Pluto was removed from the planets. Planet Pluto

The conference in Prague left only eight planets on the star maps, instead of the usual nine. Since 1930, when Pluto was discovered, astronomers have found at least three more objects in space that are comparable to it in size and mass - Charon, Ceres and Xena. Pluto is six times smaller than the Earth, Charon, its satellite, is ten times smaller. And Xena is bigger than Pluto. Maybe it's all the planets? Yes, and the Moon was then offended by the name "satellite" undeservedly. None of the contenders for planetary status could compare with its dimensions.

“If we say that Pluto is a planet, then we must include not one, but already at first several planets in this class. And then it should consist not of nine planets, but of 12, and a little later - 20- 30 or even hundreds of planets. Therefore, the decision is correct, both culturally correct and physically correct," says Andrey Finkelstein, director of the Institute of Applied Astronomy of the Russian Academy of Sciences.

But astrophysicists protest. If we classify objects by size and type of orbit, then any shapeless, but very large cosmic body, which revolves around the sun, also a contender for the title of the planet. A planet, say astronomers' opponents, is a sphere created by gravity.

“It’s just that the size doesn’t mean anything. If the body is loose, then even a small one can only be supported by gravity and will have round shapes. That is, a small body can be a planet,” explains Vladimir Lipunov, astrophysicist, professor at Moscow State University named after M.V. Lomonosov. The results of this conference put an end to a long-standing dispute astronomers and answered the question why Pluto is not a planet in the solar system.

Pluto has always been the least explored planet. The only one where the atmosphere appears only for a while, when the cosmic body approaches the Sun - the ice melts from the heat. But they again tighten Pluto as soon as it moves away from the star.

Kudlanov Daniil

Research work according to a plan independently compiled by the student in the form of a presentation. The work was presented at the interschool student research conference "Creativity, search, discovery" and was awarded a diploma for the best research work.

