Something in your conversation struck a chord:
What is the distance from the Earth to the Sun?
The distance between the Earth and the Sun ranges from 147 to 152 million km. It was possible to measure it very accurately using radars.
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What is a light year?
A light year is a distance of 9460 billion km. This is exactly the path light travels in a year, moving at a constant speed of 300,000 km/s.
How far is it to the moon?
The moon is our neighbor. The distance to it at the point of its orbit closest to Earth is 356,410 km. The maximum distance of the Moon from the Earth is 406697 km. The distance was calculated by the time it took for the laser beam to reach the Moon and return, reflecting from mirrors left on the lunar surface by American astronauts and Soviet lunar probes.
What is parsec?
A parsec is equal to 3.26 light years. Parallax distances are measured in parsecs, that is, distances calculated geometrically from the smallest shifts in the apparent position of a star as the Earth moves around the Sun.
What is the farthest star you can see?
The most distant space objects that can be observed from Earth are quasars. They are located at a distance of 13 billion light years from Earth.
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Are the stars moving away?
Redshift studies show that all galaxies are moving away from ours. The further they go, the faster they move. The most distant galaxies move almost at the speed of light.
How was the distance to the Sun measured for the first time?
In 1672, two astronomers - Cassini in France and Richer in Guiana - noted the exact position of Mars in the sky. They calculated the distance to Mars from the small difference between the two measurements. And then scientists, using elementary geometry, calculated the distance from the Earth to the Sun. The value obtained by Cassini turned out to be underestimated by 7%.
What is the distance to the nearest star?
The closest star to the Solar System is Proxima Centauri, its distance is 4.3 light years, or 40 trillion. km.
How do astronomers measure distances?
What is the distance from the Earth to the Sun?
Sun(hereinafter S.) - the central body of the Solar System, is a hot plasma ball; S. is the closest star to Earth. Weight S. - 1,990 1030 kg(332,958 times the mass of Earth). 99.866% of the mass of the solar system is concentrated in the sun. Solar parallax (the angle at which the equatorial radius of the Earth is visible from the center of the north, located at an average distance from the north, is 8.794 (4.263’10 = 5 rad). The distance from the Earth to the North varies from 1.4710’1011 m (January) to 1.5210’1011 m (July), averaging 1.4960’1011 m(astronomical unit). The average angular diameter of the Earth is 1919.26 (9.305'10 = 3 rad), which corresponds to the linear diameter of the Earth 1.392'109 m (109 times the diameter of the Earth's equator). The average density of the Earth is 1.41'103 kg/ m3. The acceleration of gravity on the surface of the sun is 273.98 m/sec2. The parabolic speed on the surface of the sun (second cosmic velocity) is 6.18'105 m/sec. The effective temperature of the surface of the sun, determined according to the Stefan-Boltzmann law. radiation, according to the total radiation of the sun (see Solar radiation), is equal to 5770 K.
The history of telescopic observations of S. begins with observations made by G. Galileo in 1611; Sunspots were discovered, and the period of revolution of the sun around its axis was determined. In 1843, the German astronomer G. Schwabe discovered the cyclicity of solar activity. The development of methods of spectral analysis made it possible to study the physical conditions of the sun. In 1814, J. Fraunhofer discovered dark absorption lines in the spectrum of the sun; this marked the beginning of the study of the chemical composition of the sun. Since 1836, observations of solar eclipses have been regularly carried out, which led to the discovery of the corona and chromosphere of the sun. ., as well as solar prominences. In 1913, the American astronomer J. Hale observed the Zeeman splitting of Fraunhofer lines in the spectrum of sunspots and thereby proved the existence of magnetic fields in the north. By 1942, the Swedish astronomer B. Edlen and others identified several lines in the spectrum of the solar corona with lines of highly ionized elements, thereby proving the high temperature in the solar corona. In 1931, B. Lio invented a solar coronagraph, which made it possible to observe the corona and chromosphere outside of eclipses. In the early 40s. 20th century The radio emission of the Sun was discovered. A significant impetus for the development of solar physics in the 2nd half of the 20th century. contributed to the development of magnetic hydrodynamics and plasma physics. Since the beginning of the space era, the study of ultraviolet and X-ray radiation from the sun has been carried out using methods of extra-atmospheric astronomy using rockets, automatic orbital observatories on Earth satellites, and space laboratories with people on board. In the USSR, S. research is conducted at the Crimean and Pulkovo observatories, and in astronomical institutions in Moscow, Kyiv, Tashkent, and Alma-Ata. Abastumani, Irkutsk, etc. Most foreign astrophysical observatories are engaged in astrophysical research (see Astronomical observatories and institutes).
