The smallest planet from the sun. The most famous comet closest star cluster

Since ancient times, people have looked at the sky and stars, they made predictions, determined the location, etc. Scientists are working on the study of planets and stars. Which of the planets is the smallest?

Planets smaller than Earth

Venus is almost the same as Earth in both size and mass. From the earth's mass, its mass is 0.815. It is known that the orbit around the Sun is completed by it in almost two hundred and twenty-five Earth days. There is water, but it is much less than on Earth. After the Moon with the Sun in the sky of our planet, it is Venus that is the third brightest luminary. The following is known about it - the surface temperature is more than four hundred degrees, the extremely high density of the atmosphere, the absence of satellites. Despite the apparent similarity of the planet with the Earth, they have too many important differences. The surface of Venus cannot be seen due to the fact that it is covered with dense clouds consisting of sulfuric acid. These clouds are highly reflective. The relief was explored only thanks to radio waves.

Planetology as a science suggests that most likely at one time there were oceans on the planet, similar to those that are now on Earth. This planet has been little studied, despite the fact that its surface has been explored by more than one spacecraft. It should be noted that none of them worked more than two hours due to difficult conditions. It was thanks to these spacecraft that the photographs of the surface of this planet made by them first appeared on Earth. This happened in 1975.

Another planet that is much smaller when compared to Earth is Mars. It received its second name "red planet" due to the presence of iron oxide on the surface. She was given a name in honor of the ancient Roman god of war. She has two natural satellites named Deimos and Phobos. Scientists from many countries are studying the "red planet". According to them, there may be water on it, but it is not in a liquid state, which is due to too low pressure on the surface. Such a conclusion indicates that primitive life on the planet may well exist.

Thanks to research and the work of rovers, scientists have found out that once the surface was covered with water. The climate on the planet is seasonal, the average temperature is minus fifty degrees. A person can easily see Mars even with the naked eye. It is known that its mass is less than eleven percent of the earth's mass.

The smallest planets in the solar system

Officially, today the most miniature planet of our solar system considered to be a planet called Mercury. It moves much faster than other planets, most likely because of this it was given just such a name. After all, as you know, the god of trade Mercury was fleet. Its mass is 3.3 1023 kg. Relative to the mass of the Earth, the mass of Mercury is 0.055. Given the density, it can be argued that its bowels contain a lot of metals. This small planet revolves around the sun in eighty-eight Earth days.

Mercury is very little studied, but it is known that it has no satellites. Its well-known features include numerous jagged escarpments and impact craters.

The smallest planet in the galaxy

It remains to be content only with what is already known for certain about our solar system, namely, that the smallest planet until 2006 was Pluto, and now Mercury has taken its place.

Meanwhile, the largest planet is in the constellation Hercules.

What is it called: Mercury | Area: 74,797,000 km2

Equatorial circumference: 15,329.1 km

The most nearby planet to the Sun since 2006, it has also received the title of the smallest planet in the solar system. This was due to the fact that Pluto was excluded from the category of full-fledged planets and attributed to dwarf planets.

The diameter of Mercury is only 4,900 km, for comparison with the Earth, this figure is 12,742 km. And if we compare the volumes of the planets, then Mercury has only 0.05 of the size of the Earth.

Research

Astronomers began to observe this planet a very long time ago. The first written references date back to the 14th century. BC. in the document "Mul' apin" compiled by Assyrian astronomers.

In 1631, scientists first observed the planet through a telescope and saw the passage of Mercury across the solar disk.

At the end of the 20th century, the Mariner 10 satellite was engaged in the study of Mercury, which for the first time transmitted images of its surface. In 2008-2011 the planet was surveyed by spaceship Messenger, with which scientists took pictures of almost the entire surface of the smallest planet, and conducted a series of geomagnetic and geological studies.

Appearance of the planet Mercury

The surface of Mercury has a brownish-gray color. In terms of relief, it is very similar to the Moon, since the entire outer layer is simply strewn with many craters from collisions with cosmic bodies. Scientists explain this mass defeat planets by what she has almost no atmosphere, which could protect against meteorites and comets.

In addition, the planet has very long mountain ranges in the form of sharp ledges and rocks, giant surface "folds".

The smallest planet in our solar system is Mercury.

Eruptions on a grand scale

The study of the surface of the planet confirmed that during the formation of the planet, many volcanoes were active throughout the surface. The evidence of such phenomena is best preserved at the north pole, since it was the least attacked by cosmic bodies.

Based on the data obtained, scientists claim that the lava layer at the north pole reaches 2 km. Lava flowed from volcanic holes formed as a result of damage to the outer shell. The largest lava tunnel discovered by the satellite is 25 km. According to estimates, a volume of lava that could cover 200 km 2 should have flowed through such a hole.

Atmosphere

Scientists for a long time were convinced that the atmosphere on Mercury is completely absent. But in the course of research by Mariner 10, it was found that there are still gases on the surface of the planet, albeit in very small quantities.

The atmosphere of Mercury is more correctly called the exosphere. It consists of oxygen (O2), hydrogen (H2), sodium (Na), potassium (K) and helium (He). Due to weak gravity, gases do not linger at the surface of the planet and fly away into outer space. According to the assumptions of scientists, helium and hydrogen are formed on Mercury, and the rest of the elements enter the exosphere due to solar winds.

Magnetic storms

Instead of atmospheric storms, magnetic storms very often rage on Mercury. Although the planet's magnetic field is very weak (only 1% of the power compared to the earth's), strong magnetic tornadoes occasionally arise from interaction with solar wind particles.

Temperature

Due to the lack of a full-fledged atmosphere, the largest temperature amplitude in the solar system is recorded on the planet. The maximum value is approx. +427°С, and the minimum is close to – 173°С.

Despite its proximity to the Sun and a record high of +427°C, Venus is considered the hottest planet, as its average temperature is much higher.

Ice

Even Mercury has ice. Such assumptions appeared among scientists as early as 1991, and thanks to the data from the Messenger's radars, they were confirmed. The ice is found in deep craters at the north and south poles in a zone of permanent shadow.

North Pole of Mercury. The large crater "Prokofiev" is visible. There is ice in the craters. From above, the ice is covered with some kind of organic dark substance. photo:NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Mercury time

One day on Mercury lasts about 176 Earth days., and a year is 88 days. Such unusual data are logical explanation. It's just that the speed of the planet's orbit is many times higher than the speed of rotation around its own axis. And it turns out that it circles around the Sun faster than around itself.

