INSTRUCTIONS AND PROPHECIES OF THE Blessed MOTHER ALIPIA GOLOSEEVSKY, Kyiv...
Lifeless space is not deserted at all. It combines a huge mass of all kinds of bodies of different nature, sizes and with different name. Among them are meteors, meteorites, comets, fireballs, planets and stars. Moreover, each of the categories of cosmic bodies within itself is also divided into types, the difference between which can often be understood only by an experienced astronomer. For now, let's try to understand the fundamental principles, for example, how stars differ from planets.
Main difference
The very first, basic and undeniable difference is the ability to glow. Any star necessarily emits light, but the planet does not have this property. Of course, nearby planets also look like luminous specks - Venus can serve as an eloquent example. But this is not her own glow, she is just a "mirror", which reflects the light of the true source - the Sun.
By the way, this is very good way how to distinguish a planet from a star purely visually, without additional optical instruments. If a luminous dot in the night sky “winks”, that is, flickers, you can be sure that this is a star. If the light emanating from a celestial object is even and constant, then it reflects the light of the nearest luminary. And this is the very first and clear sign showing us how the stars differ from the planets.
The second difference stemming from the first
The ability to emit light is characteristic only of very hot surfaces. As an example, consider a metal that does not glow by itself. But if it is heated to desired temperature, a metal object is heated and radiates, albeit weak, but light.
So the second thing that distinguishes stars from planets is the very high temperature of these cosmic bodies. This is what makes the stars glow. Even on the surface of the coldest star, the temperature does not fall below 2000 degrees K. Usually, stellar temperatures are measured in Kelvin, in contrast to the Celsius familiar to us.
Our Sun is much hotter, at different periods its surface heats up to 5000 or even 6000 K. That is, “in our opinion” it will be 4726.85 - 5726.85 ° C, which is also impressive.
Necessary clarification
These temperatures are typical only for stellar surfaces. Another way stars differ from planets is that they are much hotter inside than outside. Even the surface temperatures on some stars reach 6000 K, and in the center of the stars they presumably go off scale for millions of degrees Celsius! So far, there are no opportunities, no necessary equipment, not even a calculation formula with which it would be possible to determine the internal "degrees" of stars.
Dimensions and movement
The sizes of stars and planets differ just as grandiosely. Compared to the heavenly "lanterns", the planets are just grains of sand. And this applies to both weight (mass) and volume. If, instead of the Sun, a medium-sized apple is placed in the middle of free space, then a pea, placed hundreds of meters away, will be needed to indicate the position of the Earth. A comparison of the stars also shows that the volumes of the latter are thousands or even millions of times greater than the volume in space occupied by the former. With a mass of dumb other ratios. The fact is that all the planets are solid bodies. And the stars are mostly gaseous, otherwise, with which the sky-high temperatures of the luminaries are provided, they would simply be impossible.
What is the difference between a planet and a star? A planet, by definition, has a trajectory of motion called an orbit. And it necessarily surrounds the star as more weighty. The star is motionless in the sky. If you have patience and follow a certain part of the sky for several nights, the movement of the planet can be seen even with a weakly armed eye (but at least you won’t be able to do without an amateur telescope).
Additional features
The sizes of stars and planets cannot be determined by eye. But some differences that accurately characterize require even more specific equipment. So, chemical composition, which is available to determine by exactly what the planet or star is in front of us. After all, the luminaries are gaseous giants, therefore, they consist of light elements. And the planets include mostly solid components.
An indirect sign may be the presence of a satellite (or even several). They are only found on planets. However, if a satellite is not observed, this does not mean at all that we have a star in front of us - some planets do well without such "neighbors".
Astronomers have another sign of determining whether a newly discovered cosmic body is a planet. The orbit along which it moves should not contain foreign objects, roughly speaking, debris. Satellites are not considered as such, they are quite large in size, otherwise they would have fallen to the surface. This rule was adopted quite recently - in 2006. Thanks to him, Eris, Ceres and - attention! - Pluto is now considered not full, but
Astronomical calculations
Scientists are highly inquisitive. Knowing perfectly well how stars differ from planets, they nevertheless wondered what would happen when the massiveness of the planet exceeded, for example, the size of the Sun. It turned out that such an increase in the size of the planet will lead to a sharp increase in pressure in the core cosmic body; then the temperature will reach a million (or several) degrees; nuclear and thermonuclear reactions will begin - and instead of a planet, we will get a newborn star.
