What is the solar system. Distant planets The farthest planet from earth in the solar system

On March 13, 1781, English astronomer William Herschel discovered the seventh planet in the solar system - Uranus. And on March 13, 1930, American astronomer Clyde Tombaugh discovered the ninth planet in the solar system - Pluto. By the beginning of the 21st century, it was believed that the solar system included nine planets. However, in 2006, the International Astronomical Union decided to strip Pluto of this status.

There are already 60 known natural satellites of Saturn, most of which have been discovered using spacecraft. Most satellites are made up of rocks and ice. The largest satellite, Titan, discovered in 1655 by Christian Huygens, is larger than the planet Mercury. The diameter of Titan is about 5200 km. Titan orbits Saturn every 16 days. Titan is the only satellite to have a very dense atmosphere, 1.5 times the size of Earth's, and consisting mostly of 90% nitrogen, with a moderate amount of methane.

The International Astronomical Union officially recognized Pluto as a planet in May 1930. At that moment, it was assumed that its mass was comparable to the mass of the Earth, but later it was found that the mass of Pluto is almost 500 times less than the Earth's, even less than the mass of the Moon. The mass of Pluto is 1.2 times 1022 kg (0.22 Earth masses). The average distance of Pluto from the Sun is 39.44 AU. (5.9 by 10 to the 12th degree km), the radius is about 1.65 thousand km. The period of revolution around the Sun is 248.6 years, the period of rotation around its axis is 6.4 days. The composition of Pluto supposedly includes rock and ice; the planet has a thin atmosphere composed of nitrogen, methane and carbon monoxide. Pluto has three moons: Charon, Hydra and Nyx.

In the late 20th and early 21st centuries, many objects were discovered in the outer solar system. It has become clear that Pluto is only one of the largest Kuiper belt objects known to date. Moreover, at least one of the objects of the belt - Eris - is a larger body than Pluto and 27% heavier than it. In this regard, the idea arose to no longer consider Pluto as a planet. On August 24, 2006, at the XXVI General Assembly of the International Astronomical Union (IAU), it was decided to henceforth call Pluto not a "planet", but a "dwarf planet".

At the conference, a new definition of the planet was developed, according to which planets are considered to be bodies revolving around a star (and not being a star themselves), having a hydrostatic equilibrium shape and "clearing" the area in the region of their orbit from other, smaller, objects. Dwarf planets will be considered objects that revolve around a star, have a hydrostatically equilibrium shape, but have not "cleared" the nearby space and are not satellites. Planets and dwarf planets are two different classes of solar system objects. All other objects revolving around the Sun and not being satellites will be called small bodies of the solar system.

Thus, since 2006, there have been eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Five dwarf planets are officially recognized by the International Astronomical Union: Ceres, Pluto, Haumea, Makemake, and Eris.

On June 11, 2008, the IAU announced the introduction of the concept of "plutoid". It was decided to call plutoids celestial bodies that revolve around the Sun in an orbit whose radius is greater than the radius of Neptune's orbit, whose mass is sufficient for gravitational forces to give them an almost spherical shape, and which do not clear the space around their orbit (that is, many small objects revolve around them ).

Since it is still difficult to determine the shape and thus the relation to the class of dwarf planets for such distant objects as plutoids, scientists recommended temporarily assigning to plutoids all objects whose absolute asteroid magnitude (brilliance from a distance of one astronomical unit) is brighter than +1. If it later turns out that the object assigned to the plutoids is not a dwarf planet, it will be deprived of this status, although the assigned name will be left. The dwarf planets Pluto and Eris were classified as plutoids. In July 2008, Makemake was included in this category. On September 17, 2008, Haumea was added to the list.

The material was prepared on the basis of information from open sources

Neptune is the eighth and farthest planet in the solar system. Previously, Pluto was considered the most distant. However, recently, by decision of the International Astronomical Union, it was "demoted" from the planets and became a planetoid (the so-called dwarf planet). This happened after several more similar small planets were discovered behind it, while one of them (Eris) turned out to be even larger than Pluto. Neptune is the fourth largest planet in diameter and third largest in the solar system. The mass of Neptune is 17.2 times, and the diameter of the equator is 3.9 times that of the Earth. The planet was named after the Roman god of the seas.

Neptune was the first planet to be discovered (in 1846) through mathematical calculations rather than through regular observations. This happened because unforeseen changes in the orbit gave rise to the hypothesis of an unknown planet that affects Uranus with its gravitational field. Neptune was found within the mathematically predicted position.

