In January 2016, scientists announced that there might be another planet in the solar system. Many astronomers are looking for it, studies so far lead to ambiguous conclusions. Nevertheless, the discoverers of Planet X are confident in its existence. talks about the latest results of work in this direction.

On the possible detection of Planet X beyond the orbit of Pluto, astronomers and Konstantin Batygin from the California Institute of Technology (USA). Ninth planet solar system, if it exists, is about 10 times heavier than the Earth, and in its properties resembles Neptune - a gas giant, the most distant known planet revolving around our star.

According to the authors, the period of revolution of Planet X around the Sun is 15 thousand years, its orbit is highly elongated and inclined relative to the plane of the earth's orbit. The maximum distance from the Sun of Planet X is estimated at 600-1200 astronomical units, which brings its orbit beyond the Kuiper belt, in which Pluto is located. The origin of Planet X is unknown, but Brown and Batygin believe that this cosmic object was knocked out of a protoplanetary disk near the Sun 4.5 billion years ago.

Astronomers discovered this planet theoretically by analyzing the gravitational perturbation it exerts on other celestial bodies in the Kuiper belt - the trajectories of six large trans-Neptunian objects (that is, located beyond the orbit of Neptune) turned out to be combined into one cluster (with similar perihelion arguments, ascending node longitude and inclination). Brown and Batygin initially estimated the probability of error in their calculations at 0.007 percent.

Where exactly is Planet X - it is not known what part of the celestial sphere should be tracked by telescopes - it is not clear. The celestial body is located so far from the Sun that it is extremely difficult to notice its radiation with modern means. And the evidence for the existence of Planet X, based on its gravitational influence on celestial bodies in the Kuiper belt, is only circumstantial.

Video: caltech / YouTube

In June 2017, astronomers from Canada, the UK, Taiwan, Slovakia, the US, and France searched for Planet X using the Outer Solar System Origins Survey (OSSOS) catalog of trans-Neptunian objects. The elements of the orbit of eight trans-Neptunian objects were studied, the movement of which Planet X would have to influence - the objects would be grouped in a certain way (clustered) according to their inclinations. Among the eight objects, four are considered for the first time, all of them are more than 250 astronomical units away from the Sun. It turned out that the parameters of one object, 2015 GT50, do not fit into the clustering, which cast doubt on the existence of Planet X.

However, the discoverers of Planet X believe that the 2015 GT50 does not contradict their calculations. As Batygin noted, numerical modeling of the dynamics of the solar system, including Planet X, shows that outside the semi-major axis of 250 astronomical units, there should be two clusters of celestial bodies whose orbits are aligned by Planet X: one is stable, the second is metastable. Although the 2015 GT50 object is not included in any of these clusters, it is still reproduced by the simulation.

Batygin believes that there may be several such objects. Probably, the position of the minor semiaxis of Planet X is connected with them. The astronomer emphasizes that since the publication of data on Planet X, not six, but 13 trans-Neptunian objects indicate its existence, of which 10 celestial bodies belong to a stable cluster.

While some astronomers doubt Planet X, others are finding new evidence in its favor. Spanish scientists Carlos and Raul de la Fuente Marcos investigated the parameters of the orbits of comets and asteroids in the Kuiper belt. The detected anomalies in the movement of objects (correlations between the longitude of the ascending node and inclination) are easily explained, according to the authors, by the presence of a massive body in the solar system, the semi-major axis of the orbit of which is 300-400 astronomical units.

Moreover, in the solar system there may be not nine, but ten planets. Recently, astronomers from the University of Arizona (USA) discovered another celestial body in the Kuiper belt, with dimensions and mass close to Mars. Calculations show that the hypothetical tenth planet is at a distance of 50 astronomical units from the star, and its orbit is inclined to the ecliptic plane by eight degrees. The celestial body perturbs known objects from the Kuiper belt and, most likely, was closer to the Sun in ancient times. Experts note that the observed effects are not explained by the influence of Planet X, located much further than the "second Mars".

Currently, about two thousand trans-Neptunian objects are known. With the introduction of new observatories, in particular LSST (Large Synoptic Survey Telescope) and JWST (James Webb Space Telescope), scientists plan to bring the number of known objects in the Kuiper belt and beyond to 40,000. This will allow not only to determine the exact parameters of the trajectories of trans-Neptunian objects and, as a result, indirectly prove (or disprove) the existence of Planet X and the “second Mars”, but also directly detect them.

The science

Astronomers have discovered new small planet at the edge of the solar system and claim that another larger planet lurks even further away.

In another study, a team of scientists found an asteroid with its ring system similar to the rings of Saturn.

dwarf planets

New dwarf planet has yet to be named 2012 VP113, and its solar orbit is far beyond the known edge of the solar system.

Its distant position indicates a gravitational the influence of another larger planet, possibly 10 times the size of Earth and which is yet to be discovered.

Three photographs of the discovered dwarf planet 2012 VP113 taken 2 hours apart on November 5, 2012.