The first exoplanet discovered was the planet around the star 51Peg in the constellation Pegasus. In fact, the planet around the star 51Peg was discovered in 1994, but it was officially announced only in the fall of the following year. Reports of the discovery of planets appeared before, during almost the entire second half of the twentieth century, but were invariably refuted. In fairness, we should start with the classic (and longest) history of the search for hypothetical planets around Barnard's ("flying") star, discovered in 1916.
Barnard's Star is the fourth of the closest stars to the Sun. In astrophysics, stars are classified into types, depending mainly on their temperature. The Sun is a G2 class star with a radiation temperature of about 6000 K. Barnard's Star is a relatively cold and low-mass red dwarf of the late M5V class. E. Barnard was a comet hunter, and not disinterested: the US government then paid bonuses for finds of comets. He discovered his star in 1916 by accident, thanks to its main feature - a large visible movement across the sky, about 10 arc seconds per year. Later, another researcher from the USA, P. Van de Kamp, became interested in Barnard's star and did not stop its research for more than half a century. He began to study the motion of a star in 1938 using the astrometric method ( precise definition coordinates of the object and its position relative to other stars), and, accumulating observational material, persistently continued this work until the 1980s. Van de Kamp used photographic plates of his observations on the 61-cm telescope of the American Sproul Observatory, most of which he made in 1950-1978. Based on the results of an astrometric analysis of 2400 images, Van de Kamp found that the trace of Barnard's star on a photographic plate forms a weakly wavy line with an oscillation range of up to 0.0005 mm, which corresponds to a periodic displacement of the star by 0.04 arc seconds. Such fluctuations could arise under the influence of a massive planet revolving around the star, since in reality both bodies revolve around a common center of mass, which, of course, is much closer from the center of the star than from the center of the planet (as much closer as the mass stars are larger than the mass of the planet). In the same balance are, say, a grandmother and granddaughter, swinging at opposite ends of the board. So that none of them outweighs, the support of the board (barycenter) should be much closer to the massive grandmother than to the light granddaughter. The star and the planet do not wobble, but revolve around the barycenter, but its position is determined by the same condition. The more massive the planet and the smaller the mass of the star, the more noticeable should be periodic fluctuations in the movement of the latter. Since Barnard's star is moving rapidly, the individual points of its successive positions add up to a slightly wavy trail, Van de Kamp believed (see "Science and Life" No. 9, 1973).
It followed from Van de Kamp's data that perturbations in the motion of a star are caused by a planet with the mass of Jupiter (or more) and approximately with its orbit. Subsequently, de Camp spoke of two planets, with periods of 12 and 26 years. The popularity of de Camp's research grew, helped by the fact that he knew how to master the audience well. However, some skeptics were suspicious of his data.
N. Wegman, one of de Camp's close colleagues, carried out independent measurements, found no fluctuations in the position of Barnard's star, but did not publish his results. In 1971, D. Gatewood, who was then a graduate student at the Allegheny Observatory (USA), was asked to investigate the movements of Barnard's star as a dissertation topic. Computers were just entering astronomical practice at that time, but Gatewood managed to develop a new astrometric instrument - a multichannel computerized photometer, which largely excluded possible mistakes measurements. For reliability, the measurements were carried out independently at two observatories. When a sufficient number of images had accumulated, the program for processing them was launched. All participants in the work gathered around the bulky, rumbling printer. “It was a strange case, it all happened so quickly, in minutes,” Gatewood said. “We looked at the printout crawling out of the printer, and we didn’t know which of the stars was Barnard. And then a star appeared with disturbances about 30 thousandths of an arc second. I brightened up. My God, here it is! We found it! Fantastic! We crowded, looking, discussing, and then ... then I saw the number of the star. This was not Barnard's Star! It was a binary star with a perturbing companion. "Next, a completely even, without any waviness, trace of Barnard's star appeared.