The average distance between Neptune and the Sun is 4.55 billion km (about 30.1 times the average distance between the Sun and the Earth, or 30.1 AU). The period of complete revolution of Neptune around the Sun is 164.79 Earth years. The period of rotation of the planet around its axis is 15 hours 8 minutes. Neptune's axial tilt is 28.32°, which is similar to the axial tilt of Earth and Mars. As a result, the planet experiences similar seasonal changes. However, due to Neptune's long orbital period, the seasons last for forty years each.

The internal structure of Neptune and its composition are close to and also very different from the gas giants - and, consisting mainly of hydrogen and helium. Therefore, astronomers sometimes place Uranus and Neptune in a separate category of "ice giants". The atmosphere makes up approximately 10-20% of the total mass of the planet, and the distance from the surface to the end of the atmosphere is 10-20% of the distance from the surface to the core. The atmosphere of Neptune, like the atmosphere of Jupiter and Saturn, consists mainly of hydrogen and helium, but contains a higher proportion of ice: water, ammonia, methane. Traces of methane in the outer atmosphere, like those of Uranus, are responsible for the planet's blue color, although Neptune's bright azure differs from Uranus's more moderate aquamarine. The core of Neptune, like Uranus, consists mainly of ice and rocks.

In the atmosphere of Neptune, the strongest winds among the planets of the solar system rage. According to some estimates, their speeds can reach supersonic speeds of 2100 km / h (about 600 m / s) (!). The weather is characterized by an extremely dynamic system of storms. Most of the winds on Neptune blow in the opposite direction of the planet's rotation on its axis. In 1989, the so-called Great Dark Spot, similar to the Great Red Spot on Jupiter, was discovered in the southern hemisphere of Neptune. The temperature of Neptune in the upper atmosphere is close to -220 °C. In the center of Neptune, the temperature is estimated to be from 5400 °K to 7000-7100 °C, which is comparable to the temperature on the surface of the Sun and comparable to the internal temperature of most known planets.

Just like other gas giants of the solar system, Neptune has a weak and fragmented ring system, reliably confirmed in 1989. Therefore, detecting it from Earth is very, very difficult. The rings may be composed of ice particles coated with silicates or a carbon-based material, most likely giving them a reddish tint.

Neptune currently has 13 known moons. The largest of these weighs more than 99.5% of the masses of all Neptune's moons combined, and is the only one massive enough to be spheroidal. This is Triton, discovered by William Lassell just 17 days after the discovery of Neptune. It is larger than the Moon in size and mass. It has a reverse direction of orbital motion. Due to tidal acceleration, Triton slowly spirals towards Neptune, and will eventually be destroyed when the Roche limit is reached, resulting in a ring that may be more powerful than Saturn's (this will happen after a relatively small, on an astronomical scale, time period: 10 to 100 million years). In 1989, Triton was considered the coldest object in the solar system to be measured, with an estimated temperature of -235°C (38°K). Triton is one of the three satellites of the planets in the solar system that have an atmosphere (along with Io and Titan).

Neptune has only been visited by one spacecraft, Voyager 2, which flew close to the planet in 1989.

Despite the fact that Neptune cannot be distinguished by its gigantic size among the planets, its mass exceeds the mass of Uranus. It is not easy to observe this planet - you can hardly see anything other than a small disk. For such an observation, a telescope is not necessary - you can simply examine this planet with binoculars. The ring of this planet from our Earth cannot be seen at all. And in general, only one space satellite called Voyager 2 had the honor of reaching such a distant land. The success of this device has not yet been repeated by anyone.

general information

Neptune is located at a distance of 30 astronomical units from the Sun, and its diameter is almost 50 thousand kilometers. In other words, this object weighs as much as 17 of our Earths! The period of rotation around the Sun is almost 165 years, and the average temperature is 55 Kelvin.

There are legends that Neptune got its name because of the color - blue. It is generally accepted that blue is associated with water in the seas and oceans. And since Neptune is the god of the sea, the planet was named after him.

Discovery of Neptune

When scientists discovered the seventh planet Uranus, they thought something was wrong on it. Its orbit did not comply with Newton's laws and was somewhat strange in its behavior. Scientists thought that the reason for this could be another, new planet, which is located behind Uranus and changes the route of its movement in orbit. Given all the information that astronomers had in their hands at that time, they calculated the approximate location of the new planet. The assumptions turned out to be correct, although no one really hoped for it, and the world saw Neptune. Computational astronomy has never reached such heights.

Composition and conditions

The chemical elements that make up the planet are very similar to the chemical elements of uranium. Both planets are covered in ice and solidified gases with small percentages of hydrogen and helium. The estimated core of Neptune is about the same mass as the Earth.