It was previously thought that there was only one small planet in this distant part of the solar system. Sedna.

The orbit of Sedna is at a distance that is 76 times the distance from the Earth to the Sun, and the nearest 2012 VP113's orbit is 80 times the Earth-Sun distance or is 12 billion kilometers.

Orbit of Sedna and dwarf planet 2012 VP113. The orbits of the giant planets are also shown in magenta. The Kuiper belt is marked with blue dots.

Researchers used a DECam camera in the Andes of Chile to discover 2012 VP113. Using the Magellan telescope, they established its orbit and obtained information about its surface.

Oort cloud

Dwarf planet Sedna.

The diameter of the new planet is 450 km compared to 1000 km at Sedna. It may be part of the Oort Cloud, a region that exists outside the Kuiper Belt, a belt of icy asteroids that orbit even further than the planet Neptune.

Scientists intend to continue searching for distant objects in the Oort Cloud, as they can reveal a lot about how the solar system formed and developed.

They also believe that the size of some of them may be larger than Mars or Earth, but because they are so far away, they are difficult to detect with current technology.

New asteroid in 2014

Another team of researchers found an icy asteroid surrounded by a double ring system, similar to the rings of Saturn. Only three planets: Jupiter, Neptune and Uranus have rings.

The width of the rings around the 250-kilometer asteroid Chariklo is 7 and 3 kilometers respectively, and the distance between them is 8 km. They were discovered by telescopes from seven places in South America, including the European Southern Observatory in Chile.

Scientists cannot explain the presence of rings in the asteroid. They may be composed of rocks and ice particles formed from a past asteroid impact.

Perhaps the asteroid is in a similar evolutionary stage as the Earth early period, after an object the size of Mars collided with it and formed a ring of debris that coalesced into the Moon.

Most of the planets in the solar system were discovered in ancient times. Since then, they have been observed regularly. Mercury, Venus, Mars, Jupiter and Saturn are visible to the naked eye, so it is impossible to say exactly who and when first discovered them.

You can read more about the planets of the solar system on our website: http://website/index.php/3-planeti-solnechnoy-sistemi.
The closest planet to the Sun is little Mercury. Its orbit is close to the Sun (on an astronomical scale) - the average distance between Mercury and the Sun is "only" 57,900,000 km.