The rotation of the sun around its axis occurs in the same direction as the rotation of the Earth, in a plane inclined by 7?15" to the plane of the Earth's orbit (ecliptic). The speed of rotation is determined by the apparent movement of various parts in the atmosphere of the sun and by the shift of spectral lines in the spectrum of the edge of the solar disk due to the Doppler effect. Thus, it was discovered that the rotation period of the solar system is different at different latitudes. The position of various parts on the solar surface is determined using heliographic coordinates measured from the solar equator (heliographic latitude) and from the central meridian. the visible disk of S. or from a certain meridian chosen as the initial one (the so-called Carrington meridian). In this case, it is believed that S. rotates as a rigid body. The position of the initial meridian is given in the Astronomical Yearbooks for each day. position of the S axis on the celestial sphere. Points with a heliographic latitude of 17? make one revolution relative to the Earth in 27.275 days (synodic period). The rotation time at the same latitude N relative to the stars (sidereal period) is 25.38 days. The angular velocity of rotation w for sidereal rotation varies with heliographic latitude j according to the law: w = 14?, 44-3? sin2j per day. The linear speed of rotation at the northern equator is about 2000 m/sec.
S. as a star is a typical yellow dwarf and is located in the middle part of the main sequence of stars on the Hertzsprung-Russell diagram. The visible photovisual magnitude of S. is - 26.74, the absolute visual magnitude Mv is + 4.83. The color index C is for the case of blue (B) and visual (V) regions of the spectrum MB - MV = 0.65. Spectral class C. G2V. The speed of movement relative to the set of nearby stars is 19.7? 103 m/sec. S. is located inside one of the spiral branches of our Galaxy at a distance of about 10 kpc from its center. The period of revolution of the sun around the center of the Galaxy is about 200 million years. S.'s age is about 5?109 years.
The internal structure of S. is determined on the assumption that it is a spherically symmetrical body and is in equilibrium. The energy transfer equation, the law of conservation of energy, the equation of state of an ideal gas, the Stefan-Boltzmann law and the conditions of hydrostatic, radiative and convective equilibrium, together with the values of the total luminosity, total mass and radius determined from observations and data on its chemical composition, make it possible to construct a model internal structure of S. It is believed that the hydrogen content in S. by weight is about 70%, helium is about 27%, and the content of all other elements is about 2.5%. Based on these assumptions, it is calculated that the temperature in the center of the North is 10-15?106 K, the density is about 1.5’105 kg/m3, and the pressure is 3.4’1016 n/m2 (about 3’1011 atmospheres). It is believed that the source of energy that replenishes radiation losses and maintains the high temperature of the sun are nuclear reactions occurring in the bowels of the sun. The average amount of energy generated inside the sun is 1.92 erg per g per second. The release of energy is determined by nuclear reactions , in which hydrogen is converted into helium. In the north, 2 groups of thermonuclear reactions of this type are possible: the so-called. proton-proton (hydrogen) cycle and carbon cycle (Bethe cycle). It is most likely that the proton-proton cycle predominates in the North, consisting of three reactions, in the first of which deuterium nuclei (heavy isotope of hydrogen, atomic mass 2) are formed from hydrogen nuclei; in the second of the deuterium nuclei, nuclei of the helium isotope with atomic mass 3 are formed, and, finally, in the third of them, nuclei of the stable helium isotope with atomic mass 4 are formed.
