found at some sites suggests that primitive life on Mars exists, or existed in the past.

The brightness of this planet allows you to see it from Earth without any instruments. Moreover, once every 15-17 years, during the Opposition, it becomes the brightest object in the sky, eclipsing even Jupiter and Venus.

The radius is almost half that of the earth and is 3390 km, but the year is much longer - 687 days. He has 2 satellites - Phobos and Deimos .

Visual model of the solar system

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• Sun

  The sun is a star, which is a hot ball of hot gases at the center of our solar system. Its influence extends far beyond the orbits of Neptune and Pluto. Without the Sun and its intense energy and heat, there would be no life on Earth. There are billions of stars, like our Sun, scattered throughout the Milky Way galaxy.

• Mercury

  Sun-scorched Mercury is only slightly larger than Earth's moon. Like the Moon, Mercury is practically devoid of an atmosphere and cannot smooth out the traces of impact from the fall of meteorites, therefore, like the Moon, it is covered with craters. The day side of Mercury is very hot on the Sun, and on the night side the temperature drops hundreds of degrees below zero. In the craters of Mercury, which are located at the poles, there is ice. Mercury makes one revolution around the Sun in 88 days.

• Venus

  Venus is a world of monstrous heat (even more than on Mercury) and volcanic activity. Similar in structure and size to Earth, Venus is covered in a thick and toxic atmosphere that creates a strong greenhouse effect. This scorched world is hot enough to melt lead. Radar images through the mighty atmosphere revealed volcanoes and deformed mountains. Venus rotates in the opposite direction from the rotation of most planets.

• Earth is an ocean planet. Our home, with its abundance of water and life, makes it unique in our solar system. Other planets, including several moons, also have ice deposits, atmospheres, seasons, and even weather, but only on Earth did all these components come together in such a way that life became possible.

• Mars

  Although details of the surface of Mars are difficult to see from Earth, telescope observations show that Mars has seasons and white spots at the poles. For decades, people have assumed that the bright and dark areas on Mars are patches of vegetation and that Mars might be a suitable place for life, and that water exists in the polar caps. When the Mariner 4 spacecraft flew by Mars in 1965, many of the scientists were shocked to see pictures of the bleak, cratered planet. Mars turned out to be a dead planet. More recent missions, however, have shown that Mars holds many mysteries that have yet to be solved.

• Jupiter

  Jupiter is the most massive planet in our solar system, has four large moons and many small moons. Jupiter forms a kind of miniature solar system. To turn into a full-fledged star, Jupiter had to become 80 times more massive.

• Saturn

  Saturn is the most distant of the five planets that were known before the invention of the telescope. Like Jupiter, Saturn is made up mostly of hydrogen and helium. Its volume is 755 times that of the Earth. Winds in its atmosphere reach speeds of 500 meters per second. These fast winds combined with the heat rising from the interior of the planet, cause the yellow and golden stripes that we see in the atmosphere.

• Uranus

  The first planet found with a telescope, Uranus was discovered in 1781 by astronomer William Herschel. The seventh planet is so far from the Sun that one revolution around the Sun takes 84 years.

• Neptune

  Nearly 4.5 billion kilometers from the Sun, distant Neptune rotates. It takes 165 years to complete one revolution around the Sun. It is invisible to the naked eye due to its vast distance from Earth. Interestingly, its unusual elliptical orbit intersects with the orbit of the dwarf planet Pluto, which is why Pluto is inside Neptune's orbit for about 20 out of 248 years during which it makes one revolution around the Sun.

• Pluto

  Tiny, cold and incredibly distant, Pluto was discovered in 1930 and has long been considered the ninth planet. But after the discovery of Pluto-like worlds even further away, Pluto was reclassified as a dwarf planet in 2006.

The planets are giants

There are four gas giants located beyond the orbit of Mars: Jupiter, Saturn, Uranus, Neptune. They are in the outer solar system. They differ in their massiveness and gas composition.

planets solar system, not to scale

Jupiter

Fifth from the Sun and largest planet our system. Its radius is 69912 km, it is 19 times larger than the Earth and only 10 times smaller than the Sun. A year on Jupiter is not the longest in the solar system, lasting 4333 Earth days (incomplete 12 years). His own day has a duration of about 10 Earth hours. The exact composition of the planet's surface has not yet been determined, but it is known that krypton, argon and xenon are present on Jupiter in much larger quantities than on the Sun.