There are versions that earlier the speed of rotation around its axis was much higher, but over time it decreases under the influence of the Sun.

Density and gravity

Although Mercury is very small, it has a high density, as it consists of stones and iron. In the solar system, it has the second place in terms of density - 5.43 g / cm3. In the first place is the Earth because of its large size and centrifugal force.

The force of gravity on the planet is 38% of that of the earth, so if you weigh 100 kg on Earth, then the scales on Mercury will show 38 kg.

Core

Analyzing data from the Messenger, the researchers found that the iron core of Mercury is in a liquid state, and has a radius of about 2 thousand kilometers. Which is 80% of the total radius of the planet. Such proportions between the core and the rest of the layers are not observed in any known planet.

How is the phenomenon of a large nucleus explained?

There are 2 working versions:

1. Mercury was originally 2.25 times its current size. After a collision with a large cosmic body, he lost most of the outer layers and took on its current appearance.
2. At the time of the formation of the planet, the Sun carried light elements into distant regions interplanetary space, so its structure is saturated with such dense substances.

Mercury is decreasing

According to astronomers, the core of Mercury is gradually cooling and shrinking in size. This is the cause of massive earthquakes and a decrease in the size of the planet. Proof of this are the long steep ledges on its surface.

Unique orbital movement

Mercury also distinguished itself by the nature of its orbital movement - it has a variable speed of movement. At a distance from the Sun, it moves slowly, and in the area next to it, it speeds up several times. This feature of Mercury led to the fact that the Sun stops for a while and begins to move in the opposite direction.

In fairness, it should be noted that the rotation around its axis is a constant value.

Passage on the solar disk

Since Mercury is closest to the Sun, it is extremely difficult to see it from Earth. Except at dawn or dusk. But 13 times in a century, a small planet makes a passage across the solar disk. In the 21st century, he has already done this 2 times - 05/07/2013 and 11/08/2006. The nearest similar event will take place on 05/09/2016 and 11/11/2019.

Mercury is the smallest planet in our solar system. The clearest image of Mercury ever taken by NASA is from the Messenger mission. The colors are deliberately more saturated.

• From Mercury to the Sun about 58 million km.
• To reach the orbit of Mercury, the Messenger traveled 79 million km and was forced to circle the Sun 15 times in order to synchronize with the planet.
• When Mercury is closest to the Sun, it is 3 times larger than what we see from Earth.
• Thanks to less gravity, a person on Mercury would be able to jump 2.6 times higher than on our planet.
• The spacecraft flies from Earth to Mercury in 6 years.
• Mercury's radio signal to Earth and back will return in 5 minutes.
• In terms of size, the small planet loses even to some satellites of the giant planets, for example, Titan and Ganymede.
• The core of Mercury is commensurate with the size of the Moon.
• Near the two poles of the planet are areas that never get the rays of the sun.
• It is assumed that the layer of ice on Mercury reaches 2 m.
• Only on Mercury can one observe how the Sun rises (or sets) twice in one day.
• The largest Mercury crater is 716 km in diameter, the researchers named it Rembrandt.
• The largest ledge called Discovery is 350 km long and 3 km high.
• At the level of 1 m under the outer shell of Mercury, there are no temperature fluctuations. Here it is constantly at around + 75 ° C.
• The planet has a comet-like tail, the length of which exceeds 2.5 million km.
• If the Earth were empty inside, 20 Mercurys would fit in it.

Jupiter and Earth compared

• The most big planet Solar system - Jupiter. This is the fifth planet from the Sun, it is more than 2.5 times heavier than all the other planets combined! Jupiter's equator is about 11 times the diameter of the Earth, its length is 143884 km!

Mercury and Earth compared

• The smallest planet in the solar system is Mercury. Its diameter is only 4789 km. In size, it is inferior even to some satellites, such as Jupiter's Ganymede and Saturn's Titan.
• Paradoxically, the very big planet- Jupiter, the smallest known moon. It is called Leda and its diameter is 10 km.
• Pallas is the largest asteroid. Diameter - 490 km. Until 2006, Ceres was considered the largest asteroid, until it was given the status of a dwarf planet.

• One of the most interesting mysteries of the sun- This is the solar corona (outer part of the atmosphere), the temperature of which is higher than that of the star itself.
• Jupiter beats all the records of the solar system. He has the most a large number of satellites - 63! Its closest competitor is Saturn with 60 moons.
• The brightest planet in the solar system is Venus. More precisely, it is a planet that reflects the largest number sunlight– 76%. This property is due to special clouds in the atmosphere of Venus. It is the third brightest object in the Earth's sky, second only to the Sun and Moon.

• The brightest comet with the prosaic name C / 1910 A1 surpasses even Venus in brightness. It is also known as the Great January Comet, as it was discovered in January 1910.
• The brightest asteroid- Vesta. It is the only asteroid that can be seen with the naked eye in the night sky.
• The coldest place The solar system is the satellite of Neptune, Triton. It is 38 degrees warmer than absolute zero, that is, -235.
• Neptune - windiest planet. Large atmospheric formations at Neptune's equator move at a speed of 320 m/s, and smaller ones move twice as fast.

• Until 08/24/2006, it was believed that there were 9 planets in the solar system. But now there are 8 of them because the International Astronomical Union has excluded dwarf Pluto from the list. But now a new study has been done that shows that Pluto may need to be re-qualified again. So in the near future there may be 9 planets again!

The largest planet in the solar system

Jupiter. Its equatorial diameter is 143884 km, which is 11.209 times the diameter of the Earth and is 0.103 times the diameter of the Sun. Jupiter's shape is not entirely spherical because the planet is made up of gas and liquid and rotates rapidly. Jupiter's polar diameter is 133,708 km. The mass of Jupiter is 318 times the mass of the Earth and 2.5 times the mass of all the other planets combined. Jupiter is only 1047 times less massive than the Sun.

The smallest planet in the solar system

Pluto. Its diameter is only 2400 km. The rotation period is 6.39 days. The mass is 500 times less than the earth. It has a satellite Charon, discovered by J. Christie and R. Harrington in 1978.

