Pluto is a planet named after 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 little studied. But in 2006, in order to study it in more detail, a device was launched, which in 2015 reached Pluto. His mission will end in 2026.
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.
Discovery of the planet
Even in the 19th century, scientists were sure that there was another planet beyond Uranus. The power of the then telescopes did not allow them to detect it. Why was Neptune so eagerly sought? The fact is that the distortions of the orbits of Uranus and Neptune could only be explained by the presence of anotherthe planet that influences it. As if "pulls" on itself.
And in 1930, Neptune was finally discovered. However, it turned out to be quite small in order to cause such perturbations of Uranus and Neptune. In addition, its axis is as tilted as the axes of Uranus and Neptune. That is, the influence of an unknown celestial body also affects it.
Scientists are still looking for the mysterious planet Nibiru, wandering through our solar system. Some are sure that it can soon cause an ice age on Earth. However, its existence has not yet been confirmed. Although its description, the researchers suggest, is in the ancient Sumerian texts. But even if the killer planet really exists, we should not fear 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 Arizona by Clyde Tombaugh. The search for the so-called planet-X has been going on since 1905, but only a team of American scientists managed to make this discovery.
The question arose of what name to give to the discovered planet. And it was proposed to call it Pluto by an eleven-year-old schoolgirl Venetia Burney. Her grandfather found out 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 the ancient Roman version of the name of the god of the underworld, Hades. Venice explained her logic very simply - this name harmonized perfectly with the silent and cold cosmicbody.
The size of the planet Pluto (in kilometers - even more so) remained unspecified for a long time. In the telescopes of those times, the ice baby was seen only as a bright star in the sky. It was completely impossible to determine its mass and diameter. Is it larger than the earth? Perhaps even larger than Saturn? Questions tormented scientists until 1978. It was then that the largest satellite of this planet, Charon, was discovered.
How big is Pluto?
And it was the discovery of its largest moon that helped establish Pluto's mass. They named him Charon, in honor of the otherworldly creature that transports the souls of the dead to the underworld. Charon's mass was known quite accurately back 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 draw a conclusion about their sizes. But these are only approximate figures. The exact size 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 × 1022 kg, and the volume is 6.39 109 km³. Length - 2370.
For comparison, the diameter of Eris, the largest dwarf planet in our solar system, is 1,600 miles. Therefore, it is not surprising that Pluto was given the status of a dwarf planet in 2006.
That is, it is the tenth heaviest object in the solar system and the second among the dwarf planets.
Pluto and Mercury
Mercury is closest toSun planet. He is the exact opposite of an ice kid. 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 the two "babies" also differs. 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 in its composition. It is inferior to Mercury in terms of gravity. If you were lucky enough to visit a dwarf planet, every step you take would take you off its surface.
When in 2006 Pluto was no longer considered a full-fledged planet, the title of space baby again went to Mercury. And the title of the coldest was given to Neptune.
The dwarf planet is also smaller than our solar system's two largest moons, 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 the density is 60% of the earth's and is second only to Saturn's satellite Io among the celestial bodies of our solar system.
How much smaller is Pluto than Earth? Comparing the sizes of Pluto and the Earth clearly shows how small it is. It turns out insideour planet would fit 170 "Plutons". NASA even provided a graphical image of Neptune in the background of the Earth. It is impossible to explain better how much their masses differ.
The size 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 16,650,000 km². Comparing the size of Pluto and Russia in human terms makes the planet quite insignificant. Is Pluto a planet at all?
Scientists are sure that a celestial body that has a clean space can be considered a planet. That is, the gravitational field of the planet must either absorb the nearest space objects or throw them out of the system. But Pluto's mass 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 adding Pluto to the list of dwarf planets was another fact - in the Kuiper belt, where the space baby is also localized, 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 essence, scientists, ranking Pluto among the nine planets of the solar system, understood that it was a matter of time. One day the cosmos goes further than Pluto, and there are bound to be larger cosmic bodies. And calling Pluto a planet would be incorrect.