There is an opinion that one of the four gas giants is actually a failed star. This theory is also supported by the largest number of satellites, of which Jupiter has many - as many as 67. To imagine their behavior in the orbit of the planet, a fairly accurate and clear model of the solar system is needed. The largest of them are Callisto, Ganymede, Io and Europa. At the same time, Ganymede is the largest satellite of the planets in the entire solar system, its radius is 2634 km, which is 8% larger than the size of Mercury, the smallest planet in our system. Io has the distinction of being one of only three moons with an atmosphere.

Saturn

The second largest planet and the sixth largest in the solar system. In comparison with other planets, the composition is most similar to the Sun chemical elements. The surface radius is 57,350 km, the year is 10,759 days (almost 30 Earth years). A day here lasts a little longer than on Jupiter - 10.5 Earth hours. By the number of satellites, he was not far behind his neighbor - 62 versus 67. The most major satellite Saturn is Titan, just like Io, distinguished by the presence of an atmosphere. Slightly smaller than it, but no less famous for this - Enceladus, Rhea, Dione, Tethys, Iapetus and Mimas. It is these satellites that are the objects for the most frequent observation, and therefore we can say that they are the most studied in comparison with the rest.

For a long time, the rings on Saturn were considered a unique phenomenon, inherent only to him. Only recently it was found that all gas giants have rings, but the rest are not so clearly visible. Their origin has not yet been established, although there are several hypotheses about how they appeared. In addition, it was recently discovered that Rhea, one of the satellites of the sixth planet, also has some kind of rings.

How many planets are there in the solar system? Nine is the wrong answer. There are either eight or ten, or maybe twenty-one. There are even those who will say: a couple of million. Surely we will not answer this question anyway - until the International Astronomical Union finally comes to some solution with a long overdue definition of "planet".

Nobody counts anymore Pluto ninth planet. Even the most conservative astronomers admitted that this planet is more "cultural" than scientific reasons (in fact, this means that they will not lower her status, so as not to upset the people).
The discoverers of Pluto in 1930 were themselves not quite sure about this issue - why, in fact, they called it a "trans-Neptunian object", or TNO, a kind of something in the outskirts of the solar system, somewhere out there, beyond Neptune.
Pluto is much smaller than the other eight planets; it is even smaller than their seven moons. And not much larger than its own primary moon, Charon (two smaller ones were discovered in 2005). Pluto's orbit is eccentric and lies in a plane different from the rest of the planets of the solar system, plus Pluto has a completely different chemical composition.
The four planets closest to the Sun are of medium size and rocky; the remaining four are gas giants. Pluto is a tiny ball of ice, one of 60,000 small comet-like objects that at least form the Kuiper belt at the very edge of the solar system.
All of these planetoid objects (including asteroids, TNOs, and a host of other sub-classifications) are collectively known as "minor planets". To date, 330,795 such celestial bodies have been officially registered, and another 5,000 new ones are discovered every month. According to astronomers, there may be something like two million such objects with a diameter of more than a kilometer. Most of them are too small to be called planets, but twelve would give Pluto a hundred points ahead.
One of these "minor planets", discovered in 2005 and given the charming name 2003 UB313, is actually even larger than Pluto. Not far from him, the rest, like Sedna, Orcus and Quaor, also left.
It may well happen that you and I end up with two systems: the eight-planet(3) solar system and the Kuiper belt system, which includes Pluto and all the other new planets.
Such a precedent, by the way, has already been. The largest of the asteroids, Ceres was considered the tenth planet of the solar system from its discovery in 1801 until the 1850s, when its status was downgraded to an asteroid.

3
In August 2006, at the XXVI Assembly of the International Astronomical Union (IAU), astronomers from all over the world adopted the Prague Planetary Protocol. According to the text of the document, Pluto is finally deprived of the status of a “classical planet” and is transferred to “dwarf planets”. Now, according to the definition developed by the commission, only a celestial body revolving around the Sun is considered a planet, which has sufficient mass so that its own gravity exceeds the cohesive forces of solid bodies and it takes a shape close to a ball, and occupies its orbit alone (that is, "neighbors" should not be of comparable size). Thus, there are eight planets in the solar system - four terrestrial groups (Mercury, Venus, Earth and Mars) and four giant planets (Jupiter, Saturn, Uranus and Neptune). Dwarf planets (dwarf planet) are considered to be Pluto, Charon (formerly called the satellite of Pluto), the asteroid Ceres, circulating between the orbits of Mars and Jupiter, as well as the objects of the Kuiper belt - Eris (object 2003 UB313) and Sedna (object 90377). In addition, the IAU called the Pluto-Charon system a "double dwarf planet" in a Q&A.