The transfer of energy from the inner layers of solarium occurs mainly through the absorption of electromagnetic radiation coming from below and subsequent re-emission. As a result of a decrease in temperature with distance from the center of the sun, the wavelength of radiation gradually increases, transferring most of the energy to the upper layers (see Wien's law of radiation). The transfer of energy by the movement of hot matter from the inner layers, and cooled matter inward (convection) plays a significant role in comparatively higher layers forming the convective zone of the sun, which begins at a depth of about 0.2 solar radii and has a thickness of about 108 m. The speed of convective movements increases with distance from the center of the sun and in the outer part of the convective zone reaches (2-2. 5)?103 m/sec. In even higher layers (in the solar atmosphere), energy transfer is again carried out by radiation. In the upper layers of the solar atmosphere (in the chromosphere and corona), part of the energy is delivered by mechanical and magnetohydrodynamic waves, which are generated in the convective zone but are absorbed only in these layers. The density in the upper atmosphere is very low, and the necessary removal of energy due to radiation and thermal conduction is only possible if the kinetic temperature of these layers is high enough. Finally, in the upper part of the solar corona, most of the energy is carried away by flows of matter moving from the sun, the so-called. solar wind. the temperature in each layer is set at such a level that an energy balance is automatically achieved: the amount of energy brought in due to the absorption of all types of radiation, thermal conductivity or movement of matter is equal to the sum of all energy losses of the layer.
The total radiation of the sun is determined by the illumination created by it on the surface of the Earth - about 100 thousand lux when the sun is at its zenith. Outside the atmosphere, at the average distance of the Earth from the north, the illumination is 127 thousand lux. The solar luminous intensity is 2.84 x 1027; the amount of light energy arriving per minute per 1 cm3 area, placed perpendicular to the sun's rays outside the atmosphere at the average distance of the Earth from the sun, is called the solar constant. The power of the total radiation of the Sun is 3.83?1026 watts, of which about 2?1017 watts hits the Earth, the average brightness of the Sun's surface (when observed outside the Earth's atmosphere) is 1.98?109 nits, the brightness of the center of the Sun's disk is - 2.48?109 nt. The brightness of the S. disk decreases from the center to the edge, and this decrease depends on the wavelength, so that the brightness at the edge of the S. disk, for example, for light with a wavelength of 3600 A, is about 0.2 of the brightness of its center, and for 5000 A - about 0.3 brightness of the center of the C disk. At the very edge of the C disk, the brightness drops 100 times in less than one arcsecond, so the boundary of the C disk looks very sharp (Fig. 1).
The spectral composition of the light emitted by solar energy, that is, the energy distribution in the solar spectrum (after taking into account the influence of absorption in the earth’s atmosphere and the influence of Fraunhofer lines), in general terms corresponds to the energy distribution in the radiation of an absolutely black body with a temperature of about 6000 K. However, There are noticeable deviations in certain parts of the spectrum. The maximum energy in S.'s spectrum corresponds to a wavelength of 4600 A. S.'s spectrum is a continuous spectrum on which more than 20 thousand absorption lines (Fraunhofer lines) are superimposed. More than 60% of them are identified with spectral lines of known chemical elements by comparing the wavelengths and relative intensity of the absorption line in the solar spectrum with laboratory spectra. The study of Fraunhofer lines provides information not only about the chemical composition of the solar atmosphere, but also about the physical conditions in those layers in which certain absorption lines are formed. The predominant element in S. is hydrogen. The number of helium atoms is 4-5 times less than hydrogen. The number of atoms of all other elements combined is at least 1000 times less than the number of hydrogen atoms. Among them, the most abundant are oxygen, carbon, nitrogen, magnesium, silicon, sulfur, iron, etc. In the spectrum of oxygen, one can also identify lines belonging to certain molecules and free radicals: OH, NH, CH, CO, etc.
Magnetic fields in the sun are measured mainly by the Zeeman splitting of absorption lines in the spectrum of the sun (see Zeeman effect). There are several types of magnetic fields in the north (see Solar magnetism). The total magnetic field of the sun is small and reaches a strength of 1 e of one polarity or another and changes with time. This field is closely related to the interplanetary magnetic field and its sector structure. Magnetic fields associated with solar activity can reach a intensity of several thousand Oe in sunspots. The structure of magnetic fields in active regions is very intricate, magnetic poles of different polarities alternate. There are also local magnetic regions with field strengths of hundreds of Oe outside sunspots. Magnetic fields penetrate both the chromosphere and the solar corona. Magnetogasdynamic and plasma processes play a major role in the north. At a temperature of 5000-10,000 K, the gas is sufficiently ionized, its conductivity is high, and due to the enormous scale of solar phenomena, the significance of electromechanical and magnetomechanical interactions is very large (see Cosmic magnetohydrodynamics).