The brightest planet in the solar system

Venus. Its maximum magnitude is -4.4. Venus is closest to the Earth and, in addition, reflects sunlight most effectively, since the surface of the planet is covered with clouds. The upper clouds of Venus reflect 76% of the sunlight falling on them. When Venus appears at its brightest, it is in its crescent phase. The orbit of Venus lies closer to the Sun than the orbit of the Earth, so the disk of Venus is only fully illuminated when it is on the opposite side from the Sun. At this time, the distance to Venus is the largest, and its apparent diameter is the smallest.

The largest satellite in the solar system

Ganymede is a moon of Jupiter with a diameter of 5262 km. The largest moon of Saturn, Titan, is the second largest (its diameter is 5150 km), and at one time it was even believed that Titan was larger than Ganymede. In third place is Jupiter's satellite Callisto, adjacent to Ganymede. Both Ganymede and Callisto are larger than the planet Mercury (which has a diameter of 4878 km). Ganymede owes its status as the "largest moon" to a thick mantle of ice that covers its interior rock layers. The solid cores of Ganymede and Callisto are probably close in size to Jupiter's two small Galilean inner moons, Io (3630 km) and Europa (3138 km).

The smallest moon in the solar system

Deimos is a satellite of Mars. The smallest satellite, the dimensions of which are precisely known - Deimos, roughly speaking, has the shape of an ellipsoid with dimensions of 15x12x11 km. Its possible rival is Jupiter's moon Leda, which is estimated to be about 10 km in diameter.

The largest asteroid in the solar system

Ceres. Its dimensions are 970x930 km. In addition, this asteroid was discovered the very first. It was discovered by the Italian astronomer Giuseppe Piazzi on January 1, 1801. The asteroid got its name because Ceres, the Roman goddess, was associated with Sicily, where Piazzi was born. The next largest asteroid after Ceres is Pallas, discovered in 1802. Its diameter is 523 km. Ceres revolves around the Sun in the main asteroid belt, being at a distance of 2.7 AU from it. e. It contains a third total weight all over seven thousand known asteroids. Although Ceres is the largest asteroid, it is not the brightest because its dark surface reflects only 9% of sunlight. Its brightness reaches 7.3 magnitude.

The brightest asteroid in the solar system

Vesta. Its brightness reaches magnitude 5.5. When the sky is very dark, Vesta can even be detected with the naked eye (it is the only asteroid that can be seen at all with the naked eye). The next brightest asteroid is Ceres, but its brightness never exceeds magnitude 7.3. Although Vesta is more than half the size of Ceres, it is much more reflective. Vesta reflects about 25% of the sunlight falling on it, while Ceres only 5%.

The largest crater on the moon

Hertzsprung. Its diameter is 591 km and it is located on reverse side Moon. This crater is a multi-ringed impact piece. Similar percussive structures on visible side The moons were later filled with lava, which solidified into dark, hard rock. These features are now commonly referred to as seas rather than craters. However, such volcanic eruptions did not occur on the far side of the Moon.

most famous comet

Halley's Comet has been traced back to 239 BC. No other comet has historical records that can compare with Halley's comet. Halley's comet is unique: it has been observed for more than two thousand years 30 times. This is because Halley's comet is much larger and more active than other periodic comets. The comet is named after Edmund Halley, who in 1705 understood the connection between several previous comet appearances and predicted its return in 1758-59. In 1986, the Giotto spacecraft was able to image the nucleus of Halley's comet from a distance of just 10,000 kilometers. It turned out that the core has a length of 15 km and a width of 8 km.

The brightest comets

The brightest comets of the 20th century include the so-called "Great Daylight Comet" (1910), Halley's comet (when it appeared in the same 1910), the Shellerup-Maristani comets (1927), Bennett (1970) , Vesta (1976), Hale-Bopp (1997). The brightest comets of the 19th century are probably the "Great Comets" of 1811, 1861, and 1882. Previously, very bright comets were recorded in 1743, 1577, 1471 and 1402. The closest (and brightest) appearance of Halley's comet to us was noted in 837.

closest comet

Leksel. The smallest distance to the Earth was reached on July 1, 1770 and amounted to 0.015 astronomical units (i.e. 2.244 million kilometers or about 3 diameters of the Moon's orbit). When the comet was closest, the apparent size of its coma was almost five diameters. full moon. The comet was discovered by Charles Messier on June 14, 1770, but got its name from Anders Johann (Andrey Ivanovich) Leksel, who determined the orbit of the comet and published the results of his calculations in 1772 and 1779. He found that in 1767 the comet came close to Jupiter and, under its gravitational influence, moved into an orbit that passed near the Earth.

Longest total solar eclipse

Theoretically, the total phase of the eclipse can take all the time of the total solar eclipse- 7 minutes 31 seconds. In practice, however, no such long eclipses have been recorded. The longest total eclipse in the recent past there was an eclipse on June 20, 1955. It was observed from the Philippine Islands, and the total phase lasted 7 minutes 8 seconds. The longest eclipse in the future will take place on July 5, 2168, when the total phase will last 7 minutes 28 seconds.

closest star

Proxima Centauri. It is located at a distance of 4.25 light years from the Sun. It is believed that together with the double star Alpha Centauri A and B, it is part of a free triple system. The double star Alpha Centauri is a little further away from us, at a distance of 4.4 light years. The Sun lies in one of the spiral arms of the Galaxy (the Orion Arm), at a distance of about 28,000 light-years from its center. At the location of the Sun, stars are usually several light-years apart.

The most bright Star

Sirius. Its magnitude is -1.44. Sirius got its name from Ancient Greece, and it means "scorching". Sirius is sometimes called the Dog Star after the constellation. Big Dog to which it belongs. At just 8.7 light-years away, Sirius is one of the closest stars to the Sun. The next brightest star after Sirius is Canopus in the constellation Carina, with a magnitude of -0.72. In fact, Sirius is a system of two stars rotating around each other. Almost all light comes to us from the main star, which is called Sirius A and is a white normal star about 2.3 times as massive as the Sun. A fainter companion, Sirius B, discovered by visual observation in 1862, is a white dwarf. The light from Sirius B is only one ten-thousandth of the light of Sirius A. The Sirius binary system completes one rotation in 50 years.