Neptune belongs to the gas planets, which means that various tornadoes, storms, wind streaks are frequent phenomena for him. The wind can reach speeds of 650 m/s! In addition to the Sun, Neptune also warms up from the inside. Moreover, this energy is more than twice the solar energy.

There are two spots on the surface of Neptune. One of them is called the Great Dark Spot, which was discovered in the southern hemisphere. The second was slightly smaller and remained unnamed.

Now nothing is known about the existence of the first, it has either evaporated, or at the moment it is at such an angle to us that we cannot see it. Researchers recently announced that a new spot has formed on Neptune. This tells us that the planet's atmosphere changes frequently and the exact reason for this is not yet known.

Non-fiction film about the outer planets

A newly discovered object could set a new record as the most distant dwarf planet in the solar system. This object, named V774104, lies fifteen billion kilometers from the Sun, two to three times as far away as Pluto. V774104 is slightly smaller than half of Pluto and, like this planet, may move closer or further away from the Sun as it orbits, but these details remain to be clarified.

“Basically, that’s all we know about her. We don't even know its orbit because we found it two weeks ago,” said Scott Sheppard of the Carnegie Institute of Science, one of the discoverers of the new object. The discovery is part of a larger hunt for objects in this cold, dark region beyond the orbit of Pluto, where scientists hope to find clues about the early solar system.

Sheppard announced the discovery at the annual meeting of the American Astronomical Society on November 10. In an interview with Space.com, he said that V774104 is certainly one of the most distant objects ever observed, although more precise data is needed to award the planet the title of the most distant dwarf planet.

In his search, Sheppard worked with Chadwick Trujillo of Gemini Hawaii and Dave Tholen of the University of Hawaii.

"We're doing the widest and deepest exploration of outer solar system objects in history," Sheppard said. - We use an 8-meter Subaru telescope in Hawaii. Just looking for things outside the Kuiper belt, beyond the orbit of Pluto."

Objects in the outer solar system are dim and rare, Sheppard says. To find them, the researchers turned to the Subaru telescope, which collects large amounts of light in a short amount of time and can scan large swaths of the sky fairly quickly, which Sheppard believes is a key combination in finding these hidden gems.

Is there life beyond Neptune

Beyond the orbit of Neptune is a group of cold, icy bodies (including Pluto) called the Kuiper belt. Pluto is 8 billion kilometers from the Sun, but when talking about the solar system, "astronomical units" are usually used (1 AU = distance from the Earth to the Sun, about 150 million kilometers). Neptune averages 30.1 AU. e. from the Sun; Pluto rotates between 29 and 49 AU. e.

If the measurements of V774104 are correct, the object is currently at 103 AU. e. from the Sun, which places it in the region of the Oort cloud. The Oort cloud is a hypothetical sphere of icy solid objects that wraps around the solar system.

The dwarf planet Eris orbits the Sun in the inner Oort cloud at a distance of 37 to 97 AU. e. The dwarf planet Sedna, discovered in 2003, has an incredibly eccentric orbit, meaning it could be anywhere between 76 and 940 AU. e. from the Sun. Last year Sheppard and Trujillo like Sedna, 2012 VP113, whose orbit lies between 80 and 452 AU. e. from the Sun.

(Astronomers also know about long-period comets that hail from the outer Oort cloud, meaning they reach distances of 5,000 to 100,000 AU from the Sun, Sheppard says. These long-period comets are considered "the most distant objects in the solar system," though they don't its entire life in the outer regions (none of these long-period comets come close to being a dwarf planet or a minor planet).

quiet orbit

Sedna and VP113 are far enough from the inner solar system (Earth's closest neighborhood) to not be affected by the gravity of the system's eight planets, according to Sheppard.

"Sedna and VP113 are the only objects that are completely separated from the giant planetary region," Sheppard says. “And yet they have very elongated orbits, so we find them very interesting. As far as their orbits are concerned, as far as we know the solar system, they shouldn't be bothered at all. They shouldn't have formed in those orbits at all. Something disturbed them."

So Sheppard and Trujillo are looking into the far solar system. They are looking for objects that have been untouched since the early days of the solar system, which means they behave the same as they did after the formation of the system 4.6 billion years ago. Sheppard says the leading theory about the formation of the solar system is that the Sun was born "in a very dense stellar environment, when a handful of stars appeared near it." The gravitational pull of these stars could perturb objects like Sedna.

Again, it is possible that there is a massive and as yet unknown object outside of Pluto's orbit that is responsible for the gravitational perturbation of objects in the inner Oort cloud.

“Some of the objects in the inner Oort cloud can compete in size with Mars or even Earth,” Sheppard said. "That's because many of the objects in the inner Oort cloud are so far away that even the largest ones would be so dim that they would be undetectable with current technology."