Pluto is formally called a dwarf planet. But in fact, full-fledged planets under thisare not included in the classification. This term was introduced in the same year 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 an exact definition.
But despite the loss of status, the ice baby remains an interesting and important subject for study. Having considered how big Pluto is, let's move on to other interesting facts about it.
Pluto Key Features
The planet is located at the very border 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 inclination to the plane of the ecliptic. Due to this, Pluto can approach the Sun closer than Neptune. Therefore, from 1979 to 1998, Neptune remained the most distant planet from the heavenly body.
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 of the planet is constantly warming up, while other parts of it are in darkness. Has 5 satellites.
Pluto's atmosphere
It has good reflective ability. Therefore, it is probably covered in ice. The ice crust is composed of nitrogen and occasional patches of methane. Those areas that are warmed by the sun's rays turn into a cluster of rarefied particles. That is, either the atmosphere of Pluto is icy or gaseous.
Sunlight mixes nitrogen and methane, giving the planet a mysteriousbluish glow. This is what the glow of the planet Pluto looks like in the photo.
Due to its small size, Pluto is unable to hold a dense atmosphere. Pluto loses it very quickly - several tons within an hour. It's amazing that he still hasn't lost it all in the vastness of space. Where Pluto takes nitrogen to form a new atmosphere is still unclear. Perhaps it is present in the bowels of the planet and breaks out on its surface seasonally.
Pluto Composition
What's inside, scientists conclude based on data obtained over the years of studying the planet.
Calculation of Pluto's density led scientists to assume that 50-70% of the planet is made of rock. Everything else is ice. But if the core of the planet is rocky, then there must be a sufficient amount of heat inside it. It was it that divided Pluto into a rocky base and an icy 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 heats up so much that the frozen nitrogen present in the atmosphere begins to evaporate. The transition of a substance from a solid state directly to a gaseous state is called sublimation. Evaporating, it forms diffuse clouds. They freeze and fall to the planet's surface as snow.
Pluto's moons
Pluto's largest moon 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 formed independently of each other.
Because the Charon-Pluto pair moves in unison, the satellite never changes its location (when viewed from Pluto). It is connected to Pluto by tidal forces. It takes him 6 days and 9 hours to go around the planet.
Most likely, Charon is an icy analogue of Jupiter's moons. Its surface, made of water ice, gives it a gray color.
Having simulated 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. From the heat of the sun on the surface of Charon, ice melts and a rarefied atmosphere is formed. But why hasn't the ice on Charon disappeared yet? It is probably fed by the satellite's cryovolcanoes. It then "hides" in Pluto's shadow and its atmosphere freezes again.
In addition, during the period of studying Pluto, 4 more satellites were discovered - Nikta (39.6 km), Hydra (45.4 km), Styx (24.8 km) and Kerberos (6.8 km). The dimensions of the last two satellites may not be accurate. The lack of brightness makes it difficult to determine the mass and diameter of a cosmic body. Early scientists were sure of their spherical shape, but today they suggest that they have the shape of ellipsoids (that is, the shape of an elongated sphere).
Each oftiny satellites is unique in its own way. Nikta and Hydra reflect light well (about 40%), as does Charon. Kerberos is the darkest of all moons. Hydra - made entirely of ice.
Exploring Pluto
In 2006, NASA launched a spacecraft that allowed us to study the surface of Pluto in more detail. It was called "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.
Precise images sent by the device to Earth, told much more than the most powerful telescopes. After all, it is too small for what is well visible from the Earth. Many interesting facts about the planet Pluto have been discovered.
Scientists from all over the world say that the surface of Pluto is incredibly interesting. There are many craters, ice mountains, plains, ominous tunnels.
