Pluto is a planet that received the name of a mythological deity. For a long time it was the last, ninth planet of the solar system. Pluto was considered not only the smallest, but also the coldest and least studied. But in 2006, with the goal of a more detailed study, the device was launched, which in 2015 reached Pluto. His mission will end in 2026.
The size of Pluto is so small that since 2006 it has ceased to be considered a planet! However, many call this decision far-fetched and unreasonable. Perhaps soon Pluto will again take its former place among the cosmic bodies of our solar system.
The most interesting facts about Pluto, its size and the latest research are below.
Planet discovery
Back in the 19th century, scientists were convinced that beyond the Uranus is another planet. The power of the then telescopes did not allow them to detect it. Why was Neptune so eagerly searched? The fact is that the distortions of the orbits of Uranus and Neptune could only be explained by the presence of another planet behind it, which affects it. As if "pulling" on itself.
And in 1930, Neptune was finally discovered. However, it turned out to be very small in order to cause such disturbances of Uranus and Neptune. Moreover, its axis is as inclined as the axes of Uranus and Neptune. That is, the effect of an unknown celestial body affects him.
Scientists are still looking for the mysterious planet Nibiru, wandering around our solar system. Some are sure that it can soon become the cause of the ice age on Earth. However, its existence has not yet been confirmed. Although its description, researchers suggest, is in the ancient Sumerian texts. But even if the killer planet really exists, we should not be afraid of the end of the world. The fact is that we will see the approach of a celestial body 100 years before its alleged collision with the Earth.
And we will return to Pluto, discovered in 1930 in the state of Arizona by Clyde Tombo. The search for the so-called planet X has been conducted since 1905, but only a team of American scientists managed to make this discovery.
The question arose which name to give to the discovered planet. And to call her Pluto was proposed by the eleven-year-old schoolgirl Venice Burnie. Her grandfather learned about the difficulties in finding a name and asked what name the granddaughter would give the planet. And Venice very quickly gave a reasoned answer. The girl was interested in astronomy and mythology. Pluto is an ancient Roman version of the name of the god of the underworld of Hades. Venice explained its logic very simply - this name was in perfect harmony with the silent and cold cosmic body.
The size of the planet Pluto (even more so in kilometers) remained unspecified for a long time. In telescopes of those times, the ice kid was seen only as a bright star in the sky. It was completely impossible to determine its mass and diameter. Is he bigger than the earth? Perhaps even more than Saturn? Questions tormented scientists until 1978. It was then that the largest satellite of this planet, Charon, was discovered.
What is the size of Pluto?
And it was the discovery of its largest satellite that helped establish the mass of Pluto. They called him Charon, in honor of the otherworldly creature transporting the souls of the dead to the underworld. The Charon mass was still known quite precisely then - 0.0021 Earth masses.
This made it possible to find out the approximate mass and diameter of Plato, using Kepler's formulation. In the presence of two objects of different masses, it allows us to conclude about their sizes. But these are only approximate figures. The exact dimensions of Pluto became known only in 2015.
So, its diameter is 2370 km (or 1500 miles). And the mass of the planet Pluto is 1.3 × 10 22 kg, and the volume is 6.39 · 10 9 km³. Length - 2370.
In comparison, the diameter of Eris, the largest dwarf planet in our solar system, is 1,600 miles. Therefore, it is not surprising that in 2006 they decided to assign Pluto the status of a dwarf planet.
That is, it is the tenth most severe object in the solar system and the second among dwarf planets.
Pluto and mercury
Mercury is the planet closest to the Sun. He is the exact opposite of the icy baby. When comparing the sizes of Mercury and Pluto, the latter loses. After all, the diameter of the planet closest to the Sun is 4879 km.
The density of two "babies" also varies. The composition of Mercury is mainly represented by stone and metal. Its density is 5.427 g / cm3 . And Pluto at a density of 2 g / cm3 contains mainly ice and stone. It is inferior to Mercury in gravity. If you were able to visit the dwarf planet, at every step you would come off its surface.