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Research paper on the topic: "Why is Pluto not a planet in the solar system?"
Completed by: student of class 3B MBOU "School No. 32" Kudlanov Daniil Head: Golovashkina I. S.
Plan
1) scientific substantiation of the problem 2) planets of the solar system 3) characteristics of Pluto 4) experiment 5) Pluto relative to other planets 6) conclusion
Scientific substantiation of the problem
Once, at a lesson in the world around me, I noticed a drawing in my textbook from my desk mate, which depicted 9 planets of the solar system. In my textbook there was the same drawing, but there were 8 of them. I became very interested. It turned out that his textbook was an old edition, and my teacher explained that Pluto was excluded from the list of planets in the solar system. I became interested in this fact and began to look for the answer to this question in additional sources of information. This is what inspired my work.
Planets of the solar system
Currently, there are 8 planets belonging to the planets of the solar system:
1. Mercury
Mercury is the closest planet to the Sun. On the surface of the planet, the temperature rises to 400 degrees Celsius. Mercury revolves around the Sun in 88 Earth days. The iron core of Mercury makes up 80% of its mass. Now it is recognized as the smallest of the planets. Mercury has no satellites.
2. Venus
Venus is the second planet from the Sun, with an orbital period of 224.7 Earth days. It passes closer to Earth than any other planet. The atmosphere, which is a dense blanket of carbon dioxide, traps the heat that comes from the sun. Venus can be observed an hour after sunset or an hour before sunrise. Venus has no satellites.
3. Earth
Earth is the third planet from the Sun, with an orbital period of 365 days. About 71% of the Earth's surface is occupied by the oceans. About 3 - 3.5 billion years ago life arose on Earth, the development of the biosphere began. The satellite of the planet is the Moon.
4. Mars
Mars is the fourth planet from the Sun, similar to Earth but smaller and colder. Has a thin atmosphere. Around the Red Planet, as Mars is also called, two small moons fly - the satellites Phobos and Deimos.
5. Jupiter
Jupiter is the fifth planet from the Sun and the largest planet in the solar system. The planet is classified as a gas giant. Unlike the four solid planets closest to the Sun, Jupiter has 67 satellites, as well as a ring 20,000 km wide, almost adjacent to the planet.
6. Saturn
Saturn is the sixth planet from the Sun and has an amazing system of rings. Due to the rapid rotation around its axis, the ball of Saturn is, as it were, flattened at the poles and inflated along the equator. Belongs to the category of gas giants. The radius of the planet's equator is more than 60 thousand km, the polar radius is 54 thousand km Saturn has 62 known satellites.
7. Uranus
Uranus is the seventh planet from the Sun. Uranus has 27 moons and a ring system. The atmosphere of Uranus is based on helium and hydrogen. At the center of Uranus is a core composed of stone and iron.
8. Neptune
Neptune is the last planet in the solar system. Its orbit intersects with the orbit of Pluto in some places. Neptune is not visible to the naked eye. It has 13 satellites (Triton, Nereid, Naiad, Thalassa, Despina, Galatea, Larissa, Proteus, Galimeda, Psamatha, Sao, Laomedia, Neso.)
Characteristics of Pluto
Pluto (134340 Pluto) is the largest dwarf planet in the solar system and the ninth largest (excluding satellites) celestial body that orbits the sun.
From the day it was discovered in 1930 until 2006, Pluto was considered the ninth planet in the solar system. In August 2006, at the General Assembly of the III department of the International Astronomical Union, he was deprived of the status of a planet.
The magnitude of Pluto averages 15.1. Pluto looks star-shaped and blurry.
Among the objects of the solar system, Pluto is smaller in size and mass, not only in comparison with other planets, it is inferior even to some of their satellites.
Pluto's atmosphere is a thin shell of nitrogen, methane, and carbon monoxide evaporating from surface ice.
The temperature of Pluto's atmosphere is much higher than the temperature of its surface and is equal to -180 ° C.