The atmosphere of the sun is formed by external, observable layers. Almost all of solar radiation comes from the lower part of its atmosphere, called the photosphere. Based on the equations of radiative energy transfer, radiative and local thermodynamic equilibrium and the observed radiation flux, it is possible to theoretically construct a model of the distribution of temperature and density with depth in the photosphere. The thickness of the photosphere is about 300 km, its average density is 3? 10 = 4 kg/m3. the temperature in the photosphere drops as we move to more outer layers, its average value is about 6000 K, at the boundary of the photosphere it is about 4200 K. The pressure varies from 2? 104 to 102 n/m2. The existence of convection in the subphotospheric zone of the sun is manifested in the uneven brightness of the photosphere and its visible granularity - the so-called. granulation structure. The granules are bright spots of a more or less round shape, visible in the image of S. obtained in white light (Fig. 2). The size of the granules is 150-1000 km, the lifetime is 5-10 minutes. individual granules can be observed within 20 minutes. Sometimes granules form clusters up to 30,000 km in size. Granules are brighter than intergranular spaces by 20-30%, which corresponds to a difference in temperature of an average of 300 K. Unlike other formations, on the surface of the sun granulation is the same at all heliographic latitudes and not depends on solar activity. The speeds of chaotic movements (turbulent speeds) in the photosphere are, according to various definitions, 1-3 km/sec. Quasiperiodic oscillatory motions in the radial direction have been detected in the photosphere. They occur on areas measuring 2-3 thousand km, with a period of about 5 minutes and a velocity amplitude of about 500 m/sec. After several periods, the oscillations in a given location die out, then they can arise again. Observations also showed the existence of cells in which movement occurs in the horizontal direction from the center of the cell to its borders. The speed of such movements is about 500 m/sec. The cell sizes of supergranules are 30-40 thousand km. The position of the supergranules coincides with the cells of the chromospheric network. At the boundaries of supergranules, the magnetic field is enhanced. It is assumed that supergranules reflect the existence of convective cells of the same size at a depth of several thousand km below the surface. It was initially assumed that the photosphere produces only continuous radiation, and absorption lines are formed in the reversal layer located above it. Later it was found that both spectral lines and a continuous spectrum are formed in the photosphere. However, to simplify mathematical calculations when calculating spectral lines, the concept of an inverting layer is sometimes used.
Sun spots and flares. Sunspots and faculae are often observed in the photosphere (Fig. 1 and 2). Sunspots are dark formations, usually consisting of a darker core (umbra) and the surrounding penumbra. The diameters of the spots reach 200,000 km. Sometimes the spot is surrounded by a light border. Very small spots are called pores. The lifetime of spots is from several hours to several months. The spectrum of spots contains even more lines and absorption bands than in the spectrum of the photosphere; it resembles the spectrum of a star of spectral class KO. Shifts of lines in the spectrum of spots due to the Doppler effect indicate the movement of matter in the spots - outflow at lower levels and inflow at higher levels, movement speeds reach 3? 103 m/sec (Evershed effect). From comparisons of line intensities and the continuous spectrum of spots and the photosphere, it follows that spots are 1-2 thousand degrees cooler than the photosphere (4500 K and below). As a result, against the background of the photosphere, the spots appear dark, the brightness of the core is 0.2-0.5 the brightness of the photosphere, and the brightness of the penumbra is about 80% of the photospheric brightness. All sunspots have a strong magnetic field, reaching a strength of 5000 Oe for large sunspots. Typically, sunspots form groups that, according to their magnetic field, can be unipolar, bipolar and multipolar, i.e. containing many spots of different polarity, often united by a common penumbra. Groups of sunspots are always surrounded by faculae and flocculi, prominences, solar flares sometimes occur near them, and in the solar corona above them formations in the form of rays of helmets and fans are observed - all this together forms an active region in the north. The average annual number of observed spots and active regions, and Also, the average area occupied by them changes with a period of about 11 years. This is an average value, but the duration of individual cycles of solar activity ranges from 7.5 to 16 years (see Solar activity). The largest number of spots simultaneously visible on the surface of the sun changes more than twice for different cycles. Mostly spots are found in the so-called. royal zones extending from 5 to 30? heliographic latitude on both sides of the solar equator. At the beginning of the solar activity cycle, the latitude of the sunspot location is higher, at the end of the cycle it is lower, and at higher latitudes the spots of the new cycle appear. More often, bipolar groups of sunspots are observed, consisting of two large sunspots - the head and the subsequent ones, having the opposite magnetic polarity, and several smaller ones. The head spots have the same polarity throughout the entire cycle of solar activity; these polarities are opposite in the northern and southern hemispheres of the C. Apparently, the spots are depressions in the photosphere, and the density of matter in them is less than the density of matter in the photosphere at the same level .