The answer can be found in the process of studying the objects of this outer region.

"We want to find a scattering of objects like VP113, which we found last year," Sheppard says. - There are several different theories about how these distant objects could have come to their eccentric orbits. All of these different theories predict different orbital distributions and populations. If we find 10 such objects or so, we can begin to determine which theories for the formation of such objects are correct.”

This illustration clearly shows the size of the exoplanet Kepler-452b compared to the Earth. Kepler-452b is 60% larger than Earth and lies 1400 light-years away in the constellation Cygnus.

This image by a NASA artist shows the exoplanet Kepler-186f, another contender for our Earth's twin. This planet was discovered in October 2014. And it probably has liquid water on it. Because The planet is in the habitable zone of its Sun. This planet is located at a distance of 500 light years from earth, also in the constellation Cygnus.

3. Sedna.

This object was discovered by astronomers well beyond the orbit of Pluto beyond the Kuiper belt. This illustration was submitted by an artist from NASA on March 26, 2014. A massive icy celestial body can reveal what the solar system was like at an early stage of its existence.

Ceres. In the asteroid belt between Mars and Jupiter. The most intriguing object in the solar system. Icy, spewing water vapor from its icy surface into outer space. Scientists argue whether such conditions can be hospitable to any life forms.

An artist's view of views from the surface of the super-Earth Gliese 667 Cc. A billion such worlds revolve around their red dwarfs in our galaxy.

View of planets the size of our Saturn orbiting the star 79 Centauri

An artist's view of a planet larger than the Earth, the super-Earth Kepler-62e, whose orbit is in the habitable zone of a star smaller and colder than the Sun. Super-Earth Kepler-62e is 1400 light-years away.

The moment of the birth of an icy planet near a young star named TW Hydrae. This beauty is located at a distance of 175 light years from earth in the constellation Hydra

The most Earth-like planet, Kepler-22b, circles its star. it supposedly contains water and the chemical elements necessary for the origin of life.

An object with the complex name OGLE-2005-BLG-390Lb. This newly discovered planet, located 20,000 light years away, orbits a star 5 times smaller than our Sun.

An artist's vision of a planet orbiting the star c, the member of the triple star system closest to us. Our Sun can be seen in this photo - top right in the corner.

Exoplanet HD 189733b, the size of Jupiter. "Hot Jupiter", as this planet is also called, is so close to its star that it makes one revolution around its star in just 2.2 days.

This young planet Kepler-37b is slightly larger than the Moon, according to scientists, its surface temperature reaches 400 degrees Celsius, this small planet has an atmosphere and possibly some life forms. Its complete revolution around its star takes only 13 days.

The planet, made up mostly of diamond rocks, revolves around its star in the constellation Cancer, so fast that a year on this planet lasts only 18 hours.

A star similar to the Sun has 6 planets in its orbit

Hot, rocky and geologically active planet. It has an atmosphere, it is quite possible that Venus is all wrapped in clouds.

The first photograph of the planet Fomalhaut b, which has a mass three times that of Jupiter. It is located 25 light years from Earth.

An obscure planet called HAT-P-1 has a diameter 1.38 times that of Jupiter and at the same time has only half the mass of Jupiter.

A rather old planet, 13 billion years old. The gas giant revolves around a helium white dwarf and millisecond pulsar B1620-26. A small amount of heavy elements in such globular clusters makes it difficult to create planets and therefore, most likely, the appearance of new planets was possible only at an early stage of the formation of the universe.

21. Planet 2003UB313

The most remote planet in the solar system ever discovered. It is located on the outer fringes of our solar system and its orbit is three times farther than the orbit of Pluto.

A planet the size of Jupiter passes a star. and The brightness from such a star drops by a few percent, this phenomenon is called "Transit" and this event helps scientists to know that there is a planet or planets in the orbit of the observed star.

This exoplanet has a mass six times greater than our Earth, and its orbit around its star is all 1/20 of the distance from Earth to the Sun.

The only planet known to orbit two stars, a large dwarf with 69% of the Sun's mass and a small dwarf with 20% of the Sun's mass. Life on such planets is not possible. because Its surface is very cold and, moreover, gaseous.

25. An amazing type of exoplanet

The amazing planet was discovered by the Hubble telescope. The planet is so close to its star that its year is only 10.5 hours, the distance to the star is only 750,000 miles or 1/30 of the distance from the Earth to the Sun, and it is unlikely that any life can exist on it.

The young solar system, there is as much water in it as it is enough to fill all the oceans on our planet 5 times. It is located in our Milky Way galaxy at a distance of 1000 light years.