There are five known natural satellites of Pluto, three of which have names today: Charon, discovered in 1978 by astronomer James Christie, and two small satellites, Nix and Hydra, discovered in 2005. The fourth satellite was discovered using the Hubble telescope; the announcement of the discovery was published on July 20, 2011 on the telescope's website. Temporarily named S/2011 P 1 (P4); its dimensions range from 13 to 34 km. On July 11, 2012, the discovery of the fifth moon of Pluto was announced.
Experiment
I assumed that Pluto was excluded from the list of planets in the solar system, since it is smaller in size. In this regard, I decided to conduct an experiment and try to represent all these planets according to their sizes. To do this, I molded all the planets from plasticine and compared them. Here are the results:
After noticing that Pluto is not so different from some planets (like Mercury), I realized that size is not the reason why it is no longer a planet in the solar system. It turned out that my assumptions were wrong, so I need to look for other reasons, but how Pluto differs from other planets. To do this, I compiled a visual table with the characteristics of all the planets. I will try to compare them and find differences.
Pluto compared to other planets
Composition of the atmosphere
Surface area
Equator radius
Weight
Mercury
42% oxygen, 29% sodium, 22% hydrogen, 6% helium, 0.5% potassium 0.5% (water, nitrogen, argon, etc.)
88 earth days
7.48 107 km²
2439.7 km
3.33022 1023 kg
Venus
96.5% carbon dioxide, 3.5% nitrogen
224.7 Earth days
4.60 108 km²
6051 km
48.685 1023 kg
Earth
78.08% nitrogen, 20.95 oxygen, 0.93 argon, 0.039 carbon dioxide, about 1% water vapor
365 earth days
510,072,000 km²148 940,000 km² land (29.2%)361 132,000 km² water (70.8%)
6378.1 km
59.736 1023 kg
Mars
95.32 carbon dioxide, 2.7 nitrogen, 1.6 argon, 0.38% (oxygen, carbon monoxide, etc.)
687 Earth days
144 371 391 km²
3396.2 km
6.4185 1023 kg
Composition of the atmosphere
Period of revolution around the sun
Surface area
Equator radius
Weight
Jupiter
89% hydrogen, 10% helium, 1% (methane, water, ethane, etc.)
11.86 Earth years
6.21796 1010 km²
71492 km
18986 1023 kg
Saturn
96% hydrogen, 3% helium, 1% (methane, ammonia, etc.)
29.46 Earth years
4.27 1010 km²
60270 km
5684.6 1023 kg
Uranus
83% hydrogen, 15% helium, 2% methane
84 earth years
8.1156 109 km²
25559 km
868.32 1023
Neptune
80% hydrogen, 18% helium, 1.5% methane, 0.5% (ethane, hydrogen deuteride)
164.491 Earth years
7.6408 109 km²
24764 km
1024.3 1023 kg
Pluto
99% nitrogen, 0.1 methane, 0.99% carbon monoxide
247.69 Earth years
1.795 107 km²
1195 km
0.1305 1023 kg
The table shows: each planet has its own composition of the atmosphere, the farther the planet, the longer the time of its revolution around the Sun, the surface area and radius of the equator for each planet are also different, but it is worth noting that Pluto has the smallest data. And the most important indicator is the mass of Pluto is very different from the masses of other planets. I suggested that this characteristic is the reason that Pluto is no longer a planet. In order to make sure of this, I decided to study in more detail the data by which any celestial body can count as a planet. In one of the encyclopedias, I found the following criteria: 1) revolves around the Sun 2) has enough mass to achieve a hydrostatic equilibrium shape due to its own gravity. 3) dominates its orbit
I turned out to be right. Pluto does not have enough mass to be considered a planet. “It does not meet one of the criteria for determining a planet: the mass of non-satellite objects in its orbit is too large compared to the mass of Pluto to consider that it dominates” (Encyclopedia “I Know the World”). It was for this reason that he was assigned to the dwarf planets of our solar system.
Output
Bibliography:
1. Big series of knowledge. Universe / Team of authors. - M: LLC "World of Books", 2004.2. "Universe" series Life of the Planet Nicholson Yang. - LLC "ROSMEN-IZDAT", 1999.3. "Universe": Popular scientific publication for children / Galpershtein L.Ya-M: LLC "Publishing house" Rosmen-Press ", 2002.4. "Planets" - Alexander Volkov, Vladimir Surdin - M: SLOVO, 2000.5. "Planet Earth" / Comp. A.M. Berlyant: - M: LLC "World of Books", 2004.6. Encyclopedia for children. Volume 8. Astronomy - Avanta+, 2004.7. I know the world. Space / Gontaruk T.I. - M.: AST, Keeper, 2008. 8. ru.wikipedia.org/wiki9. ugorka.ivakorin.ru/planeta%20Zemlya.html