When in 2006 Pluto was no longer considered a full-fledged planet, the title of space kid again went to Mercury. And the title of the coldest received Neptune.
The dwarf planet is also smaller than the two largest satellites of our solar system - Ganymede and Titan.
Sizes of Pluto, Moon and Earth
These celestial bodies also vary in size. Our moon is not the largest satellite in the solar system. In fact, experts have not yet decided on the interpretation of the term "satellite", perhaps someday it will be called a planet. However, the size of Pluto, in comparison with the Moon, is clearly losing - it is 6 times smaller than the Earth’s satellite. Its size in kilometers is 3474. And its density is 60% of the Earth’s and second only to Saturn’s satellite Io among the celestial bodies of our solar system.
And how much is Pluto smaller than Earth? A comparison of the sizes of Pluto and the Earth clearly shows how small it is. It turns out that 170 “plutonics” would fit inside our planet. NASA even presented a graphic depicting Neptune located on Earth. It is impossible to explain better how their masses differ.
Sizes of Pluto and Russia
Russia is the largest country on our planet. Its surface area is 17 098 242 km². And the surface area of Pluto is 16.65 million square kilometers. A comparison of the sizes of Pluto and Russia in the human sense makes the planet completely insignificant. Is Pluto a planet at all?
Scientists are sure that the planet can be considered that celestial body that has clean space. That is, the planet’s gravitational field must either absorb the nearest space objects, or throw them out of the system. But the mass of Pluto is only 0.07 of the total mass of nearby objects. For comparison, the mass of our Earth is 1.7 million times the mass of objects in its orbit.
The reason for including Pluto in the list of dwarf planets was another fact - in the Kuiper belt, where the space baby is also located, larger space objects were discovered. The final touch was the discovery of the dwarf planet Eris. Michael Brown, who discovered it, even wrote a book called How I Killed Pluto.
In fact, scientists, reckoning Pluto to the nine planets of the solar system, understood - this is a matter of time. Once the cosmos goes explored further than Pluto - and there are bound to be larger cosmic bodies. And to call Pluto a planet will be incorrect.
Formally, Pluto is called a dwarf planet. But in fact, full-fledged planets do not fall under this classification. This term was introduced in the same 2006. The list of dwarfs includes Ceres (the largest asteroid in our solar system), Eris, Haumea, Makemake and Pluto. In general, far from everything is clear with the term dwarf planets, since they have not yet come up with a precise definition.
But, despite the loss of status, the ice baby remains an interesting and important object to study. After considering how large Pluto is, let's move on to other interesting facts about it.
The main characteristics of Pluto
The planet is located at the very edge of our solar system and is 5900 million km away from the Sun. Its characteristic feature is the elongation of the orbit and a large slope to the plane of the ecliptic. Thanks to this, Pluto can approach the Sun closer than Neptune. Therefore, from 1979 to 1998, Neptune remained the planet farthest from the heavenly luminary.
A day on Pluto is almost 7 days on our Earth. A year on the planet corresponds to our 250 years. During the solstice ¼ part of the planet is constantly warming up, and its other parts are in darkness. It has 5 satellites.
Atmosphere of pluto
It has good reflective ability. Therefore, it is probably covered in ice. The ice crust consists of nitrogen and individual methane spots. Those areas that are warmed by the sun's rays turn into a cluster of rarefied particles. That is, either Pluto’s atmosphere is icy or gaseous.
Sunlight mixes nitrogen and methane, giving the planet a mysterious bluish glow. This is how the radiance of the planet Pluto looks in the photo.
Due to its small size, Pluto is not able to maintain a dense atmosphere. Pluto loses it very quickly - a few tons in an hour. It is surprising that so far has not lost it all in the open spaces. Where Pluto takes nitrogen to form a new atmosphere is not yet clear. Perhaps it is present in the bowels of the planet and seasonally breaks out on its surface.