De Camp insisted until the end of his days on the existence of planets around Barnard's star. He died in 1995, a year that oddly coincided with the discovery of the first genuine exoplanet around the star 51Peg.
Along with astrometry, the researchers considered other possible methods for finding planets. The reviews of the 1980s provided well-founded assessments of the possibilities of the radial velocity methods (more on that below) and observations of extrasolar planetary bodies in the optical and infrared ranges.
The method of direct photometric registration of exoplanets by their reflected light was discussed by many researchers in the 1970s–1990s. The author in one of his works in 1986 considered the feasibility of such a registration of planets, based on the very, very limiting technical capabilities. It was assumed that the planetary system is similar to the solar system observed from a distance of 5 pc. The ratio of the light reflected by the planet to the light of the Sun is very small and amounts to one billionth for Venus and Jupiter, and four times less for the Earth. The ideal optical system of a space telescope with a diameter of 2.6 meters with an ideal receiver could create a photocurrent of 10-20 photoelectrons per second from the light of Jupiter. In principle, such a current can be measured, but the photocurrent registration noise from the star itself exceeds these values by a factor of 10,000, so the system must be very complex. Calculations showed that the task requires an exposure time of at least 10 hours.
The technical difficulties of the direct registration method were the reason for the skepticism towards it. Theoretically, the radiometric method has great advantages, which differs from the photometric method only in the range of wavelengths. The trick here is to use the features of the Planck blackbody radiation curve. It is not reflected light that is recorded, but the planet's own infrared radiation in the range of 25-50 microns. The wavelength is chosen to the right of the maximum of the Planck curve for the planet, where the gain is greatest. In addition, unlike optical photometry, thermal radiation comes from the entire surface of the planet, and not just from the illuminated side. Taking into account the properties of the Planck equation, the intensity ratio infrared radiation Jupiter and the Sun is 150 thousand times greater than the ratio of their brightness in the optical range. But the real win, for technical reasons, does not exceed 100 times.
The effectiveness of the method of direct registration (in the optical range) was nevertheless proved by observations of the planet around the so-called brown dwarf 2M1207. This is a special case, which is discussed below.
Distribution of radiation intensity in the spectrum of a black body. If in the visible region the ratio of the brightness of a star and a planet reaches tens of billions, then in the Rayleigh region-Jeans- only about a hundred.
White object on the right- it is a "brown" (infrared) dwarf 2M1207. Apparently, this dwarf star has a planet (on the left in the picture). Mass of the planet- about five masses of Jupiter; it is at a distance of 55 AU.- 10 times farther from the star than Jupiter is from the Sun. (The image was taken at the South European Paranal Observatory (Chile) using the so-called adaptive optics 8-meter telescope.)
Good visibility on a clear night.
planets
Among the countless stars can be easily distinguished by their brilliance planets, which is translated from ancient Greek - wandering stars. These celestial bodies were so named by the ancient Greeks because from day to day they moved relative to the seemingly motionless stars and in the night sky seemed to be bright luminaries.
Planets of the Universe
As you know, the planets are not at all: they receive light from and move around it in orbits that are close to a circle in shape.
Comets
In very elongated orbits, after one or another period of time, distant guests of our planet fly from interplanetary spaces. solar system - comets, or tailed stars(translated from Greek). The sudden appearance of a comet has always frightened the ignorant man.
They talked about the devastating bloody wars, troubles, famine, pestilence will go everywhere, and even the end of the world will come.
Much more often can be observed, especially at the end of summer, august star shower. In the old days, it was believed that every person has his own star in the sky, and when he dies, his star also fades, falls.
The stars certainly don't fall. This is the wreckage celestial bodies and decayed comets: they heat up to several thousand degrees and begin to glow, once they enter the earth's atmosphere.
meteorites
The hot air around the falling bodies also glows. In the event that they do not completely burn out, turning into a hot gas, they fall to the ground heavenly stones, as they used to be called, or meteorites. Sometimes they reach enormous sizes.