In active regions of the sun, faculae are observed - bright photospheric formations, visible in white light mainly near the edge of the solar disk. Typically, faculae appear before sunspots and exist for some time after their disappearance. The area of flare areas is several times larger than the area of the corresponding group of spots. The number of torches on the solar disk depends on the phase of the solar activity cycle. The faculae have the maximum contrast (18%) near the edge of the S. disk, but not at the very edge. In the center of the S. disk, the torches are practically invisible, their contrast is very low. the torches have a complex fibrous structure, their contrast depends on the wavelength at which observations are made. the temperature of the torches is several hundred degrees higher than the temperature of the photosphere, the total radiation from 1 cm2 exceeds the photospheric one by 3-5%. Apparently, the torches rise somewhat above the photosphere. The average duration of their existence is 15 days, but can reach almost 3 months.
Chromosphere. Above the photosphere there is a layer of the sun's atmosphere called the chromosphere. Without special telescopes with narrow-band light filters, the chromosphere is visible only during total solar eclipses as a pink ring surrounding a dark disk, in those minutes when the Moon completely covers the photosphere. Then one can observe the spectrum of the chromosphere, the so-called. flare spectrum. At the edge of the S. disk, the chromosphere appears to the observer as an uneven strip from which individual teeth protrude - chromospheric spicules. The diameter of the spicules is 200-2000 km, the height is about 10,000 km, the speed of plasma rise in the spicules is up to 30 km/sec. At the same time, up to 250 thousand spicules exist in the north. When observed in monochromatic light (for example, in the light of the ionized calcium line 3934 A), a bright chromospheric network is visible on the C disk, consisting of individual nodules - small ones with a diameter of 1000 km and large ones with a diameter of 2000 to 8000 km. Large nodules are clusters of small ones. The size of the grid cells is 30-40 thousand km. It is believed that spicules are formed at the boundaries of the cells of the chromospheric grid. When observed in the light of the red hydrogen line 6563 A, a characteristic vortex structure is visible near sunspots in the chromosphere (Fig. 3). The density in the chromosphere decreases with increasing distance from the center C. The number of atoms per 1 cm3 varies from 1015 near the photosphere to 109 in the upper part of the chromosphere. The spectrum of the chromosphere consists of hundreds of emission spectral lines of hydrogen, helium, and metals. The strongest of them are the red line of hydrogen Na (6563 A) and the H and K lines of ionized calcium with wavelengths of 3968 A and 3934 A. The extent of the chromosphere is not the same when observed in different spectrum lines: in the strongest chromospheric lines it can be traced to 14 000 km above the photosphere. A study of the spectra of the chromosphere led to the conclusion that in the layer where the transition from the photosphere to the chromosphere occurs, the temperature passes through a minimum and, as the height above the base of the chromosphere increases, it becomes equal to 8-10 thousand K, and at an altitude of several thousand km reaches 15 -20 thousand K. It has been established that in the chromosphere there is a chaotic (turbulent) movement of gas masses with velocities up to 15?103 m/sec. In the chromosphere, torches in active regions are visible in the monochromatic light of strong chromospheric lines as light formations, usually called flocculi . Dark formations called filaments are clearly visible in the Ha line. At the edge of the S. disk, the filaments protrude beyond the disk and are observed against the sky as bright prominences. Most often, filaments and prominences are found in four zones located symmetrically relative to the solar equator: polar zones north of + 40? and to the south -40? heliographic latitude and low latitude zones around? 30? at the beginning of the solar activity cycle and 17? at the end of the cycle. Filaments and prominences of low-latitude zones show a well-defined 11-year cycle, their maximum coincides with the maximum of the sunspots. In high-latitude prominences, the dependence on the phases of the solar activity cycle is less pronounced; the maximum occurs 2 years after the maximum of the spots. The filaments, which are quiet prominences, can reach the length of the solar radius and exist for several revolutions of the north. The average height of prominences above the surface of the sun is 30-50 thousand km, the average length is 200 thousand km, and the width is 5 thousand km. According to the research of A. B. Severny, all prominences can be divided into 3 groups according to the nature of their movements: electromagnetic, in which movements occur along ordered curved trajectories - magnetic field lines; chaotic, in which disordered, turbulent movements predominate (velocities of the order of 10 km/sec); eruptive, in which the substance of an initially quiet prominence with chaotic movements is suddenly ejected with increasing speed (reaching 700 km/sec) away from the north. The temperature in the prominences (filaments) is 5-10 thousand K, the density is close to the average density of the chromosphere. The filaments, which are active, rapidly changing prominences, usually change greatly within a few hours or even minutes. The shape and nature of movements in prominences are closely related to the magnetic field in the chromosphere and solar corona.