Our solar system is rich in many interesting phenomena. Dwarf planets deserve special attention. They are objects revolving around the sun, somewhat similar to asteroids.

Dwarf planets in our solar system

Our solar system is rich in many interesting phenomena. The most attention among them deserve. All of them are objects revolving around the Sun, with some resemblance to asteroids. In this article, we will look at in general terms what it is. Then we will dwell in more detail on the dwarf planet Sedna.

Main characteristics of objects

In relation to dwarf planets, there are requirements from the International Astronomical Union. Objects must strictly correspond to them. Otherwise, they cannot be called dwarf planets, but must have a different name. So, the objects under consideration meet the following requirements:

• have a weight to maintain hydrostatic balance and have a spherical appearance;


• are not able to clear the vicinity of their own orbit from other space objects;


• revolve around the sun;


• should not be satellites of other planets.

Only six dwarf planets are known today. These include Sedna, Eris, Makemake, Haumea, Pluto and Ceres. Each of these objects differs from the other as much as the "big" planets among themselves.

It was possible to subject only two of the six "dwarfs" to the study. One of NASA's interplanetary stations is still orbiting one dwarf planet - Ceres. High-quality images of the surface of a celestial body were obtained. Photos taken by AMC Dawn. This is an advanced spacecraft. Its engines operate on ion propulsion. Therefore, with the help of AMC Dawn, it became possible to study several space objects at once.

It was this apparatus that entered the orbit of an asteroid for the first time in history and collected all the necessary information about it. After which he retired to study the next celestial body - the dwarf planet Ceres. The use of this automatic station made it possible to make a breakthrough in the study of the main asteroid belt. AMC Dawn has created an accurate and detailed map surfaces of asteroids and dwarf planets.

Two years ago, the New Horizons spacecraft made its first close approach to the largest of the six objects, Pluto. As a result, images of its surface were also obtained. Appearance the rest of the dwarf planets is not known to mankind today.

The list of considered objects can be replenished. Astronomers have about forty candidates for the title of "dwarf planet". All of them are located outside of Neptune. But there is no unambiguous data about these objects. Therefore, while they are not officially classified as dwarf planets. There is also an opinion that at least two thousand objects of this type are located in the Kuiper belt, the Oort cloud and the scattered disk.

It is safe to say that extrasolar dwarf planets also exist. But nowadays they are unlikely to be open. Modern telescopes do not provide such an opportunity. But science does not stand still. Perhaps in the near future we will learn a lot of interesting things.

Sedna: what do astronomers know?

There is a popular theory according to which the Sun stole several hundred dwarf planets and asteroids from another star flying nearby by means of its gravity. For the most part, this was all considered a bold assumption. But today there is already some evidence for this hypothesis.

Astronomers have been drawn to the dwarf planet Sedna. She and several neighboring celestial objects move in rather strange orbits. In particular, Sedna is the most distant object in our solar system. At the same time, the nearest point of its orbit is located at 76 AU from the star, and the farthest point is located at 1007 AU. e. This object has a huge orbital period. It is eleven thousand four hundred and eighty-seven years. It is considered the longest among large celestial bodies.

Scientists have tried to figure out the nature of this strange behavior sednoids. The first attempt was made in 2003. That's when they were opened. At first, scientists could not find a rational explanation. Then a theory was put forward that the orbits of the sednoids were elongated by a star flying about four billion years ago.

Subsequently, computer simulation of the previously described hypothesis was carried out. It happened at the Leiden Observatory. It turned out that a nearby star did not affect the orbits of the sednoids. Rather, it was the Sun that drew them to itself.

During the study, more than ten thousand variations of scenarios were taken into account, which took into account different combinations distances, passage speeds and masses of stellar systems. The simulation was carried out under the guidance of the famous astronomer Lucy Zhilkova.

The performed calculations made it possible to calculate the most probable scenario. The star passing by was eighty percent larger than the Sun. The approach indicator reached a maximum of about thirty-four billion kilometers. In this case, the exchange of objects occurred from two sides. Some of the objects were added to the orbit of the Sun, some, on the contrary, went to another system. This event most likely took place about four billion years ago.