Against the backdrop of media hype caused by the American spacecraft "New Horizons", we invite you to recall the history of Pluto, as well as to understand the reasons why it was excluded from the list of planets.

History of Pluto

At the end of XIX - beginning of XX century. astronomers from all over the world hunted for the planet, which was conventionally called "Planet X". She, judging by the studies, was further than Neptune and had a significant impact on its orbit. In 1930, Clyde Tombaugh, an explorer at the Lowell Observatory in Arizona, claimed that he had finally found this planet. The discovery was made based on images of the night sky taken at intervals of two weeks, which made it possible to track changes in the location of objects. The right to name the new celestial body belonged to the Lowell Observatory, and the choice fell on the option proposed by an 11-year-old schoolgirl from England. Venice Burney, that was the name of the girl, suggested naming the planet " Pluto”, in honor of the Roman god of the underworld. In her opinion, such a name very well suited such a distant, dark and cold planet.

Pluto diameter, according to the latest data, is 2370 km, and the mass is 1022 kg. By cosmic standards, this is a tiny planet: pluto volume 3 times smaller than the volume of the moon, and weight and does 5 times inferior to the moon. Wherein pluto area is 16.647.940 km2, which is approximately equal to the area of ​​Russia (17.125.407 km2).

Kuiper belt

When scientists discovered Pluto, they believed that there was nothing else beyond the orbit of Neptune. However, a few decades later, the researchers completely changed their minds. Thanks to powerful new telescopes, scientists have discovered that unlike other planets in our solar system, Pluto is surrounded by many other objects along its entire orbit, each with a diameter of more than 100 km, and similar in composition to Pluto itself. The accumulation of these objects began to be called Kuiper Belt. This region extends from the orbit of Neptune to a distance of 55 AU. (astronomical units) from the Sun (1 AU is equal to the distance from the Earth to the Sun).

Why Pluto is not a planet in the solar system

The Kuiper belt wasn't a problem until scientists began to discover larger and larger objects in it that were comparable in size to Pluto itself.

2005 was rich in discoveries. In January 2005 scientists discovered Eridu. This planet not only had its own satellite, but until July 2015 was considered bigger than Pluto. In the same year, scientists discovered 2 more planets - Makemake And Haumea, whose dimensions are also comparable to Pluto.

Thus, with 3 new planets (one of which was considered larger than Pluto), scientists had to make a serious decision: either increase the number of planets in the solar system to 12, or revise the criteria for classifying planets. As a result, on August 24, 2006, the participants of the XXVI General Assembly of the International Astronomical Union decided to change definition of the term "planet". Now, for an object in the solar system to be officially called a planet, it must meet all of the following conditions:

Orbit around the sun;
not be a satellite of another planet;
have sufficient mass to take a shape close to a ball under the influence of their own gravitational forces (in other words, to be round);
the force of gravity to clear the neighborhood of its orbit from other objects.

Neither Pluto nor Eris meet the latter condition, and therefore are not considered planets. But what does it mean to "clear the orbit of other objects?".

Everything is very simple. Each of the 8 planets of the solar system is the dominant gravitational body in its orbit. This means that when interacting with other, smaller objects, the planet either absorbs them or pushes them away with its gravity.

If we consider the situation on the example of our planet, then the mass of the Earth is 1.7 million times larger than all other bodies in its orbit. For comparison, the mass of Pluto is only 0.07 of the mass of all objects in its orbit, and this is absolutely not enough to clear the planet's surroundings from asteroids and other bodies.

For planets that cannot clear an orbit, scientists have introduced a new definition - "dwarf planets". Pluto, Eris, Makemake and many other relatively large objects of our solar system fall under this classification.

Pluto exploration. Results from New Horizons.

Due to its remoteness and small mass, Pluto has long been one of the least explored planets in our solar system. In January 2006, NASA launched an automatic interplanetary vehicle into space. "New Horizons", whose main mission was to study Pluto and its moon Charon.

The surface of the "heart of Pluto"

In July 2015, after 9 and a half years "New Horizons" reached the orbit of Pluto and began to transmit the first data. Thanks to the clear images taken by the station, scientists were able to make several important discoveries:

1. Pluto is bigger than we thought. The diameter of Pluto is 2.370 km, which means that it is still larger than Eris, whose diameter is 2.325 km. Despite this, the mass of Eris is still considered to be 27% more than the mass of Pluto.
2. Pluto reddish brown. This color is due to the interaction of methane molecules in Pluto's atmosphere and a specific type of ultraviolet light emitted by both the Sun and distant galaxies.
3. Pluto has a heart and ice mountains. Flying over the planet, New Horizons photographed a huge bright area in the form of a heart. As the more detailed pictures show, "Heart of Pluto", later called the Tombo region, is an area covered with ice mountains that reach a height of 3,400 m.
4. Snow may fall on Pluto. According to research, the glaciers on the planet are composed of methane and nitrogen, changing greatly throughout the year. Pluto makes one revolution around the Sun in 248 Earth years, significantly changing its distance from the sun. During the summer periods, as scientists suggest, glaciers melt and evaporate into the atmosphere, falling back in the form of snow in winter.
5. Pluto has an atmosphere made entirely of nitrogen. Studies show that Pluto's nitrogen atmosphere is rapidly escaping into space. Interestingly, this process is in many ways similar to what happened on Earth billions of years ago. Ridding the earth's atmosphere of nitrogen eventually led to the appearance of hydrogen and carbon dioxide, thanks to which life was born on our planet.