The meteorite, which fell in February 1947 in the area of the Sikhote-Alin ridge with a rain of fragments, is believed to have weighed up to one hundred tons. At the site of its fall, I found many deep craters up to 30 meters in diameter. For two years, about 23 tons of meteorite fragments were collected in this area.
The famous Tunguska meteorite, which fell in the summer of 1908 in the remote taiga, near the small village of Vinovara near the river. Podkamennaya Tunguska ( Krasnoyarsk region), has not yet been found, despite many years of searching. Scientists believe that it exploded on impact and completely disintegrated into tiny particles metal dust.
It was indeed discovered during the analysis of the soil in the area of the explosion, which was heard for 1000 kilometers. The explosion column rose to a height of at least 20 kilometers and was visible for 750 kilometers in a circle. On a huge area - up to 60 kilometers in diameter - trees were felled, their tops in all directions from the explosion site.
Scientists believe that about 10 tons of meteorite material falls on Earth every day.
Usually, among the dimly twinkling stars, one can distinguish brighter ones - bluish-white, yellow, reddish. Most stars in a wide silver band - Milky Way, which, like a giant hoop, encircles the vault of heaven.
With his penetrating gaze, man penetrated the innermost depths of the universe and finally saw, through powerful telescopes, distant worlds like the Milky Way. It is not difficult to conclude from this what a modest place ours occupies in the universe - infinite in time and space, having neither beginning nor end.
Star - a hot self-luminous ball
On strict astronomical accounting - millions. The stars and planets of the Universe, as they say, are individually counted, entered into special lists, into a catalog, marked on special maps.
Each star - a hot self-luminous ball similar to our sun.
Star Sun The stars are very far from us. To the nearest star, that's what it's called Proxima, i.e., in Latin, the nearest, - it would take a very, very long time to get even with the help of a rocket. The light from this star to Earth takes four years, according to astronomers.
The speed of light is very high, 300,000 kilometers per second! From this we can draw the following conclusion, if, say, Proxima will fade today, people will observe its last ray in the sky for four whole years.
One hundred and fifty million kilometers separating from, light travels in 8 minutes 18 seconds. How close to us is the Sun compared to its closest neighbor!
The size of the stars is very different. The giant star (from the constellation Cepheus) is 2300 times larger than the Sun, and the baby stars (the Kuiper star) are almost half the size of the Earth.
The temperature of the stars
different and temperature of the stars. The bluish-white stars are the hottest: their surface temperature is 30,000°; on yellow stars it is already cooler - 6000°, and on red stars 3000° and below. Our Sun is a rather weak star, yellow dwarf as astronomers call it.
The birth of the stars
Exploring the heavenly bodies, scientists have made many interesting conclusions about the birth of stars, about their development and chemical composition. The chemical composition of celestial bodies is studied by a special device - a spectroscope. It makes it possible to detect even negligibly small amounts of a substance by the characteristic colored lines of the spectrum.
Spectrum
Spectrum(from the Latin "spectrum") - visible, vision.
An idea of the spectrum can be obtained from the rainbow after the rain. It attracts with subtle transitions from one color to another: from red - through orange, yellow, green, blue and blue - to purple.
You will never forget the place of each color in the spectrum if you remember this little fable:
Every hunter wants to know where the pheasant is sitting.
Here initial words denote color.
When a beam of light passes through a trihedral glass prism and falls on a sheet of paper or a white wall, a beautiful rainbow strip is also obtained. You will see the same colored stripe on the ceiling or wall if a ray of the sun falls on the edge face of the mirror or the light sparkles with color tints on the faceted balls and pendants of the theatrical chandelier.
Hot solid and liquid bodies, as well as gases under high pressure, form continuous spectra in the form of iridescent stripes, while rarefied gases give, when heated, not a continuous, but a linear spectrum; it consists of separate colored lines characteristic of each substance, separated by dark gaps.
The adaptation of the spectroscope to the telescope made it possible to obtain photographs of the spectra of very distant celestial bodies and draw the conclusion from this that not a single chemical element unknown on Earth has yet been found on them. The same results were given by the chemical analysis of meteorites. Spectral analysis of distant stellar worlds and chemical analysis of meteorites speak convincingly of unity of matter in the universe.