It is difficult to establish a date for the discovery of this planet, but the earliest known observation of Mercury was recorded in the collection Babylonian astronomical tables by Assyrian astronomers around the 14th century BC. uh. The Sumerian name can be read as "jumping planet". Initially, the planet was associated with the god Ninurta (the god of a happy war), and in later records it is called "Naboo" in honor of the god of wisdom and scribal art.
AT Ancient Greece at the time Hesiod the planet was known under the names Στίλβων ("Stilbon") and Ἑρμάων ("Hermaon") - a form of the name of the god Hermes. Later, the Greeks began to call the planet "Apollo".
There is an assumption that the name "Apollo" corresponded to visibility in the morning sky, and "Hermes" ("Hermaon") in the evening. The Romans named the planet after the god of commerce Mercury, who is equivalent to the Greek god Hermes, because he moves through the sky faster than the other planets. Claudius Ptolemy in his work "Hypotheses about the planets" wrote about the possibility of moving the planet through the disk of the Sun. But such a transit has never been observed because a planet like Mercury is too small to observe, or because the moment of transit occurs infrequently.
Observed Mercury and in Ancient China , there he was called Chen-xing (辰星), "Morning Star". The synodic period of Mercury was recognized by Chinese scientists as 115.91 days. In modern Chinese, Korean, Japanese and Vietnamese cultures, the planet began to be called "Water Star" (水星).
In Indian mythology Mercury was called Budha. This god, the son of Soma, was presiding on Wednesdays. In Germanic paganism the god Odin was also associated with the planet Mercury and with the environment. Mayan Indians they represented Mercury as an owl (or, perhaps, as four owls: two corresponded to the morning appearance of Mercury, and two to the evening), which was the messenger of the afterlife. In Hebrew, Mercury was called "Kochav Hama" ("solar planet").
Medieval observations of Mercury in the northern parts of Europe were hampered by the fact that the planet is always observed at dawn - morning or evening - against the background of the twilight sky and rather low above the horizon (especially in northern latitudes). The period of its best visibility occurs several times a year (lasting about 10 days). Even during these periods to see Mercury naked eye not easy (a relatively dim star against a fairly light sky background).
There is a legend that Nicolaus Copernicus regretted that he never saw Mercury in his entire life. Indeed, in the work of Copernicus "On rotations celestial spheres” does not give a single example of observations of Mercury. But he described the planet using the observations of other astronomers. As he himself said, Mercury can still be "caught" from the northern latitudes, showing patience and cunning.
Mercury was first seen through a telescope Galileo Galilei at the beginning of the 17th century, but his telescope was not powerful enough to observe the phases of Mercury. In 1631 Pierre Gassendi made the first telescopic observation of the passage of a planet across the disk of the Sun, but the moment of passage was calculated before that Johannes Kepler. In 1639 Giovanni Zupi using a telescope, he discovered that the orbital phases of Mercury are similar to the phases of the Moon and Venus - this finally confirmed that Mercury revolves around the Sun.
A very rare astronomical event is the overlapping of one planet's disk by another, observed from Earth. Venus overlaps Mercury every few centuries, and this event was observed only once in history - May 28, 1737 John Bevis at the Royal Greenwich Observatory. The next Venus occultation of Mercury will be December 3, 2133.
The difficulties accompanying the observation of Mercury led to the fact that for a long time it was studied less than the other planets.
The proximity of the Sun creates some problems for the telescopic study of Mercury. So, for example, the Hubble telescope has never been used and will not be used to observe this planet. Its device does not allow observations of objects close to the Sun - if you try to do this, the equipment will receive irreversible damage.
Mercury is the least explored planet terrestrial group. Telescopic methods of its study in the 20th century were supplemented by radio astronomy, radar and research using spacecraft.
The latest research data on Mercury:
Mercury's surface temperature: 600 K at the subsolar point and 150 K on the unlit side.
The reflective properties of Mercury and the Moon are similar.
Mercury rotation period: 59 days.
In the picture you see Mariner 10, the first spacecraft to reach Mercury.
Two spacecraft were sent to study Mercury: Mariner 10 flew past Mercury three times in 1974-1975; the maximum approach was 320 km. Several thousand pictures were taken. Further studies from Earth showed the possibility of the existence of water ice in polar craters.
Of all the planets visible to the naked eye, only Mercury has never had its own artificial satellite. NASA is currently on a second mission to Mercury called Messenger. The device was launched on August 3, 2004, and in January 2008 it flew around Mercury for the first time. To enter orbit around the planet in 2011, the device made two more gravitational maneuvers near Mercury.
The European Space Agency (ESA), together with the Japanese Aerospace Exploration Agency (JAXA), is developing the Bepi Colombo mission to explore the surface of Mercury and its depth, as well as to observe the planet's magnetic field and magnetosphere. The launch of the device is planned for 2013.
More opportunities have appeared for ground-based observations of Mercury using CCD radiation receivers and subsequent computer processing of images. On March 17, 2011, the Messenger interplanetary probe entered the orbit of Mercury. According to the first studies, the planet's magnetic field is not symmetrical about the poles; thus northern and south pole Mercury reaches a different number of solar wind particles. We also analyzed the prevalence chemical elements on the planet. Research is ongoing.
Russia plans to send the first landing station "Mercury-P" to the planet. The project was planned for 2019, but was significantly pushed back.

Venus was also observed already in ancient times - it is easy to see it in the sky, because. in brilliance, it far exceeds the brightest stars. For millennia, it has been capturing the eyes of a person to itself. The planet is named after the goddess of love. She has an even White color. Like Mercury, Venus has periods of morning and evening visibility, so in ancient times it was believed that morning and evening Venus were different stars. Through a telescope, one can easily observe the change in the apparent phase of the planet's disk. He was first observed in 1610 Galileo.
On Earth, one can observe the passage of Venus across the disk of the Sun, when this planet is visible from the Earth through a telescope in the form of a small black disk against the background of the huge Sun. For the first time, the passage of Venus across the disk of the Sun was observed on December 4, 1639 by an English astronomer. Jeremiah Horrocks, but first he calculated this phenomenon.
"The phenomenon of Venus on the Sun" observed and M. V. Lomonosov June 6, 1761. This phenomenon was observed all over the world, but only M.V. Lomonosov drew attention to the fact that when Venus came into contact with the disk of the Sun, a “shine as thin as a hair” appeared around the planet. The same bright halo was observed during the descent of Venus from the solar disk. Thus, the presence of an atmosphere on Venus was discovered, and this was a hundred years before the discovery of spectral analysis!
Venus has been intensively studied with the help of spacecraft. First spacecraft, intended for the study of Venus, was the Soviet Venera-1 (February 12, 1961), Soviet devices of the Venera and Vega series, American Mariner, Pioneer-Venera-1, Pioneer- Venera-2", "Magellan", the European "Venus Express", the Japanese "Akatsuki". In 1975, the spacecraft Venera-9 and Venera-10 transmitted the first photographs of the surface of Venus to Earth. But the conditions on the surface of Venus are such that none of the spacecraft has worked on the planet for more than two hours. Roskosmos plans to send the Venera-D station with a satellite of the planet and a more tenacious probe, which should work on the surface of the planet for at least a month.