In August 2006, at the XXVI Assembly of the International Astronomical Union (IAU), it was decided to henceforth call Pluto not a "planet", but a planetoid, or "dwarf planet." This decision was largely due to the fact that Pluto, as it turned out, turned out to be only one of the largest objects of the Kuiper belt (a region of the solar system beyond the orbit of Neptune). Beyond Pluto, new minor planets were discovered: Haumea, Makemake and Eris, which, according to scientists, even surpassed Pluto in its size and mass! So the solar system lost its 9th planet ... And, judging by the latest discoveries in the field of space, not entirely justified!

Thought to be a larger dwarf planet than Pluto, Eris may actually be smaller than the former planet in our system in diameter (but still holds the status of the most massive for now). The new data comes from an analysis of the occultation caused by the passage of Eris between Earth and one of the distant stars.

Initial measurements showed that the diameter of Eris was approximately 3000 kilometers, later, based on data from the Spitzer space telescope, this figure was reduced to 2600 kilometers, and subsequent observations using the Hubble telescope made it possible to assert that the diameter of Eris is 2400 kilometers. Pluto's diameter is now estimated at 2,300 kilometers.

On the night of November 5, scientists watched as Eris, located in its orbit directly opposite one of the distant stars, cast a small shadow on Earth. Thanks to such a rare luck, it was possible to obtain new information about this dwarf planet, which unwittingly became the reason for the "deduction" of Pluto from the ranks of the planets. After calculating the size of the shadow and, accordingly, the size of the object, it turned out that the diameter of Eris is less than 2340 km. This was reported to the magazine "Sky & Telescope" by astronomer Bruno Sicardy.

If the preliminary calculations are correct, then scientists will face another question: "How can two space objects so similar in size differ so significantly in mass?" An analysis of the data obtained during the observation of the shadow of Eris on November 5 may also shed light on the question of the presence of an atmosphere on Eris.

> > Why Pluto is no longer a planet

How Pluto Became a Dwarf Planet- description for children: discovery of Pluto, in which year it ceased to be a planet, criteria, lack of mass, New Horizons.

Let's talk about why Pluto is no longer a planet in a language accessible to children. This information will be useful to children and their parents.

Even for the little ones It's no secret that Pluto was once considered the smallest and most distant planet in our system. It was discovered by American astronomer Clyde Tombaugh in 1930. It is 5.8 billion kilometers from the Sun and takes 248 years to orbit. Parents or teachers at school should explain to children that if the rest revolve around our star in an elliptical orbit, then Pluto has an incredibly strange one. Sometimes it comes closer than . So that you understand its tinyness - it is smaller than the earth's moon.

Begin explanation for children follows from the fact that Pluto has found its permanent place in the Kuiper belt. This is the part of the solar system inhabited by asteroids (filled with stone, metal and ice).

Many children, and their parents, may not know that the name of the planet was given by an 11-year-old girl in honor of the mythical guardian of the underworld. It has three moons: Nyx, Charon and Hydra. Charon is about half the size of the planet, but the other two are quite tiny.

Although at first Pluto was classified as a planet, it was later downgraded to the "dwarf" category. In 2005, astronomer Mike Brown thought he had stumbled upon a planet larger than . She was counted tenth and named Eris.

However, it should explain to children that this is what led the International Astronomical Union to reconsider the concept of "planet" and amend it. In 2006, the main criteria appeared:

• revolves around the sun;
• massive enough to create the shape of a sphere and have its own gravity;
• cleared the space around its orbit (next to it there should be no other objects that do not fall under the influence);

Eris failed this test and, to everyone's surprise, Pluto did too! He failed on the last point.

Also in 2006, NASA sent the New Horizons mission to Pluto. The ship was supposed to reach the edge of the solar system in 9 years. And he succeeded! Astronomers think there are thousands more dwarf planets in our system, but they are too far away. They hope to better study the Kuiper belt and discover new objects. Now you know why Pluto is no longer a planet. Use our photos, videos, drawings and online motion models to better understand the appearance of the dwarf planet and its surface features.