The most powerful star in terms of radiation

Star in the Pistol. In 1997, astronomers working with the Hubble Space Telescope discovered this star. They named it "The Gun Star" after the shape of the nebula surrounding it. Although the radiation of this star is 10 million times stronger than the radiation of the Sun, it is not visible to the naked eye, because it is located near the center of the Milky Way at a distance of 25,000 light years from Earth and is hidden by large clouds of dust. Prior to the discovery of the Star in the Gun, the most serious contender was Eta Carinae, whose luminosity was 4 million times that of the Sun.

The biggest star

Mu Cephei. Currently, the star mu Cephei is considered the largest, with a diameter of more than 1.6 billion kilometers. Placed in the center of the solar system, this star would swallow up all the planets up to and including Saturn.

The fastest star

Barnard's Star. Opened in 1916 and is still the star with the largest proper motion. The unofficial name of the star (Barnard's Star) is now generally accepted. Its own motion per year is 10.31". Barnard's Star is one of the closest stars to the Sun (next after Proxima Centauri and the Alpha Centauri A and B binary systems). In addition, Barnard's Star also moves in the direction of the Sun, approaching it at 0.036 light years per century.In 9000 years, it will become the closest star, taking the place of Proxima Centauri.

The brightest supernova

A star from the constellation of the Wolf observed in 1006 AD. Based on many surviving records of observations, it can be established that the apparent stellar magnitude of the supernova was about -10, which is comparable to the Moon. The position of this supernova was identified by a known supernova remnant (number PKS 1459-41), which emits in the radio and X-ray ranges and is observed in the optical range as faint filaments. The distance to the supernova is estimated at 3260 light years. At the moment of maximum brightness, all supernovae reach approximately the same absolute magnitudes, but their apparent brightness depends both on the distance and on the amount of dust in the path of the light beam. The next brightest (after the supernova of 1006) is the explosion of 1054, which resulted in the appearance of the Crab Nebula in Taurus. This supernova reached an apparent magnitude of -5.

Largest known globular cluster

Omega Centauri. It contains millions of stars, concentrated in a volume with a diameter of about 620 light years. The shape of the cluster is not quite spherical: it looks slightly flattened. In addition, Omega Centauri is also the brightest globular cluster in the sky with a total magnitude of 3.6. It is 16,500 light years away from us. The name of the cluster has the same form as the names of individual stars usually have. It was assigned to the cluster a long time ago, when it was impossible to recognize the true nature of the object with the naked eye. Omega Centauri is one of the oldest clusters.

closest galaxy

The dwarf galaxy in the constellation Sagittarius is the closest galaxy to the Milky Way Galaxy. This small galaxy is so close that the Milky Way seems to be swallowing it up. The galaxy lies at a distance of 80,000 light years from the Sun and 52,000 light years from the center of the Milky Way. The next closest galaxy to us is the Large Magellanic Cloud, 170,000 light-years away.

The farthest object visible to the naked eye

The farthest object that can be seen with the naked eye is the Andromeda Galaxy (M31). It lies at a distance of about 2 million light years, and is approximately equal in brightness to a star of the 4th magnitude. It is a very large spiral galaxy, the largest member of the Local Group, to which our own galaxy belongs. In addition to it, only two other galaxies can be observed with the naked eye - the Large and Small Magellanic Clouds. They are brighter than the Andromeda Nebula, but much smaller and less distant (at 170,000 and 210,000 light years, respectively). However, it should be noted that vigilant people in dark night can see the M31 galaxy in the constellation Ursa Major, the distance to which is 1.6 Megaparsecs.

largest constellation

Hydra. The area of ​​the sky, which is part of the constellation Hydra, is 1302.84 square degrees, which is 3.16% of the entire sky. The next largest constellation is Virgo, occupying 1294.43 square degrees. Most of the constellation Hydra lies south of the celestial equator, and its total length is over 100°. Despite its size, the Hydra doesn't really stand out in the sky. It mainly consists of rather faint stars and is not easy to find. The brightest star is Alphard, an orange giant of the second magnitude, located at a distance of 130 light-years.

smallest constellation

South Cross. This constellation occupies an area of ​​the sky of only 68.45 square degrees, which is equivalent to 0.166% of the entire sky area. Despite its small size, the Southern Cross is a very prominent constellation that has become a symbol of the southern hemisphere. It contains twenty stars brighter than magnitude 5.5. Three of the four stars that form his cross are stars of the 1st magnitude. In the constellation of the Southern Cross is an open star cluster (Kappa Southern Cross, or "Jewel Box" cluster), which many observers consider one of the most beautiful in the sky. The next smallest constellation in size (more precisely, occupying the 87th place among all the constellations) is the Little Horse. It covers 71.64 square degrees, i.e. 0.174% of the sky area.

The largest optical telescopes

The two Keck Telescopes side by side on top of Mauna Kea, Hawaii. Each of them has a reflector with a diameter of 10 meters, composed of 36 hexagonal elements. They were intended from the outset for joint work. Since 1976, the largest optical telescope with a solid mirror has been the Russian Large Azimuth Telescope. Its mirror has a diameter of 6.0 m. For 28 years (1948 - 1976), the largest optical telescope in the world was the Hale Telescope on Mount Palomar in California. Its mirror is 5 m in diameter. Very Big Telescope, located in Cerro Paranal in Chile, is a structure of four mirrors with a diameter of 8.2 m, which are connected together to form a single telescope with a 16.4-meter reflector.

The world's largest radio telescope

Radio telescope of the Arecib observatory in Puerto Rico. It is built into a natural depression on the earth's surface and has a diameter of 305 m. The world's largest fully steerable radio antenna is the Green Bank Telescope in West Virginia, USA. Its antenna diameter is 100 m. The largest array of radio telescopes located in one place is the Very Large Array (VLA, or VLA), which consists of 27 antennas and is located near Socorro in New Mexico, USA. In Russia, the largest radio telescope "RATAN-600" with a diameter of antenna-mirrors installed around the circumference of 600 meters.

The closest galaxies

The astronomical object numbered M31, better known as the Andromeda Nebula, is located closer to us than all other giant galaxies. In the northern hemisphere of the sky, this galaxy appears to be the brightest from Earth. The distance to it is only 670 kpc, which in our usual measurements is a little less than 2.2 million light years. The mass of this galaxy is 3 x 10 more than the mass of the Sun. Despite its huge size and mass, the Andromeda Nebula is similar to the Milky Way. Both galaxies are giant spiral galaxies. The closest from us are the small satellites of our Galaxy - the Large and Small Magellanic Clouds of irregular configuration. The distance to these objects is 170 thousand and 205 thousand light years, respectively, which is negligible compared to the distances used in astronomical calculations. Magellanic clouds are visible to the naked eye in the sky in the Southern Hemisphere.