The exploration of Mars also began a very long time ago - more than 3.5 thousand years ago in Ancient Egypt. The planet was named after Mars, the ancient Roman god of war (corresponding to the ancient Greek Ares). Mars is sometimes referred to as the "red planet" because of the reddish hue of the surface given to it by iron oxide. Mars has moons Phobos and Deimos.
Descriptions of the position of Mars have been preserved, compiled Babylonian astronomers who have developed a number of mathematical methods to predict the position of the planet. Using the data of the Egyptians and Babylonians, ancient Greek philosophers and astronomers developed a detailed geocentric model to explain the motion of the planets. Several centuries later Indian and Islamic astronomers calculated the size of Mars and its distance from Earth. Johannes Kepler introduced a more accurate elliptical orbit of Mars, coinciding with the observed one.
In 1659 Francesco Fontana, considering Mars through a telescope, made the first drawing of the planet - in the form of a black spot.
In 1660, two polar caps were added to the black spot, added Jean Dominique Cassini.
In 1888 Giovanni Schiaparelli gave the first names to individual details of the surface: the seas of Aphrodite, Eritrean, Adriatic, Cimmerian; lakes of the Sun, Lunar and Phoenix.
The heyday of telescopic observations of Mars fell on late XIX- mid-twentieth century.
Since the 1960s, the AMS of the USSR (programs "Mars" and "Phobos"), ESA and the USA (programs "Mariner", "Viking", "Mars Global Surveyor" and others) have been engaged in the study of Mars.
Mars is currently being actively explored. There are three active AMSs in Mars orbit:
"Martian reconnaissance satellite"
Mars Express with Marsis radar
"Mars Odysseus"
Mars rovers operate on the surface of the planet:
Opportunity (since January 25, 2004) as part of the Mars Exploration Rover program
Curiosity (since August 6, 2012) as part of the Mars Science Laboratory program.
Although Mars has been studied much better than other planets, it is still a mystery to us.

Jupiter

Along with Saturn, Uranus and Neptune, Jupiter is a gas giant. This planet has been known to people since ancient times, which is reflected in the mythology and religious beliefs of various cultures: Mesopotamian, Babylonian, Greek and others. Modern name Jupiter comes from the name of the ancient Roman supreme god of thunder. Jupiter has natural satellites. To date, scientists know 67 moons of Jupiter.
At the beginning of the 17th century Galileo Galilei studied Jupiter with the help of the telescope he invented and discovered the four largest satellites of the planet. In the 1660s Giovanni Cassini observed spots and stripes on the "surface" of the giant. In 1671, observing the eclipses of the moons of Jupiter, Danish astronomer Ole Römer found that the true position of the satellites did not match the calculated parameters, and the magnitude of the deviation depended on the distance to the Earth. Based on these observations, Römer concluded that the speed of light was finite and set its value to 215,000 km/s ( contemporary meaning- 299,792.458 km/s).
Since the second half of the 20th century, Jupiter has been actively studied both with the help of ground-based telescopes (including radio telescopes) and with the help of spacecraft - the Hubble telescope and a number of probes. Since the 1970s, 8 NASA interplanetary vehicles have been sent to the planet: Pioneers, Voyagers, Galileo and others.
Jupiter has been studied exclusively by US NASA spacecraft.
Jupiter appears to the naked eye as a bright star. Due to its huge size, even small telescopes can see lightly colored cloud bands and a large red spot on its disk.

Gas giant. Named after the Roman god of agriculture. Saturn has a prominent ring system, consisting mainly of ice particles, a smaller amount of heavy elements and dust. Seeing Saturn for the first time through a telescope in 1609-1610, Galileo Galilei noticed that Saturn does not look like a single celestial body, but like three bodies almost touching each other, and suggested that these are two large "companions" (satellites) of Saturn. In 1633 Gassendi drew a bright ring around Saturn. In 1656 Huygens confirms that there is a thin flat ring around Saturn that does not touch the planet. In 1675 Cassini discovers a gap in the rings, which is later called the Cassini gap, and Encke in 1837 d. finds a second gap. AT 1852 Lassell establishes that the ring of Saturn is almost transparent, which means that it cannot be solid. In addition, he suggested that this ring consists of individual particles located very close to each other, so they seem to be a continuous ribbon. In 1895 Keeler finds that separate parts of the rings rotate at different speeds, and this also confirms Lassell's assumption that the rings cannot be solid.
Saturn has 62 known natural satellites with a confirmed orbit, 53 of which have their own names. Most of the satellites are small and consist of rocks and ice.
Huygens also discovered the largest satellite of Saturn - Titan. There were no further significant discoveries until 1789, when W. Herschel discovered two more satellites - Mimas and Enceladus. Then a group of British astronomers discovered the Hyperion satellite, with a shape very different from spherical. In 1899, William Pickering discovered Phoebe, which belongs to the class of irregular satellites and does not rotate synchronously with Saturn like most satellites. The period of its revolution around the planet is more than 500 days, while the circulation goes in the opposite direction. In 1944 by Gerard Kuiper It was discovered the presence of a powerful atmosphere on another satellite - Titan. This phenomenon is unique for a satellite in the solar system. In the 1990s, Saturn, its moons and rings were repeatedly studied by the Hubble Space Telescope.
Saturn is being explored by automatic interplanetary stations (AMS) "Cassini-Huygens", "Voyager" (program), "Pioneer-11". In 2009, a joint American-European project between NASA and ESA appeared to launch the AMS Titan Saturn System Mission to study Saturn and its moons Titan and Enceladus. During it, the station will fly to the Saturn system for 7-8 years, and then become a satellite of Titan for two years. It will also launch a probe balloon into the atmosphere of Titan and a lander (possibly floating).
The planet is visible from Earth to the naked eye.