Solar wind
It turns out that the space baby has unique properties that other planets in the solar system lack. They lie in its interaction with the solar wind (the one that causes 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 such a scenario of the development of events, the so-called plutopause is formed. It is characterized by the formation of a vast region in which the speed of the solar wind graduallyincreases. The wind speed is 1.6 million km/h.
Such an interaction formed Pluto's tail, which is observed in comets. The ion tail is made up primarily of methane and other particles that make up the planet's atmosphere.
Pluto's Spider
The frozen surface of Pluto should look dead, scientists believe. That is, dotted with craters and cracks. Most of its surface looks exactly like this, but there is an area that seems surprisingly smooth. She was probably influenced by something in the inner layers of the planet.
And one of the cracked areas resembles a spider with six legs. Scientists have never seen anything like this. Some "legs" are up to 100 km long, others are longer. And the length of the largest "foot" is 580 km. Surprisingly, these points have the same base, and the depths of the cracks are highlighted in reddish color. What is it? Perhaps this indicates the presence of some underground material.
The Heart of Pluto
There is a so-called Tombo area on the planet, which has… the shape of a heart. This region has a smooth surface. It is probably relatively young and geological processes took place on it not so long ago.
In 2016, scientists explained in detail how the Tombo region appeared on the planet. Probably, it was caused by 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 thousandkilometers and goes deep into Pluto by 4 km. Perhaps in the coming decades, most of the glaciers on the planet will disappear.
Another Pluto mystery
On Earth, in the highlands of the tropics and subtropics, there are snow pyramids. Previously, scientists believed that this phenomenon occurs only on the surface of the Earth. They are called "repentant snows", as they resemble figures with bowed heads. However, such formations on our planet reach a maximum of 5-6 meters in height. But the surface of Pluto turned out to be indented by these figures, whose height is up to 500 km. These needle-shaped figures 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 taking place on the planet. How do our "repentant snows" form?
The sun illuminates the ice at a large angle, one part of it melts, and the other remains intact. Formed a kind of "pits". They do not reflect light and heat into the atmosphere, but, on the contrary, retain them. Thus, the process of melting ice begins to sharply increase. This causes the formation of structures similar to peaks and pyramids.
Something similar is happening on Pluto. These needles lie on top of even larger ice formations, and are likely remnants of the Ice Age. According to our experts, there are no analogues in the solar system.
This mountain valley, named Tartarus, is adjacent to another object of interest of scientists - the Tombo Valley, which is described above.
The ocean on Pluto?
Scientists believe that the oceans in our solar system are quite common. But could there be an ocean beneath the frozen surface layer of a dwarf planet? It turns out that this is quite possible.
The western part of the Tombo region looks rather odd compared to the rest of Pluto's surface. Its size in km is about 1000. The region is called "Sputnik Planitia". Its surface is distinguished by a smooth, relatively fresh ice crust and the absence of impact craters. Perhaps this ancient pool is a crater whose heat seeps in and causes the ice to melt, as if renewing it.
Remarkably, Sputnik Platinia is heavier than its surroundings. Scientists explain this by the presence of a subsurface ocean. This issue is handled by the Nimmo team. Probably Pluto's ocean is at a depth of 100 kilometers and contains a large percentage of liquid ammonia. It may be billions of years old. If the ocean had not been hidden by a strong crust of ice, life could have originated 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. The images show plains and mountains. One of the largest mountains of Pluto is unofficially called Cthulhu Regio. It stretches 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 apparatus "New Horizons"mountains resemble a cluster of pits, craters, dark areas. Methane light covers this mountain range. It is seen as a bright spot against the background of the lowlands, which have a red tint. Most likely, the snow here is formed according to the same principle as on Earth.
Conclusion
The New Horizons spacecraft became the explorer that met Pluto. He told about this mysterious planet a lot of interesting, previously unknown facts about the ice baby. Research continues, and perhaps soon scientists will 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 space bodies in our solar system. In the process of research, many questions arise that scientists do not yet have answers to.