The content of the article:
Celestial bodies are objects located in the Observable Universe. Such objects can be natural physical bodies or their associations. All of them are characterized by isolation, and also represent a single structure bound by gravity or electromagnetism. Astronomy is the study of this category. This article brings to attention the classification of the celestial bodies of the solar system, as well as a description of their main characteristics.
Classification of celestial bodies in the solar system
Each celestial body has special characteristics, such as the method of generation, chemical composition, size, etc. This makes it possible to classify objects by grouping them. Let's describe what are the celestial bodies in the solar system: stars, planets, satellites, asteroids, comets, etc.
Classification of the celestial bodies of the solar system by composition:
- silicate celestial bodies. This group celestial bodies is called silicate, because. the main component of all its representatives are stone-metal rocks (about 99% of the total body weight). The silicate component is represented by such refractory substances as silicon, calcium, iron, aluminum, magnesium, sulfur, etc. There are also ice and gas components (water, ice, nitrogen, carbon dioxide, oxygen, helium hydrogen), but their content is negligible. This category includes 4 planets (Venus, Mercury, Earth and Mars), satellites (Moon, Io, Europa, Triton, Phobos, Deimos, Amalthea, etc.), more than a million asteroids circulating between the orbits of two planets - Jupiter and Mars (Pallas , Hygiea, Vesta, Ceres, etc.). The density index is from 3 grams per cubic centimeter or more.
- Ice celestial bodies. This group is the most numerous in the solar system. The main component is the ice component (carbon dioxide, nitrogen, water ice, oxygen, ammonia, methane, etc.). Present in a smaller amount silicate component, and the volume of gas is extremely small. This group includes one planet Pluto, large satellites (Ganymede, Titan, Callisto, Charon, etc.), as well as all comets.
- Combined celestial bodies. The composition of the representatives of this group is characterized by the presence in large quantities all three components, i.e. silicate, gas and ice. Celestial bodies with a combined composition include the Sun and the giant planets (Neptune, Saturn, Jupiter and Uranus). These objects are characterized by fast rotation.
Characteristics of the star Sun
The sun is a star, i.e. is an accumulation of gas with incredible volumes. It has its own gravity (an interaction characterized by attraction), with the help of which all its components are held. Inside any star, and hence inside the Sun, thermonuclear fusion reactions take place, the product of which is colossal energy.
The sun has a core, around which a radiation zone is formed, where energy transfer occurs. This is followed by a convection zone, in which magnetic fields and motion of solar matter. The visible part of the Sun can be called the surface of this star only conditionally. A more correct formulation is the photosphere or sphere of light.
The attraction inside the Sun is so strong that it takes hundreds of thousands of years for a photon from its core to reach the surface of a star. At the same time, its path from the surface of the Sun to the Earth is only 8 minutes. The density and size of the Sun make it possible to attract other objects in the solar system. The free fall acceleration (gravity) in the surface zone is almost 28 m/s 2 .
The characteristic of the celestial body of the star Sun is as follows:
- Chemical composition. The main components of the Sun are helium and hydrogen. Naturally, the star includes other elements, but they specific gravity very scanty.
- Temperature. The temperature value varies significantly in different zones, for example, in the core it reaches 15,000,000 degrees Celsius, and in the visible part - 5,500 degrees Celsius.
- Density. It is 1.409 g / cm 3. The highest density is noted in the core, the lowest - on the surface.
- Weight. If we describe the mass of the Sun without mathematical abbreviations, then the number will look like 1.988.920.000.000.000.000.000.000.000.000 kg.
- Volume. Full value- 1.412.000.000.000.000.000.000.000.000.000 cubic kilograms.
- Diameter. This figure is 1391000 km.
- Radius. The radius of the Sun star is 695500 km.
- Orbit of a celestial body. The sun has its own orbit around the center milky way. A complete revolution takes 226 million years. Scientists' calculations showed that the speed of movement is incredibly high - almost 782,000 kilometers per hour.
Characteristics of the planets of the solar system
Planets are celestial bodies that orbit around a star or its remnants. Big weight allows planets to become rounded under the influence of their own gravity. However, the size and weight are insufficient to start thermonuclear reactions. Let us analyze in more detail the characteristics of the planets using the examples of some representatives of this category that are part of the solar system.