The solar corona is the outermost and most tenuous part of the solar atmosphere, extending over several (more than 10) solar radii. Until 1931, the corona could only be observed during total solar eclipses in the form of a silvery-pearly glow around the S. disk covered by the Moon (see vol. 9, insert to pp. 384-385). The details of its structure clearly stand out in the crown: helmets, fans, coronal rays and polar brushes. After the invention of the coronagraph, the solar corona began to be observed outside of eclipses. The overall shape of the corona changes with the phase of the solar activity cycle: in years of minimum the corona is strongly elongated along the equator, in years of maximum it is almost spherical. In white light, the surface brightness of the solar corona is a million times less than the brightness of the center of disk C. Its glow is formed mainly as a result of scattering of photospheric radiation by free electrons. Almost all atoms in the corona are ionized. The concentration of ions and free electrons at the base of the corona is 109 particles per 1 cm3. The corona is heated similarly to the chromosphere. The greatest energy release occurs in the lower part of the corona, but due to the high thermal conductivity, the corona is almost isothermal - the temperature drops outward very slowly. The outflow of energy in the corona occurs in several ways. In the lower part of the corona, the main role is played by downward energy transfer due to thermal conductivity. The loss of energy is caused by the departure of the fastest particles from the corona. In the outer parts of the corona, most of the energy is carried away by the solar wind - a flow of coronal gas, the speed of which increases with distance from the north, from several km/sec at its surface to 450 km/sec at a distance from the Earth. the temperature in the corona exceeds 106K. In active regions the temperature is higher - up to 107K. Above active areas, so-called coronal condensations, in which the concentration of particles increases tens of times. Part of the radiation from the inner corona is the emission lines of multiply ionized atoms of iron, calcium, magnesium, carbon, oxygen, sulfur and other chemical elements. They are observed both in the visible part of the spectrum and in the ultraviolet region. The solar corona generates solar radiation in the meter range and X-ray radiation, which is amplified many times in active regions. As calculations have shown, the solar corona is not in equilibrium with the interplanetary medium. Streams of particles propagate from the corona into interplanetary space, forming the solar wind. Between the chromosphere and the corona there is a relatively thin transition layer, in which a sharp increase in temperature occurs to values characteristic of the corona. The conditions in it are determined by the flow of energy from the corona as a result of thermal conductivity. The transition layer is the source of most of the ultraviolet radiation from the sun. The chromosphere, transition layer and corona produce all the observed radio emission from the sun. In active regions, the structure of the chromosphere, corona and transition layer changes. This change, however, has not yet been sufficiently studied.
Solar flares. In active regions of the chromosphere, sudden and relatively short-term increases in brightness are observed, visible in many spectral lines at once. These bright formations last from several minutes to several hours. They are called solar flares (formerly called chromospheric flares). The flares are best seen in the light of the hydrogen Ha line, but the brightest are sometimes visible in white light. In the spectrum of a solar flare there are several hundred emission lines of various elements, neutral and ionized. the temperature of those layers of the solar atmosphere that produce glow in the chromospheric lines (1-2) is ? 104 K, in higher layers - up to 107 K. The density of particles in a flare reaches 1013-1014 per 1 cm3. The area of solar flares can reach 1015 m3. Typically, solar flares occur near rapidly developing groups of sunspots with a magnetic field of complex configuration. They are accompanied by activation of fibers and flocculi, as well as emissions of substances. During a flare, a large amount of energy is released (up to 1010-1011 J). It is assumed that the energy of a solar flare is initially stored in the magnetic field and then quickly released, which leads to local heating and acceleration of protons and electrons, causing further heating of the gas, its glow in different parts of the spectrum of electromagnetic radiation, the formation of a shock wave. Solar flares produce a significant increase in solar ultraviolet radiation and are accompanied by bursts of X-ray radiation (sometimes very powerful), bursts of radio emission, and the release of high-energy corpuscles up to 1010 eV. Sometimes bursts of X-ray radiation are observed without increasing the glow in the chromosphere. Some solar flares (they are called proton flares) are accompanied by particularly strong streams of energetic particles - cosmic rays of solar origin. Proton flares create a danger for astronauts in flight, because energetic particles, colliding with atoms of the shell of a spacecraft, generate bremsstrahlung, X-ray and gamma radiation, sometimes in dangerous doses.