Composition of Pluto
What is inside, scientists conclude on the basis of data obtained over the years of studying the planet.
The calculation of the density of Pluto led scientists to assume that 50-70% of the planet is made up of stone. Everything else is ice. But if the core of the planet is rocky, it means that a sufficient amount of heat must be present inside it. It was she who divided Pluto into a rocky base and an ice surface.
Temperature on Pluto
Pluto was once considered the coldest planet in our solar system. Due to the fact that it is very far from the Sun, the temperature here can drop to -218 and even to -240 degrees Celsius. The average temperature is - 228 degrees Celsius.
At a point close to the Sun, the planet warms up so much that the nitrogen frozen in the atmosphere, which is present in the atmosphere, begins to evaporate. The transition of a substance from a solid state to a gaseous state is called sublimation. Evaporating, it forms diffuse clouds. They freeze and fall to the surface of the planet in the form of snow.
Satellites of Pluto
The largest satellite of Pluto is Charon. This celestial body is also of great interest to scientists. It is located at a distance of 20,000 km from Pluto. It is noteworthy that they resemble a single system consisting of two cosmic bodies. But at the same time they were educated independently of each other.
Since the Charon-Pluto pair moves in unison, the satellite never changes its location (when viewed from Pluto). It is connected with Pluto by tidal forces. It takes 6 days and 9 hours to go around the planet.
Most likely, Charon is an icy analogue of the moons of Jupiter. Its surface, created from water ice, gives it a gray color.
Having modeled the planet and its satellite on a supercomputer, scientists came to the conclusion that Charon spends most of his time between Pluto and the Sun. The ice melts on the surface of Charon from solar heat and a rarefied atmosphere forms. But why has the ice on Charon still not disappeared? It is likely fed by satellite cryovolcanoes. Then it “hides” in the shadow of Pluto, and its atmosphere freezes again.
In addition, during the study of Pluto, 4 more satellites were discovered - Nikta (39.6 km), Hydra (45.4 km), Styx (24.8 km) and Kerber (6.8 km). The dimensions of the last two satellites may be inaccurate. The lack of brightness makes it difficult to determine the mass and diameter of the cosmic body. Previously, scientists were confident in their spherical shape, but today they assume that they have the shape of ellipsoids (that is, the shape of an elongated sphere).
Each of the tiny satellites is unique in its own way. Nyx and Hydra reflect light well (about 40%), just like Charon. Kerber is the darkest of all satellites. Hydra - completely formed from ice.
Exploring Pluto
In 2006, NASA launched a spacecraft, which allowed a more detailed study of the surface of Pluto. It received the name "New Horizons". In 2015, after 9.5 years, he finally met with a dwarf planet. The device approached the object of study at a minimum distance of 12,500 km.
The exact images sent by the device to Earth told much more than the most powerful telescopes. After all, it is too small for being well visible from the Earth. I managed to discover many interesting facts about the planet Pluto.
Scientists from around the world note that the surface of Pluto is incredibly interesting. There are many craters, icy mountains, plains, ominous tunnels.
sunny wind
It turns out that the space baby possess unique properties that other planets of the solar system are deprived of. They consist in its interaction with the solar wind (thereby causing magnetic storms). Comets cut through the solar wind, and the planets literally hit it. Pluto exhibits both types of behavior. This makes it look more like a comet than a planet. In this scenario, the so-called plutopause is formed. It is characterized by the formation of a vast area in which the speed of the solar wind is gradually increasing. Wind speed is 1.6 million km / h.
A similar interaction formed in Pluto the tail observed in comets. The ion tail consists mainly of methane and other particles that make up the planet’s atmosphere.
Pluto Spider
The frozen surface of Pluto should look dead, scientists are sure. That is dotted with craters and cracks. Most of its surface looks exactly like that, but there is an area that seems surprisingly smooth. Probably, it was influenced by something located in the inner layers of the planet.