Mars is the second most explored planet. It is the 4th in distance from the Sun. Its dimensions allow it to take 7th place in the ranking of the most voluminous celestial bodies in the solar system. Mars has inner core surrounded by an outer liquid core. Next is the silicate mantle of the planet. And after the intermediate layer comes the crust, which has a different thickness in different parts of the celestial body.
Consider in more detail the characteristics of Mars:
- The chemical composition of the celestial body. The main elements that make up Mars are iron, sulfur, silicates, basalt, iron oxide.
- Temperature. The average is -50°C.
- Density - 3.94 g / cm 3.
- Weight - 641.850.000.000.000.000.000.000 kg.
- Volume - 163.180.000.000 km 3.
- Diameter - 6780 km.
- Radius - 3390 km.
- Acceleration of gravity - 3.711 m / s 2.
- Orbit. Runs around the sun. It has a rounded trajectory, which is far from ideal, because in different time the distance of a celestial body from the center of the solar system has different indicators - 206 and 249 million km.
Pluto has the following characteristics:
- Compound. The main components are stone and ice.
- Temperature. The average temperature on Pluto is -229 degrees Celsius.
- Density - about 2 g per 1 cm 3.
- The mass of the celestial body is 13.105.000.000.000.000.000.000 kg.
- Volume - 7.150.000.000 km 3.
- Diameter - 2374 km.
- Radius - 1187 km.
- Acceleration of gravity - 0.62 m / s 2.
- Orbit. The planet revolves around the Sun, however, the orbit is characterized by eccentricity, i.e. in one period it recedes to 7.4 billion km, in another it approaches 4.4 billion km. The orbital velocity of the celestial body reaches 4.6691 km/s.
The main characteristics of Uranus:
- Chemical composition. This planet is made up of a combination chemical elements. In large quantities, it includes silicon, metals, water, methane, ammonia, hydrogen, etc.
- Celestial body temperature. average temperature- -224°С.
- Density - 1.3 g / cm 3.
- Weight - 86.832.000.000.000.000.000.000 kg.
- Volume - 68.340.000.000 km 3.
- Diameter - 50724 km.
- Radius - 25362 km.
- Acceleration of gravity - 8.69 m / s 2.
- Orbit. The center around which Uranus revolves is also the Sun. The orbit is slightly elongated. The orbital speed is 6.81 km/s.
Characteristics of satellites of celestial bodies
A satellite is an object located in the Visible Universe, which does not revolve around a star, but around another celestial body under the influence of its gravity and along a certain trajectory. Let us describe some satellites and characteristics of these space celestial bodies.
Deimos, a satellite of Mars, which is considered one of the smallest, is described as follows:
- Shape - similar to a triaxial ellipsoid.
- Dimensions - 15x12.2x10.4 km.
- Weight - 1.480.000.000.000.000 kg.
- Density - 1.47 g / cm 3.
- Compound. The composition of the satellite mainly includes stony rocks, regolith. The atmosphere is missing.
- Acceleration of gravity - 0.004 m / s 2.
- Temperature - -40°С.
Characteristics of Callisto:
- The shape is round.
- Diameter - 4820 km.
- Weight - 107.600.000.000.000.000.000.000 kg.
- Density - 1.834 g / cm 3.
- Composition - carbon dioxide, molecular oxygen.
- Acceleration of gravity - 1.24 m / s 2.
- Temperature - -139.2 ° С.
Consider the characteristics of Oberon:
- The shape is round.
- Diameter - 1523 km.
- Weight - 3.014.000.000.000.000.000.000 kg.
- Density - 1.63 g / cm 3.
- Composition - stone, ice, organic.
- Acceleration of gravity - 0.35 m / s 2.
- Temperature - -198°С.
Characteristics of asteroids in the solar system
Asteroids are large boulders. They are mainly located in the asteroid belt between the orbits of Jupiter and Mars. They can leave their orbits towards the Earth and the Sun.