uranium was discovered March 13, 1781 by English astronomer William Herschel. While studying the starry sky with his telescope, he noticed that Uranus was moving relative to the stars. Other people have seen Uranus before, even marked it on star charts, but they didn't realize it wasn't a star.
Outside the orbit of Saturn are two planets that have much in common with each other - Uranus and Neptune. Uranus has 27 known natural satellites.
The planet is named after the Greek god of the sky. Uranus is 19 times farther from the Sun than Earth. The journey of Uranus in orbit lasts more than 84 years. When the brilliance of Uranus reaches its maximum, it can be seen with the naked eye, like a star. Uranus is distinguished from other planets by the fact that it makes its way in orbit around the Sun on its side. Maybe he encountered some celestial body and overturned? Uranus also has rings they were discovered in 1977. However, they are barely visible.
NASA's Voyager 2 spacecraft and the Hubble space telescope are exploring Uranus.

Neptune is the eighth and most distant planet in the solar system. The planet was named after the Roman god of the seas.
Based on small deviations in the orbit of Uranus, John Adams and Urbain Le Verrier predicted the existence of another, more distant planet. September 23, 1846 at the request of Le Verrier Johann Galle found new planet- Neptune.
Many people have seen Neptune before, including Galileo Galilei, who, while observing Jupiter, spotted a "star" now believed to be Neptune. Neptune became the first planet discovered through mathematical calculations, and not through regular observations.
Neptune has natural satellites, as well as a fragmented ring system, discovered back in the 1960s, but not reliably confirmed by Voyager 2 until 1989. Triton - amazing companion Neptune, it moves in an orbit in the opposite direction to Neptune.
Voyager 2 explores Neptune. Voyager 2 made its closest approach to Neptune on August 25, 1989. It turned out that Neptune is one of the most beautiful planets in the solar system.

The most distant planet in our solar system is Pluto. She was discovered February 18, 1930 by American astronomer Clyde Tombaugh. He photographed the same part of the night sky in different days, resulting in an object moving relative to the stars. Further observations showed that this object is a planet.
However, there are serious disagreements about this. Pluto doesn't behave like a planet. Pluto's elongated orbit is more like a comet. Due to the fact that Pluto is very far away, it is difficult to see it. Even in the most powerful telescopes, it is visible as a tiny circle. But observations made with advanced technology suggest that Pluto is similar to Neptune's moon, Triton. At first Pluto was classified as a planet, but now it is considered one of the largest objects (perhaps the largest) in the Kuiper belt.

History and structure

The solar system is our planetary system, which includes the Sun and all natural objects revolving around it. It appeared 4.57 billion years ago, when the temperature and pressure created by gravity inside the primary gas and dust cloud led to the onset of a thermonuclear reaction.

The bulk of the mass of the solar system is contained in the sun, while the rest is contained in the planets, dwarf planets, asteroids, comets, dust and gas. Eight relatively solitary planets have relatively circular orbits and are located within the boundaries of an almost flat disk - the plane of the ecliptic. The Earth is part of the so-called terrestrial group, which includes the first four planets from the Sun - Mercury, Venus, and Earth, consisting mainly of silicates and metals. They are followed by a group of four planets more distant from the Sun - Uranus and Neptune (also called gas giants), compared to terrestrial-type planets, their sizes are huge. Especially large are Jupiter and Saturn, the largest in the solar system, consisting mainly of helium and hydrogen; in the composition of Uranus and Neptune, in addition to hydrogen and helium, carbon monoxide and methane are also determined. These planets are also called "ice giants". All gas giants are surrounded by rings of dust and other particles.

Our system has two regions with small bodies. Asteroid belt between Mars and Jupiter includes many objects consisting of silicates and metals, which indicates similarities with terrestrial planets. The largest objects in it are the dwarf planet and the asteroids Vesta, Hygiea and Pallas. Beyond the orbit of Neptune is the so-called Kuiper belt, its objects are composed of water ice, ammonia and methane. Largest Kuiper Belt Objects discovered on this day are considered to be Sedna, Haumea, Makemake, Quaoar, Orc and Eridu.

There are other populations of small bodies in the solar system, such as planetary quasi-satellites and Trojans, near-Earth asteroids, centaurs, damocloids, as well as comets, meteoroids and cosmic dust moving through the system.