The work carried out by Zhilkova received good feedback and recognition by scientists around the world. At the same time, do not forget that this is just a theory, albeit highly probable. It still requires further confirmation. This can be achieved by performing chemical analysis. If its results differ from data from trans-Neptunian objects, this will mean that the sednoids are of alien origin. It is not possible to see the results of this analysis in the near future.

There is also a theory that claims the existence of not yet open planet, whose orbit is located in hundreds of a. e. from the Sun. It is she who makes adjustments to the flight path of Sedna. Again, this is just a bold assumption that requires serious scientific study.

Results

There are many gaps in the study of dwarf planets. But with the development of new space exploration technologies, all of them will be quickly replenished. Modern scientific stations pay great attention to the study of this issue.

Definition of the concept of dwarf planets according to international standards

The International Astronomical Union (IAU) has given a definition of space objects that will be called dwarfs. So dwarf planets are considered that have the following features:

• Object revolves around ;
• The mass of the object is sufficient to become almost round;
• An object cannot use its gravity to clear its path on its own.

The main differences between the dwarf and the terrestrial group of planets

The difference between these planets and the Earth group lies in the inability of a space object to clear a path in front of itself, that is, others, such as or Mars, can clear a path in front of them in their orbit with their mass. Unlike large ones, these planets, as a rule, cross in their orbits the places of accumulation of other cosmic bodies, for example, the Kuiper Belt.

To date, astronomers have managed to detect and classify five such objects:

1. Pluto(the well-known planet, which at the meeting of the ISO in 2006, was reclassified from a planet to a dwarf one).
2. Ceres is a dwarf planet between Mars and Jupiter in the asteroid belt.
3. Makemake- little studied, the third largest dwarf planet in the solar system.
4. Haumea- unusual for very fast rotation around its axis.
5. Eris- in terms of mass, it is the second dwarf planet after Pluto, although it is possible that the first data is being specified.

However, according to some scientists, it may contain about 100 or more small dwarf planets they just haven't been discovered yet.

The International Astronomical Union has designated the planets beyond Neptune as "Plutoids".

So it is believed that Eris, which revolves around the Sun far beyond the orbit of Neptune, becomes plutoidhome, and Ceres from the Asteroid Belt becomes a dwarf planet.

Table of dwarf planets with astronomical characteristics

dwarf planets
	Location	asteroid belt
	Dimensions (km)	975×909
	Weight in kg. Relative to the Earth	9.5 10 20 0,00016
		0,0738 471
		0,51
	Rotation period (days)	0,3781
		0
	opening date	01.01.1801
Pluto	Location	Kuiper belt
	Dimensions (km)	2306±20
	Weight in kg. Relative to the Earth	1.305 10 22 0,0022
	Mean equatorial radius in km	0,180 1148,07
	First escape velocity (km/s)	1,2
	Rotation period (days)	−6.38718 (retrograde)
	Number of known satellites	5
	opening date	18.02.1930
Makemake	Location	Kuiper belt
	Dimensions (km)	1500×1420
	Weight in kg. Relative to the Earth	?
	Mean equatorial radius in km	?
	First escape velocity (km/s)	?
	Rotation period (days)	0.32
	Number of known satellites	1
	opening date	31.03.2005
Eris	Location	Scattered disk
	Dimensions (km)	2326±12
	Weight in kg. Relative to the Earth	~1.67 1022 0,0028
	Mean equatorial radius in km	0,19 ~1300
	First escape velocity (km/s)	1.3
	Rotation period (days)	≈ 1 (0.75–1.4)
	Number of known satellites	1
	opening date	5.01.2005
Haumea	Location	Kuiper belt
	Dimensions (km)	1960×1518×996
	Weight in kg. Relative to the Earth	4.2 1021 0,0007
	Mean equatorial radius in km	~750
	First escape velocity (km/s)	0.84
	Rotation period (days)	0.16
	Number of known satellites	2
	opening date	28.12.2004
Sedna	Location	Oort cloud
	Dimensions (km)	995±80
	Weight in kg. Relative to the Earth	8.3 1020-7.0 1021
	Mean equatorial radius in km	?
	First escape velocity (km/s)	?
	Rotation period (days)	0.42 d (10 h)
	Number of known satellites	0
	opening date	14.11.2003

Other dwarf planet candidates

Thanks to modern means During the discovery, scientists discovered several dozen large cosmic bodies that can be attributed and qualified as the Plutoids planets. The table below shows planetoids with an approximate diameter of up to 600 km. Moreover, the first 6 objects are likely to become the main candidates.