The most distant galaxies

Among the astrophysicists who have devoted their creative activity to the study of distant galaxies, H. Spinrad, an employee of the University of California at Berkeley, stands out. He owns the discovery of more than one ultra-distant galaxy. Spinrad originally discovered the record-breaking galaxy north of the Pleiades star cluster in 1975, 8 billion light-years away. This galaxy is listed in the star catalog under the number 3C 123. It has the strongest level of radio emission, exceeding the strength of such radiation from other giant galaxies by about 6 times.

In another series of observations made in 1984 using the 4-meter reflector of the Kitt Peak National Observatory in US state Arizona, Spinrad discovered a number of radio galaxies, among which were the most distant known to science.

Optical radiation, for example, from the radio galaxy 3C 256 reaches the solar system for a long 10 billion years. In addition, the distance continues to increase, as it moves away from us at a speed of 200 thousand km / s. Unlike other nearby radio galaxies with pronounced elliptical shapes, this one has an irregularly elongated configuration. A more or less clear image of another record-holding galaxy in range was recently obtained by the American astronomers K. Chambers and J. Mealy at the Leiden Observatory. The distance to it is 12 billion light years.

It is no coincidence that astrophysicists pay their close attention to ultra-distant astronomical objects. By processing information collected over more than one billion light-years, one can form a generalized idea of ​​the distant past of stellar formations, especially at the initial stages of their formation and origin, during the period corresponding to the beginning of the expansion of the Universe. The discoveries of ever new ultra-distant galaxies are by no means accidental. They are most often the fruit of many years of purposeful work by more than one group of astronomers. This is evidenced by the recent discovery of another of the most distant galaxies with an apparent magnitude of 20.19. This became possible thanks to the implementation of a pre-planned program to search for ultra-distant galaxies with weak radiation in the vicinity of other already known celestial bodies, including quasars (quasi-stellar sources of radio emission), which emit many times more energy than the most powerful galaxies. The record holder galaxy was discovered near the quasar PKS 1614+051 with a redshift Z = 3.209. Light radiation from it was emitted when the Universe was. three times younger than now.

The most distant star in our galaxy

A team of astronomers from the University of Washington has discovered the most distant star in our galaxy - an 18-magnitude red giant. This star is located in the direction of the constellation Libra and is removed from the Earth at a distance that light can overcome in 400 thousand years. It is clear that this star is located near the boundary line, in the so-called zone of the galactic halo. After all, the distance to this star is approximately 4 times the diameter of the imaginary expanses of our Galaxy. (The diameter of the Milky Way is estimated at about 100 thousand light years.) It is surprising that the most distant, rather bright star was discovered only in our time, although it was observed earlier. For incomprehensible reasons, astronomers did not pay much attention to the faintly luminous spot in the starry sky and which differs on the photographic plate. What happens? People see a star for a quarter of a century and ... do not notice it. More recently, American astronomers from the Lowell Observatory discovered another of the most distant stars in the peripheral limits of our Galaxy. This star, already dimmed from "old age", can be searched in the sky in the location of the constellation Virgo, at a distance of about 160 thousand light years. Such discoveries in the dark (in the literal and figurative sense of the word) parts of the Milky Way make it possible to make important adjustments in determining the true values ​​​​of the mass and size of our star system in the direction of their significant increase. And this can seriously affect the cosmological picture of the universe accepted in the scientific community.

The most open star cluster

Of all the star clusters, the most scattered in outer space is the collection of stars, called the "Veronica's Hair". The stars here are scattered at such great distances from each other that they are seen as cranes flying in a chain. Therefore, the constellation, which is an ornament of the starry sky, is also called the "Wedge of the Flying Cranes."

Superdense clusters of galaxies

It is known that the Milky Way galaxy, together with the solar system, is located in a spiral galaxy, which in turn is part of a system formed by a cluster of galaxies. There are many such clusters in the Universe. I wonder which cluster of galaxies is the densest and largest? According to scientific publications, scientists have long suspected the existence of giant supersystems of galaxies. IN Lately The problem of superclusters of galaxies in the limited space of the Universe attracts more and more attention of researchers. And first of all, because the study of this issue can provide additional important information about the birth and nature of galaxies and radically change the existing ideas about the origin of the Universe.

Over the past few years, giant star clusters have been discovered in the sky. The densest cluster of galaxies in a relatively small area of ​​\u200b\u200bspace was recorded by the American astronomer L. Cowie from the University of Hawaii. From us, this supercluster of galaxies is located at a distance of 5 billion light years. It radiates as much energy as several trillion celestial bodies like the Sun combined can generate.

At the beginning of 1990, American astronomers M. Keller and J. Hykre discovered a superdense cluster of galaxies, which was given the name "Great Wall", by analogy with the Great Wall of China. The length of this stellar wall is approximately 500 million light years, and the width and thickness are 200 and 50 million light years, respectively. The formation of such a star cluster does not fit into the generally accepted big bang theory of the origin of the Universe, from which the relative uniformity of the distribution of matter in space follows. This discovery posed a rather difficult task for scientists.

It should be noted that the closest clusters of galaxies to us are located in the constellations of Pegasus and Pisces at a distance of only 212 million light years. But why are galaxies located at a greater distance from us in denser layers relative to each other than in parts of the Universe closest to us, as expected? Above this difficult question still puzzle astrophysicists.

closest star cluster

The closest open star cluster to the solar system is the famous Hyades in the constellation Taurus. Against the background of the winter starry sky, it looks good and is recognized as one of the most wonderful creations of nature. Of all the star clusters in the northern starry sky, the constellation Orion is best distinguished. It is there that some of the brightest stars are located, including the star Rigel, located at a distance of 820 light years from us.