The solar wind (a stream of plasma from the Sun) creates a bubble in the interstellar medium called heliosphere, which extends to the edge of the scattered disk. The hypothetical Oort cloud, which is the source of long-period comets, could extend to about a thousand times beyond the heliosphere.

The solar system is part of the Milky Way galaxy.

The central object of the system, the Sun, is a so-called yellow dwarf and belongs to the main sequence stars of the spectral type G2V. Despite this name, the Sun is not a small star at all. Its mass is approximately 99.866% of the mass of the entire system. Approximately 99% of the remaining mass falls on the gas giants (most of this went to Jupiter and Saturn - about 90%).

The movement of most large objects of the solar system occurs in almost one plane, called plane of the ecliptic, but the movement of comets and many Kuiper belt objects often characterizes a large angle of inclination to this plane.

The direction of rotation of all planets and most other objects repeats direction of rotation of the sun, there are exceptions to this rule, for example, Halley's comet.

The largest angular velocity recorded at Mercury - on full turn around the Sun, he spends 88 Earth days, and the most distant planet, Neptune, one revolution around the Sun occurs in 165 Earth years.

For most planets, the direction of rotation around its axis and the direction of rotation around the Sun are the same, the exceptions to this rule are Venus and Uranus. Venus rotates in the opposite direction, and very slowly, one revolution occurs in 243 Earth days, and the axis of rotation of Uranus is inclined to the axis of the ecliptic by almost 90 °, practically it “lies on its side”.

Many planets in the solar system have moons, some of which are larger than Mercury. Often large satellites rotate synchronously, which means that the satellite is always turned to the planet on one side.

The science

Spacecraft that study the planets today:

Planet Mercury

Of the terrestrial planets, perhaps the least of all researchers paid attention to Mercury. Unlike Mars and Venus, Mercury in this group is the least reminiscent of Earth.. It is the smallest planet in the solar system and the closest to the sun.

Photos of the planet's surface taken by the Messenger unmanned spacecraft in 2011 and 2012

So far, only 2 spacecraft have been sent to Mercury - "Mariner-10"(NASA) and "Messanger"(NASA). The first apparatus in 1974-75 circumnavigated the planet three times and came as close as possible to Mercury at a distance 320 kilometers.

Thanks to this mission, thousands of useful photographs were obtained, conclusions were drawn regarding night and day temperatures, relief, and the atmosphere of Mercury. Its magnetic field was also measured.

Spacecraft "Mariner-10" before launch

Information received from the ship "Mariner-10", was not enough, so in 2004 Americans launched a second apparatus to study Mercury - "Messanger", which made it to the orbit of the planet March 18, 2011.

Work on the Messenger spacecraft at the Kennedy Space Center, Florida, USA

Despite the fact that Mercury is a relatively close planet from the Earth, in order to enter its orbit, the spacecraft "Messanger" it took over 6 years. This is due to the fact that it is impossible to get directly from Earth to Mercury due to high speed Earth, so scientists should develop complex gravity maneuvers.

Spacecraft "Messanger" in flight (computer image)

"Messanger" is still orbiting Mercury and continues to make discoveries, though the mission was scheduled for a shorter period. The task of scientists, when working with the apparatus, is to find out what is the geological history of Mercury, what kind of magnetic field the planet has, what is the structure of its core, what unusual materials are at the poles, and so on.

At the end of November 2012 using the apparatus "Messanger" researchers were able to make an incredible and rather unexpected discovery: At the poles of Mercury there is water in the form of ice.

The craters of one of the poles of Mercury, where water was discovered

The strangeness of this phenomenon lies in the fact that, since the planet is located very close to the Sun, the temperature on its surface can rise up to 400 degrees Celsius! However, due to the tilt of the axis, the planet's poles are located in the shadow, where low temperatures persist, so the ice does not melt.

Future flights to Mercury

A new Mercury exploration mission is currently under development called "Bepi Colombo", which is a collaboration between the European Space Agency (ESA) and JAXA from Japan. This ship is scheduled to launch in 2015, although he can finally reach the goal only after 6 years.

The BepiColombo project will include two spacecraft, each with its own tasks

The Russians also plan to launch their ship to Mercury "Mercury-P" in 2019. However, launch date likely to be pushed back. This interplanetary station with a lander will be the first ship to land on the surface of the nearby planets from the sun.

Planet Venus

The inner planet Venus, a neighbor of the Earth, has been extensively explored by space missions, starting since 1961. Since this year, Soviet spacecraft began to be sent to the planet - "Venus" and "Vega".

Comparison of the planets Venus and Earth

Flights to Venus

At the same time, the Americans explored the planet using spacecraft Marier, Pioneer-Venus-1, Pioneer-Venus-2, Magellan. The European Space Agency is currently working with the spacecraft "Venus Express", which operates since 2006. In 2010 year The Japanese ship went to Venus "Akatsuki".

Apparatus "Venus Express" reached the destination in April 2006. It was planned that this ship would complete the mission in 500 days or 2 Venusian years, but over time the mission was extended.