The influence of solar activity on terrestrial phenomena. Energy is ultimately the source of all types of energy used by humanity (except atomic energy). This is the energy of the wind, falling water, the energy released during the combustion of all types of fuel. The influence of solar activity on the processes occurring in the atmosphere, magnetosphere and biosphere of the Earth is very diverse (see Solar-terrestrial connections).
Instruments for studying S. Observations of S. are carried out using small or medium-sized refractors and large reflecting telescopes, in which most of the optics are stationary, and the sun's rays are directed inside the horizontal or tower installation of the telescope using one (siderostat, heliostat) or two (celostat ) moving mirrors (see figure for article Tower telescope). When constructing large solar telescopes, special attention is paid to high spatial resolution along the C disk. A special type of solar telescope has been created - an out-of-eclipse coronagraph. Inside the coronagraph, the image of the sun is eclipsed by an artificial “Moon” - a special opaque disk. In the coronagraph, the amount of scattered light is reduced many times, so it is possible to observe the outermost layers of the atmosphere outside the eclipse. Solar telescopes are often equipped with narrow-band light filters, allowing observations in the light of one spectral line. Neutral density filters with variable radial transparency have also been created, making it possible to observe the solar corona at a distance of several radii C. Large solar telescopes are usually equipped with powerful spectrographs with photographic or photoelectric recording of spectra. The spectrograph may also have a magnetograph - a device for studying Zeeman splitting and polarization of spectral lines and determining the magnitude and direction of the magnetic field in the north. The need to eliminate the washing out effect of the earth's atmosphere, as well as the study of solar radiation in the ultraviolet, infrared and some other regions of the spectrum, which absorbed in the Earth's atmosphere led to the creation of orbital observatories outside the atmosphere, making it possible to obtain spectra of the sun and individual formations on its surface outside the Earth's atmosphere.
- We can install a series of large reflectors at the L1 Lagrange point to block some of the light from reaching the Earth.
- We can geoengineer our planet's atmosphere/albedo to reflect more light and absorb less.
- We can rid the planet of the greenhouse effect by removing methane and carbon dioxide molecules from the atmosphere.
- We can leave Earth and focus on terraforming outer worlds like Mars.
In theory, everything can work, but it will require enormous effort and support.
However, the decision to migrate the Earth to a distant orbit may become final. And although we will have to constantly move the planet out of orbit to maintain a constant temperature, this will take hundreds of millions of years. To compensate for the effect of a 1% increase in the Sun's luminosity, the Earth must be moved 0.5% away from the Sun; to compensate for an increase of 20% (that is, over 2 billion years), the Earth needs to be moved 9.5% further away. The Earth will no longer be 149,600,000 km from the Sun, but 164,000,000 km.
The distance from the Earth to the Sun has not changed much over the past 4.5 billion years. But if the Sun heats up and we don't want the Earth to completely fry, we'll have to seriously consider planetary migration.