Supermassive black hole

Black holes often involve nearby cosmic bodies in rotational motion around them. An unusually fast rotation of astronomical objects around the center of the Galaxy, which is 300 million light-years away from us, was discovered quite recently. By expert opinion, such an ultra-high speed of rotation of bodies is due to the presence in this part of the world space of a supermassive black hole, the mass of which is equal to the mass of all the bodies of the Galaxy taken together (approximately 1.4x1011 masses of the Sun). But the fact is that such a mass is concentrated in a part of space 10 thousand times smaller than our star system, the Milky Way. This astronomical discovery so impressed American astrophysicists that it was decided to immediately begin a comprehensive study of a supermassive black hole, the radiation of which is closed in itself by powerful gravity. To do this, it is planned to use the capabilities of an automatic gamma-ray observatory launched into near-Earth orbit. Perhaps such decisiveness of scientists in the study of the mysteries of astronomical science will finally reveal the nature of the mysterious black holes.

largest astronomical object

The largest astronomical object in the Universe is marked in the star catalogs under the number 3C 345, registered in the early 80s. This quasar is located at a distance of 5 billion light years from Earth. German astronomers using a 100-meter radio telescope and a fundamentally new type of radio frequency receiver measured such a distant object in the Universe. The results were so unexpected that scientists at first did not believe them. No joke, the quasar was 78 million light-years across. Despite such a large distance from us, the object is observed to be twice as large as the lunar disk.

The largest galaxy

Australian astronomer D. Malin in 1985, while studying a section of the starry sky in the direction of the constellation Virgo, discovered a new galaxy. But on this D. Malin considered his mission completed. Only after the rediscovery of this galaxy by American astrophysicists in 1987, it turned out that it was a spiral galaxy, the largest and at the same time the darkest of all known to science at that time.

Located at a distance of 715 million light years from us, it has a cross-sectional length of 770 thousand light years, almost 8 times the diameter of the Milky Way. The luminosity of this galaxy is 100 times less than the luminosity of ordinary spiral galaxies.

However, as the subsequent development of astronomy showed, a larger galaxy was listed in the star catalogs. From the vast class of low-luminosity formations in the Metagalaxy, called the Markarian galaxy, galaxy number 348, discovered a quarter of a century ago, was singled out. But then the size of the galaxy was clearly underestimated. Later observations by American astronomers using a radio telescope located in Socorro, New Mexico, made it possible to establish its true dimensions. The record holder has a diameter of 1.3 million light years, which is already 13 times the diameter of the Milky Way. It is 300 million light years away from us.

The biggest star

At one time, Abell compiled a Catalog of galactic clusters, consisting of 2712 units. According to him, in the galaxy cluster number 2029, right in the center, the largest galaxy in the Universe was discovered. Its size in diameter is 60 times larger than the Milky Way and is about 6 million light years, and the radiation is over a quarter of the total radiation of the galaxy cluster. Astronomers from the US have recently discovered a very large star. Research is still ongoing, but it is already known that a new record holder has appeared in the universe. According to preliminary results, the size of this star is 3500 times larger than the size of our star. And it radiates 40 times more energy than the hottest stars in the universe.

brightest astronomical object

In 1984, the German astronomer G. Kuhr and his colleagues discovered such a dazzling quasar (a quasi-stellar source of radio emission) in the starry sky that even at a great distance from our planet, calculated by many hundreds of light years, it would not yield to the Sun in the intensity of light radiation sent to Earth, although distant from us by outer space, which light can overcome in 10 billion years. In its brightness, this quasar is not inferior to the brightness of the usual 10 thousand galaxies taken together. In the star catalog, he received the number S 50014 + 81 and is considered the brightest astronomical object in the boundless expanses of the Universe. Despite its relatively small size, reaching several light-years in diameter, a quasar radiates much more energy than an entire giant galaxy. If the value of the radio emission of an ordinary galaxy is 10 J/s, and the optical radiation is 10 , then for a quasar these values ​​are respectively equal to 10 and 10 J/s. Note that the nature of the quasar has not yet been clarified, although there are different hypotheses: quasars are either the remains of dead galaxies, or, on the contrary, objects initial stage the evolution of galaxies, or whatever else is completely new.

The brightest stars

According to the information that has come down to us, the ancient Greek astronomer Hipparchus first began to distinguish stars by their brightness in the 2nd century BC. e. To assess the luminosity of different stars, he divided them into 6 degrees, introducing into use the concept of magnitude. In the very early XVII century, the German astronomer I. Bayer proposed to designate the degree of brightness of stars in different constellations with the letters of the Greek alphabet. The brightest stars were called "alpha" of such and such a constellation, the next in brightness - "beta", etc.

The brightest stars in our visible sky are the stars Deneb from the constellation Cygnus and Rigel from the constellation Orion. The luminosity of each of them exceeds the luminosity of the Sun by 72.5 thousand and 55 thousand times, respectively, and the distance from us is 1600 and 820 light years.

In the constellation Orion is another brightest star - the third largest luminosity star Betelgeuse. According to the strength of light emission, it is 22 thousand times brighter than sunlight. Most of the bright stars, although their brightness periodically changes, are collected in the constellation Orion.

The star Sirius from the constellation Canis Major, which is considered the brightest among the stars closest to us, is only 23.5 times brighter than our luminary; its distance is 8.6 light years. There are brighter stars in the same constellation. So, the star of Adara shines like 8700 Suns combined at a distance of 650 light years. And the North Star, which for some reason was incorrectly considered the brightest visible star and which is located at the tip of Ursa Minor at a distance of 780 light years from us, shines only 6000 times brighter than the sun.

The zodiac constellation Taurus is notable for the fact that it contains an unusual star, which is distinguished by its supergiant density and relatively small spherical magnitude. As the astrophysicists have found out, it mainly consists of fast neutrons flying apart in different sides. This star for some time was considered the brightest in the universe.

In general, blue stars have the highest luminosity. The brightest of all known is the star UW CMa, which shines 860 thousand times brighter than the Sun. Stars can change in brightness over time. Therefore, the star-record holder in brightness may also change. For example, reading an old chronicle dated July 4, 1054, you can find out that the brightest star shone in the constellation Taurus, which was visible to the naked eye even during the day. But over time, it began to fade and after a year it disappeared altogether. Soon, in the place where the star shone brightly, they began to distinguish a nebula, very similar to a crab. Hence the name - the Crab Nebula, which was born as a result of a supernova explosion. Modern astronomers in the center of this nebula have discovered a powerful source of radio emission, the so-called pulsar. He is the remnant of that bright supernova described in the old chronicle.

the brightest star in the universe is the blue star UW CMa;
the brightest star in the visible sky is Deneb;
the brightest of the nearest stars is Sirius;
the brightest star in the Northern Hemisphere is Arcturus;
the brightest star in our northern sky is Vega;
the brightest planet in the solar system is Venus;
The brightest minor planet is Vesta.

dimmest star

Of the many faint fading stars scattered throughout outer space, the dimmest is located at a distance of 68 light-years from our planet. If in size this star is 20 times smaller than the Sun, then in luminosity it is already 20 thousand times smaller. The previous record holder emitted 30% more light.