And one of the areas covered with cracks resembles a spider with six legs. Scientists have never seen such a thing. Some legs are up to 100 km long, others are longer. And the length of the largest "paws" is 580 km. Surprisingly, these points have one base, and the depths of cracks are highlighted in reddish color. What is it? Perhaps this indicates the presence of some kind of underground material.
"Heart" of Pluto
There is the so-called Tombo region on the planet, which has ... a heart shape. This region has a smooth surface. It is probably relatively young and the geological processes on it took place not so long ago.
In 2016, scientists explained in detail how the Tombo region appeared on the planet. It was probably due to a combination of two factors - atmospheric processes and geological features. Deep craters accelerate the solidification of nitrogen, which, together with carbon monoxide, covers an area more than a thousand kilometers long and goes 4 km deep into Pluto. Perhaps in the coming decades, most of the glaciers on the planet will disappear.
Another mystery of Pluto
On Earth, in the highlands of the tropics and subtropics, snow pyramids are found. Previously, scientists believed that this phenomenon is found only on the surface of the Earth. They are called "penitent snows," because they resemble figures with a bowed head. However, such formations on our planet reach a maximum of 5-6 meters in height. But the surface of Pluto was cut up by these figures, whose height is up to 500 km. These needle shapes are formed from methane ice.
As scientists explain, there are climate variations on Pluto. They believe that the process of formation of methane needles coincides with the processes occurring on the planet. How are our "penitent snows" formed?
The sun illuminates the ice at a large angle, one part of it melts, and the other remains untouched. A kind of "hole" is formed. They do not reflect light and heat into the atmosphere, but, on the contrary, retain them. Thus, the process of ice melting begins to intensify sharply. This causes the formation of structures similar to peaks and pyramids.
Something similar happens on Pluto. These needles lie on top of even larger ice formations and are probably echoes of the ice age. Our analogues, according to our experts, are not in the Solar system.
This mountain valley, called Tartar, is adjacent to another object of interest to scientists - the Tombo Valley, which is described above.
Ocean on Pluto?
Scientists believe that the oceans in our solar system are quite common. But can there be an ocean under a frozen layer of the surface of a dwarf planet? It turns out that this is quite possible.
The western part of the Tombo region looks rather strange in comparison with the rest of the surface of Pluto. The size in km of it is about 1000. The region is called "Sputnik Planika". Its surface is characterized by a smooth, relatively fresh ice crust and the absence of impact craters. Perhaps this ancient basin is a crater whose heat seeps from the inside and makes the ice melt, as if updating it.
It is noteworthy that the "Sputnik Platinum" is heavier than its environment. Scientists attribute this to the presence of a subsurface ocean. The Nimmo team is dealing with this issue. Probably, the Pluto ocean is located at a depth of 100 kilometers and contains a large percentage of liquid ammonia. His age may amount to billions of years. If the ocean were not hidden by a strong crust of ice, life could have arisen in it. In any case, it is not possible to find and explore it in the next hundreds of years.
Methane snow
The New Horizons device presented scientists with detailed, incredibly interesting pictures. In the images you can see the plains and mountains. One of the largest mountains in Pluto is the unofficial name of Cthulhu Regio. It extends for almost 3,000 km. The size of the planet Pluto is so small that the mountain range almost completely encircles it.
From the height of the New Horizons apparatus, the mountains resemble an accumulation of pits, craters, and dark areas. Methane light covers this mountain range. It is seen as a bright spot against the background of lowlands with a red tint. Most likely, snow is formed here on the same principle as on Earth.
Conclusion
The New Horizons apparatus became a researcher who met with Pluto. He told about this mysterious planet many interesting, previously unknown to us facts about the ice baby. Research is ongoing, and scientists may soon learn more about this planet.
Today we discussed the facts known to us at the moment. We compared the size of Pluto with the Moon, Earth and other cosmic bodies of our solar system. The research process raises many questions to which scientists have no answers yet.