Spacecraft "Venera-Express" in operation according to the artist's ideas

The aim of this project was to study in more detail the complex chemical composition planets, characteristics of the planet, the interaction between the atmosphere and the surface, and much more. Scientists also want to know more about the history of the planet and understand why a planet so similar to the Earth went a completely different evolutionary path.

"Venus-Express" during construction

Japanese spacecraft "Akatsuki", also known as PLANET-C, was launched in May 2010, but after approaching Venus in December, could not reach its orbit.

What to do with this device is not yet clear, but scientists do not lose hope that it is still can complete his task albeit very late. Most likely, the ship did not enter orbit due to problems with a valve in the fuel line, which caused the engine to stop prematurely.

New spaceships

November 2013 planned to launch "European explorer of Venus"- the probe of the European Space Agency, which is being prepared to study the atmosphere of our neighbor. The project will include two satellites, which, turning around the planet in different orbits, will collect the necessary information.

The surface of Venus is hot, and Earth ships should have good protection.

Also in 2016 Russia plans to send a spacecraft to Venus "Venus-D" to study the atmosphere and surface in order to find out Where did the water from this planet go?

The descent vehicle and balloon probe will have to work on the surface of Venus about a week.

The planet Mars

Today, Mars is studied and explored most intensively, and not only because this planet is so close to Earth, but also because conditions on Mars are closest to those on Earth, therefore, extraterrestrial life is primarily looked for there.

Currently working on Mars three orbiting satellites and 2 rovers, and before them, Mars was visited by a huge number of terrestrial spacecraft, some of which, unfortunately, failed.

In October 2001 NASA orbiter "Mars Odysseus" went into orbit around the Red Planet. He allowed to put forward the assumption that under the surface of Mars there may be deposits of water in the form of ice. It's confirmed in 2008 after years of exploring the planet.

Mars Odysseus probe (computer image)

Apparatus "Mars Odysseus" successfully operates today, which is a record for the duration of the operation of such devices.

In 2004 in different parts of the planet Gusev crater and on meridian plateau rovers landed accordingly "Spirit" and "Opportunity", which were supposed to find evidence of the existence of liquid water on Mars in the past.

rover "Spirit" stuck in the sand after 5 years of successful work, and eventually communication with him was interrupted from March 2010. Because of the harsh winter on Mars, the temperature was not enough to keep the batteries running. Project's second rover "Opportunity" also turned out to be quite tenacious and is still working on the Red Planet.

Panorama of Erebus crater taken by the Opportunity rover in 2005

From August 6, 2012 NASA's newest rover is working on the surface of Mars "Curiosity", which is several times larger and heavier than previous rovers. Its task is to analyze the Martian soil and atmospheric components. But the main task of the device is to establish, Is there life on Mars, or perhaps she's been here in the past. It is also a task to obtain detailed information about the geology of Mars and its climate.

Comparison of rovers from smallest to largest: Sojourner, Oppotunity and Curiosity

Also with the help of the rover "Curiosity" researchers want to prepare for human flight to the red planet. During the mission, traces of oxygen and chlorine were found in the Martian atmosphere, and traces of a dried-up river were also found.

The Curiosity rover in action. February 2013

A couple of weeks ago, the rover managed to drill small hole in the ground Mars, which turned out to be not red at all, but gray. Soil samples from a shallow depth were taken by the rover for analysis.

Using a drill, a hole 6.5 centimeters deep was made in the ground and samples were taken for analysis.

Missions to Mars in the future

In the near future, researchers from various space agencies are planning more multiple missions to Mars, the purpose of which is to obtain more detailed information about the Red Planet. Among them is an interplanetary probe "MAVEN"(NASA), which will go to the Red Planet in November 2013.

European mobile laboratory planned to go to Mars in 2018, which will continue to work "Curiosity", will be engaged in soil drilling and sample analysis.

Russian automatic interplanetary station "Phobos-Grunt 2" planned for launch in 2018 and is also going to take soil samples from Mars to bring back to Earth.

Work on the device "Phobos-Grunt 2" after an unsuccessful attempt to launch "Phobos-Grunt-1"

As you know, beyond the orbit of Mars is asteroid belt, which separates the terrestrial planets from the rest of the outer planets. Very few spacecraft have been sent to the far corners of our solar system, which is due to huge energy costs and other complexities of flying over such vast distances.

Basically, Americans prepared space missions for distant planets. In the 70s of the last century the parade of planets was observed, which happens very rarely, so it was impossible to miss such an opportunity to fly around all the planets at once.

Planet Jupiter

So far, only NASA spacecraft have been launched to Jupiter. Late 1980s - early 1990s The USSR planned their missions, however, due to the collapse of the Union, they were never implemented.

The first vehicles that flew up to Jupiter were "Pioneer-10" and "Pioneer-11", which approached the giant planet in 1973-74 years. In 1979 high-resolution images were taken by devices Voyagers.