First evidence of a supernova explosion

Astronomers call supernovae stellar objects that suddenly flash and reach their maximum luminosity in a relatively short period of time. It has been established that the oldest evidence of a supernova explosion from all surviving astronomical observations refers to XIV century BC e. Then the ancient Chinese thinkers registered the birth of a supernova and indicated on the shell of a large turtle its location and the time of the outbreak. For modern researchers It was possible to determine the place in the Universe from the armored manuscript, where a powerful source of gamma radiation is currently located. It is hoped that such ancient evidence will help to fully understand the problems associated with supernovae and trace the evolutionary path of special stars in the universe. Such evidence plays important role V modern interpretation the nature of the birth and death of stars.

The shortest living star

The discovery by a group of Australian astronomers led by C. McCarren in the 70s of a new type of X-ray star in the region of the constellations of the Southern Cross and Centaurus made a lot of noise. The fact is that scientists were witnesses of the birth and star death, whose life expectancy was unprecedented a short time- about 2 years. This has never happened before in the history of astronomy. The suddenly flaring star lost its brilliance in a negligible time for stellar processes.

The most ancient stars

Astrophysicists from the Netherlands have developed a new, more advanced method for determining the age of the oldest stars in our galaxy. It turns out that after the so-called big bang and the formation of the first stars in the universe took only 12 billion light years, i.e., much less time than hitherto thought. How correct these scientists are in their judgments, time will tell.

The youngest star

According to scientists from the UK, Germany and the US, conducting joint research, the youngest stars are located in the nebula NGC 1333. This nebula is located at a distance of 1100 light years from us. It has attracted increased attention of astrophysicists since 1983 as the most convenient object of observation, the study of which will reveal the mechanism of star birth. Sufficiently reliable data from the infrared satellite "IRAS" confirmed the guesses of astronomers about the ongoing turbulent processes characteristic of the early stages of star formation. At least a little to the south of this nebula, 7 of the brightest stellar origins were recorded. Among them, the youngest was identified, called "IRAS-4". His age turned out to be quite "infantile": only a few thousand years. It will take many more hundreds of thousands of years for the star to reach the stage of its ripening, when conditions will be created in its core for the raging flow of nuclear chain reactions.

The smallest star

In 1986, mainly by American astronomers from the KittPeak Observatory, a previously unknown star was discovered in our Galaxy, designated LHS 2924, whose mass is 20 times less than that of the Sun, and the luminosity is less than six orders of magnitude. This star is the smallest in our galaxy. Light emission from it arises as a result of the resulting thermonuclear reaction of the conversion of hydrogen into helium.

The fastest star

In early 1993, a message was received from Cornell University that an unusually fast moving stellar object had been discovered in the depths of the Universe, which received the number PSR 2224 + 65 in the star catalog. When meeting in absentia with a new star, the discoverers faced two features at once. Firstly, it turned out to be not round in shape, but guitar-shaped. Secondly, this star moved in outer space at a speed of 3.6 million km / h, which far exceeds all other known stellar speeds. The speed of the newly discovered star is 100 times the speed of our star. This star is at such a distance from us that if it moved towards us, it could cover it in 100 million years.

The fastest rotations of astronomical objects

In nature, pulsars rotate the fastest - pulsating sources of radio emission. The speed of their rotation is so huge that the light emitted by them is focused into a thin conical beam, which an earthly observer can register at regular intervals. The course of atomic clocks can be verified with the greatest accuracy by means of pulsar radio emissions. The fastest astronomical object was discovered by a group of American astronomers at the end of 1982 using a large radio telescope in Arecibo on the island of Puerto Rico. This is a superfast rotating pulsar with the designation PSR 1937+215, located in the constellation Vulpecula at a distance of 16 thousand light years. In general, pulsars have been known to mankind for only a quarter of a century. They were first discovered in 1967 by a group of British astronomers led by Nobel Laureate E. Hewisham as sources of pulsating with high accuracy electromagnetic radiation. The nature of pulsars is not fully understood, but many experts believe that these are neutron stars rapidly rotating around their own axis, exciting strong magnetic fields. But the newly discovered pulsar-record holder rotates at a frequency of 642 rpm. The previous record belonged to a pulsar from the center of the Crab Nebula, which emitted strictly periodic pulses of radio emission with a period of 0.033 rpm. If other pulsars usually emit waves in the radio range from meter to centimeter, then this pulsar also emits in the X-ray and gamma ranges. And it was this pulsar that was first discovered to slow down its pulsation. Recently, the joint efforts of researchers from the European Space Agency and the famous Los Alamos scientific laboratory When studying the X-ray emission of stars, a new binary star system was discovered. Scientists were most interested in the unusually fast rotation of its components around its center. The distance between the celestial bodies included in the stellar pair was also record close. At the same time, the emerging powerful gravitational field includes a nearby white dwarf in its sphere of action, thereby forcing it to rotate at an enormous speed - 1200 km / s. The X-ray intensity of this pair of stars is about 10 thousand times higher than that of the Sun.

Top speeds

Until recently, it was believed that the limiting speed of propagation of any physical interactions is the speed of light. Above the speed of movement, equal to 299 792 458 m/s, with which light propagates in a vacuum, according to experts, in nature should not be. This follows from Einstein's theory of relativity. True, in recent times many prestigious scientific centers have begun to declare more and more often about the existence of superluminal motions in the world space. For the first time, superluminal data were obtained by American astrophysicists R. Walker and J. M. Benson in 1987. When observing the radio source ZS 120, located at a considerable distance from the nucleus of the Galaxy, these researchers recorded the speed of movement of individual elements of the radio structure, which exceeded the speed of light. Careful analysis of the combined radio map of the source ZS 120 gave a linear velocity value of 3.7 ± 1.2 of the speed of light. Scientists have not yet operated with large values ​​of movement speeds.