A prominent representative of this class is Hygiea - one of the largest asteroids. This celestial body is located in the main asteroid belt. You can see it even with binoculars, but not always. It is well distinguishable during the period of perihelion, i.e. at the moment when the asteroid is at the point of its orbit closest to the Sun. It has a dull dark surface.
The main characteristics of Hygiea:
- Diameter - 407 km.
- Density - 2.56 g/cm 3 .
- Weight - 90.300.000.000.000.000.000 kg.
- Acceleration of gravity - 0.15 m / s 2.
- orbital speed. The average value is 16.75 km/s.
The main characteristics of Matilda are as follows:
- Diameter - almost 53 km.
- Density - 1.3 g / cm 3.
- Weight - 103.300.000.000.000.000 kg.
- Acceleration of gravity - 0.01 m / s 2.
- Orbit. Matilda completes an orbit in 1572 Earth days.
This asteroid has an iron-nickel core covered with a rocky mantle. The largest crater on Vesta is 460 km long and 13 km deep.
We list the main physical characteristics of Vesta:
- Diameter - 525 km.
- Weight. The value is within 260.000.000.000.000.000.000 kg.
- Density - about 3.46 g/cm 3 .
- Free fall acceleration - 0.22 m / s 2.
- orbital speed. Average orbital speed is equal to 19.35 km/s. One revolution around the Vesta axis takes 5.3 hours.
Characteristics of solar system comets
A comet is a small celestial body. Comets orbit around the Sun and have elongated shape. These objects, approaching the Sun, form a trail consisting of gas and dust. Sometimes he remains in the form of a coma, ie. a cloud that stretches for a huge distance - from 100,000 to 1.4 million km from the comet's nucleus. In other cases, the trail remains in the form of a tail, the length of which can reach 20 million km.
Halley is the celestial body of a group of comets, known to mankind since ancient times, because. it can be seen with the naked eye.
Features of Halley:
- Weight. Approximately equal to 220.000.000.000.000 kg.
- Density - 600 kg / m 3.
- The period of revolution around the Sun is less than 200 years. The approach to the star occurs approximately in 75-76 years.
- Composition - frozen water, metal and silicates.
Composition of the comet: deuterium (heavy water), organic compounds (formic, acetic acid and others), argon, crypto, etc. The period of revolution around the Sun is 2534 years. There are no reliable data on the physical characteristics of this comet.
Comet Tempel is famous for being the first comet to have a probe delivered from Earth.
Characteristics of Comet Tempel:
- Weight - within 79.000.000.000.000 kg.
- Dimensions. Length - 7.6 km, width - 4.9 km.
- Compound. Water, carbon dioxide, organic compounds, etc.
- Orbit. Changes during the passage of a comet near Jupiter, gradually decreasing. Recent data: one revolution around the Sun is 5.52 years.
Over the years of studying the solar system, scientists have collected a lot interesting facts about celestial bodies. Consider those that depend on chemical and physical characteristics:
- The largest celestial body in terms of mass and diameter is the Sun, Jupiter is in second place, and Saturn is in third.
- The greatest gravity is inherent in the Sun, the second place is occupied by Jupiter, and the third - by Neptune.
- Jupiter's gravity contributes to the active attraction of space debris. Its level is so high that the planet is able to pull debris from the Earth's orbit.
- The hottest celestial body in the solar system is the Sun - this is no secret to anyone. But the next indicator of 480 degrees Celsius was recorded on Venus - the second planet farthest from the center. It would be logical to assume that Mercury should have the second place, the orbit of which is closer to the Sun, but in fact the temperature indicator there is lower - 430 ° C. This is due to the presence of Venus and the lack of an atmosphere in Mercury, which is able to retain heat.
- The coldest planet is Uranus.
- To the question of which celestial body has the highest density in the solar system, the answer is simple - the density of the Earth. Mercury is in second place and Venus is in third.
- The trajectory of Mercury's orbit provides the length of a day on the planet equal to 58 Earth days. The duration of one day on Venus is 243 Earth days, while the year lasts only 225.
The study of the characteristics of celestial bodies allows mankind to make interesting discoveries, substantiate certain regularities, as well as expand general knowledge about the Universe.