The last spacecraft orbiting Jupiter was "Galileo" whose mission began in 1989, but ended in 2003. This device was the first to enter the orbit of the planet, and not just fly by. He helped to study the atmosphere of the gas giant from the inside, its satellites, and also helped to observe the fall of fragments comet Shoemakerov-Levy 9 that crashed into Jupiter in July 1994.

Galileo spacecraft (computer image)

With the help of the device "Galileo" managed to fix severe thunderstorms and lightning in the atmosphere of Jupiter, which are a thousand times stronger than the earth! The device also captured Jupiter's Great Red Spot, which astronomers have replaced yet 300 years ago. The diameter of this giant storm is larger than the diameter of the Earth.

Discoveries were also made related to the satellites of Jupiter - very interesting objects. For example, "Galileo" helped to establish that under the surface of Europa's satellite there is ocean of liquid water, and the satellite Io has its magnetic field.

Jupiter and its moons

After completing the mission "Galileo" melted in Jupiter's upper atmosphere.

Flight to Jupiter

In 2011 NASA launched a new device to Jupiter - a space station "Juno", which must reach the planet and go into orbit in 2016. Its purpose is to help research magnetic field planets as well "Juno" should find out if Jupiter has hard core Or is it just a hypothesis.

Spacecraft "Juno" will reach the goal only after 3 years

Last year, the European Space Agency announced its intention to prepare for 2022 new European-Russian mission to study Jupiter and its satellites Ganymede, Callisto and Europa. The plans also include landing the device on the Ganymede satellite. in 2030.

Planet Saturn

For the first time, an apparatus flew up to the planet Saturn at a close distance "Pioneer-11" and this happened in 1979. A year later the planet visited Voyager 1, and a year later Voyager 2. These three devices flew past Saturn, but managed to make a lot of useful images for researchers.

Detailed images of Saturn's famous rings were taken, the planet's magnetic field was discovered, and powerful storms were seen in the atmosphere.

Saturn and its moon Titan

It took 7 years for an automatic space station "Cassini-Huygens", to in July 2007 enter the orbit of the planet. This apparatus, consisting of two elements, was supposed, in addition to Saturn itself, to study its Titan's largest moon, which was successfully completed.

Cassini-Huygens spacecraft (computer image)

Saturn's moon Titan

The existence of liquid and atmosphere on the Titan satellite has been proven. Scientists have suggested that the satellite is quite the simplest forms of life can exist, however, this still needs to be proven.

Photo of Saturn's moon Titan

At first it was planned that the mission "Cassini" will be until 2008, but later it was extended several times. In the near future, new joint missions of Americans and Europeans to Saturn and its satellites are planned. Titan and Enceladus.

Planets Uranus and Neptune

These distant planets, which are not visible to the naked eye, are mostly studied by astronomers from Earth. with telescopes. The only apparatus that approached them was Voyager 2, which, having visited Saturn, went to Uranus and Neptune.

First Voyager 2 flew past Uranus in 1986 and took pictures up close. Uranus turned out to be completely inexpressive: storms or cloud bands that other giant planets have were not noticed on it.

Voyager 2 flying past Uranus (computer image)

With the help of a spacecraft Voyager 2 found a lot of details, including rings of Uranus, new satellites. Everything we know about this planet today is thanks to Voyager 2, which swept past Uranus at great speed and took several pictures.

Voyager 2 flying past Neptune (computer image)

In 1989 Voyager 2 got to Neptune, taking pictures of the planet and its satellite. Then it was confirmed that the planet has magnetic field and the Great Dark Spot, which is a persistent storm. Neptune has also been found to have faint rings and new moons.

New devices to Uranus are planned to be launched in the 2020s, but exact dates have not yet been announced. NASA intends to send not only an orbiter to Uranus, but also an atmospheric probe.

Spacecraft "Urane Orbiter" heading for Uranus (computer image)

Planet Pluto

In the past the planet, and today dwarf planet Pluto- one of the most distant objects in the solar system, which makes it difficult to study. Flying past other distant planets, neither Voyager 1, neither Voyager 2 it was not possible to visit Pluto, so all our knowledge about this object we got thanks to telescopes.

New Horizons spacecraft (computer render)

Until the end of the 20th century astronomers were not particularly interested in Pluto, and they threw all their efforts into the study of closer planets. Due to the remoteness of the planet, large costs were required, especially so that a potential device could be powered by energy while away from the Sun.

Finally, only at the beginning of 2006 NASA spacecraft successfully launched "New Horizons". He is still on the way: it is planned that in August 2014 it will be next to Neptune, and only in July 2015.

Rocket launch with the New Horizons spacecraft from Cape Canaveral, Florida, USA, 2006

Unfortunately, modern technologies will not allow the device to enter Pluto's orbit and slow down for now, so it just will pass by a dwarf planet. Within six months, researchers will have the opportunity to study the data they will receive using the device. "New Horizons".