The strongest gravitational lens in the universe

The phenomenon of the gravitational lens was predicted by Einstein. It creates the illusion of a double image of an astronomical object of radiation by means of a powerful gravitational field source in the way, which bends the rays of light. Einstein's hypothesis was first confirmed in 1979. Since then, a dozen gravitational lenses have been discovered. The strongest of them was discovered in March 1986 by American astrophysicists from the KittPyk observatory headed by E. Turner. When observing one quasar, distant from the Earth at a distance of 5 billion light years, its bifurcation was recorded, separated by 157 arc seconds. This is a fantastic lot. Suffice it to say that other gravitational lenses lead to a bifurcation of the image with a length of no more than seven arcseconds. Apparently, the reason for such a colossal bifurcation of the image is a supermassive black hole, which is 1000 times heavier than our Galaxy, as a result of which a powerful gravitational field is created in this part of the Universe.

The most powerful magnet in the universe

The strongest magnetic field in the Universe is formed in the vicinity of a fifteenth-magnitude star under the astronomical designation PG 1031+234. This is a white dwarf about the same size as the Earth, but separated from the star at a distance of 100 light years. American astrophysicists from the University of Arizona in the mid-80s determined the magnitude of the magnetic induction in this region of space and ... could not believe it. The instrument readings were at the level of 70 thousand Tesla, or in Gaussian units - 700 million. Such a strong magnetic field has not yet been observed in the universe.

Unique gas and dust clouds in space

In the late 70s, information appeared in the press about the discovery of a giant gas and dust cloud in interstellar space. According to scientists, the mass of this cloud is a trillion times the mass of the Sun (1.9889x1030 kg). This is the largest gas and dust cloud in the Universe. And the brightest gas and dust cloud in interstellar space is the Orion Nebula. The mass of the superhot gas cloud exceeds the mass of the Sun by 300 times, and it is located at a distance of about 1.5 thousand light years from us.

The largest hydrogen cloud in the universe

An impressively large cloud of neutral hydrogen was discovered in the Universe quite by accident while solving other astronomical problems in Arecibo by American astronomers from Cornell University. In diameter, this cloud is 10 times larger than our Galaxy, and the hydrogen mass in the cloud is almost a billion times greater than the mass of our star. The cloud is located towards the constellation Leo at a distance of 65 million light years from Earth and rotates around the center of mass at a speed of 80 km/s. As scientists suggest, the birth of a new galaxy is possible from this giant hydrogen cloud. Thus, such a widespread theory of the big bang about the simultaneous birth of all galaxies after a colossal explosion in the Universe falls into doubt.

The most common substance in interstellar space

More than 60 molecules have been identified in the lifeless interstellar medium chemical substances. Most of all in interstellar space hydrogen. In terms of abundance, hydrogen is far ahead of the total content of all other chemical elements. If we take the hydrogen content as a unit, then the relative content of helium will be 0.09, oxygen - 0.0007, carbon - 0.0003, nitrogen - 0.00009.

The densest clusters of astronomical objects

Black holes are the densest clusters of astronomical objects. The densest clusters of space objects are the so-called black holes, predicted by the theory of relativity. In outer space, the appearance of black holes occurs as a result of the colossal gravitational compression of supermassive astronomical objects. The compression is so strong that the resulting gravitational field does not release even light emission from its zone of influence. According to astrophysicists, the cosmic density in black holes reaches 5x10 Mg/m. This is such a huge value that it is difficult to imagine or compare with the measured values ​​in nature. For comparison: the density of a neutron star and the density of an atomic nucleus is 10.4 Mg/m, while the density of the Sun is only 1.4 Mg/m. The average density in an ordinary galaxy is 2x1 Mg/m, and in the entire Universe it is presumably 10 Mg/m.

Mercury - on this moment considered the smallest of all known planets located in the solar system.

It rotates around the Sun at a distance of 47 million km along a highly elongated elliptical orbit with an average speed of 48 km/s. There is relatively little information about this planet today, this is due to the fact that Mercury is located very close to the Sun, and this greatly complicates the process of its study.

Global map of Mercury, compiled using the MESSENGER spacecraft

Record temperature drops

This smallest planet in the solar system has the largest temperature differences on the surface of all known in this system. This is due to the close proximity to the Sun, the absence of an atmosphere, and the relatively slow rotation of the planet itself. Its average daytime temperature is approximately 350 °C above zero, and at night around 170 °C below zero. The minimum recorded temperature on Mercury is minus 183 °C, and the maximum, reached in the middle of the day at “hot longitudes” when the planet is located near the perihelion, is plus 427 °C. Despite these conditions, modern scientists have put forward an assumption about the existence of ice on the surface of Mercury.

Small but distant...

Mercury is also the smallest planet in the terrestrial group. Its circumference is only 4879.4 ± 1.0 km, which is less than the circumference of Ganymede - the satellite of Jupiter and Titan - the satellite of Saturn. But, despite its much smaller size, due to its huge core, the smallest planet still surpasses these satellites of the giant planets in its mass, which is 3.3 × 10 to the 23rd power of kg. The value of the average density of relatively small Mercury is slightly less than the density of the much larger Earth and is 5.43 g / cm³, thus indicating a high content of metals in its bowels.

There is no atmosphere, and never was

According to the characteristics of the surface, Mercury is practically a twin of the Moon, it is also very heavily covered with numerous craters, but at the same time its surface is absolutely homogeneous, which serves as its hallmark from the Moon or Mars, which have a strong difference of one hemisphere from the other. The lack of surface erosion almost completely rules out theories that Mercury ever had a significant atmosphere. According to available data, at present the pressure of the atmosphere of this planet is 5 × 10 to 11 times less than the pressure of the Earth's atmosphere.

Refutation of the presence of a metal core in Mercury

Canyon on Mercury. Surprising details sometimes helps to bring out the lighting

Until recently, scientists believed that Mercury consists of a metal core with a radius of approximately 1900 km, located in the bowels and forming 60% of the entire mass of the planet, and the surface of this core is covered by a silicate shell approximately 600 km thick. These assumptions were made due to the fact that a very weak magnetic field was discovered during the study, and it was believed that a planet of such small sizes could not have a liquid core.

But already in 2007, a team of leading astronomers led by Jean-Luc Margot, after analyzing the results of five years of radar observations of this space object, during which too large rotation variations were found for a planet with a solid core, refuted this theory.

Non-fiction film about Mercury from the European Space Agency