This requires a lot of energy! Moving the Earth - all six septillion kilograms (6 x 10 24) of it - away from the Sun would significantly change our orbital parameters. If we move the planet 164,000,000 km away from the Sun, there are obvious differences:
- The Earth will take 14.6% longer to orbit the Sun
- to maintain a stable orbit, our orbital speed must drop from 30 km/s to 28.5 km/s
- if the Earth's rotation period remains the same (24 hours), the year will have 418 days instead of 365
- The Sun will be much smaller in the sky - by 10% - and the tides caused by the Sun will be weaker by several centimeters
If the Sun swells in size and the Earth moves away from it, the two effects do not quite cancel out; The sun will appear smaller from Earth
But in order to take the Earth that far, we need to make very large energetic changes: we will need to change the gravitational potential energy of the Sun-Earth system. Even taking into account all other factors, including the slowing of the Earth's motion around the Sun, we would have to change the Earth's orbital energy by 4.7 x 10 35 joules, which is equivalent to 1.3 x 10 20 terawatt hours: 10 15 times the annual energy cost that humanity bears. You would think that in two billion years they would be different, and they are, but not much. We will need 500,000 times more energy than humanity generates globally today, all of which will go into moving the Earth to safety.
The speed at which planets orbit the Sun depends on their distance from the Sun. Earth's slow migration of 9.5% distance will not disrupt the orbits of other planets.
Technology is not the most difficult issue. The difficult question is much more fundamental: how do we get all this energy? In reality, there is only one place that will satisfy our needs: the Sun itself. Currently, the Earth receives about 1,500 watts of energy per square meter from the Sun. To get enough power to migrate the Earth in the required amount of time, we would have to build an array (in space) that would collect 4.7 x 10 35 joules of energy, uniformly, over 2 billion years. This means we need an array with an area of 5 x 10 15 square meters (and 100% efficiency), which is equivalent to the entire area of ten planets like ours.
The concept of space solar power has been in development for a long time, but no one has yet imagined an array of solar cells measuring 5 billion square kilometers.
Therefore, to transport the Earth to a safe orbit further away, you will need a solar panel of 5 billion square kilometers of 100% efficiency, all of the energy of which will be spent on pushing the Earth into another orbit within 2 billion years. Is this physically possible? Absolutely. With modern technology? Not at all. Is this practically possible? With what we know now, almost certainly not. Dragging an entire planet is difficult for two reasons: first, because of the gravitational pull of the Sun and because of the massiveness of the Earth. But we have just such a Sun and such an Earth, and the Sun will heat up regardless of our actions. Until we figure out how to collect and use this amount of energy, we will need other strategies.
There are 3 options for deorbiting - move to a new orbit (which in turn may be closer or further from the sun, or even be very elongated), fall into the Sun and leave the solar system. Let's consider only the third option, which, in my opinion, is the most interesting.
As we move further away from the sun, there will be less ultraviolet light available for photosynthesis and the average temperature on the planet will decrease year after year. Plants will be the first to suffer, leading to major disruptions in food chains and ecosystems. And the ice age will come quite quickly. The only oases with more or less conditions will be near geothermal springs and geysers. But not for long.
After a certain number of years (by the way, there will be no more seasons), at a certain distance from the sun, unusual rains will begin on the surface of our planet. It will be rains of oxygen. If you're lucky, maybe it will snow from the oxygen. I cannot say for sure whether people on the surface will be able to adapt to this - there will be no food either, steel in such conditions will be too fragile, so it is unclear how to obtain fuel. the surface of the ocean will freeze to a considerable depth, the ice cap due to the expansion of ice will cover the entire surface of the planet except the mountains - our planet will become white.
But the temperature of the planet’s core and mantle will not change, so under the ice cap at a depth of several kilometers the temperature will remain quite tolerable. (if you dig such a mine and provide it with constant food and oxygen, you can even live there)
The funniest thing is in the depths of the sea. Where even now a ray of light does not penetrate. There, at a depth of several kilometers below the surface of the ocean, there are entire ecosystems that absolutely do not depend on the sun, on photosynthesis, on solar heat. It has its own cycles of substances, chemosynthesis instead of photosynthesis, and the required temperature is maintained due to the heat of our planet (volcanic activity, underwater hot springs, and so on). Since the temperature inside our planet is ensured by its gravity, mass, even without the sun, it is also outside the solar systems, stable conditions and the required temperature will be maintained there. And the life that boils in the depths of the sea, at the bottom of the ocean, will not even notice that the sun has disappeared. That life will not even know that our planet once revolved around the sun. Perhaps it will evolve.
It is also unlikely, but also possible, that a snow ball - the Earth - will someday, billions of years later, fly to one of the stars of our galaxy and fall into its orbit. It is also possible that in that orbit of another star our planet will “thaw” and conditions favorable for life will appear on the surface. Perhaps life in the depths of the sea, having overcome this entire path, will again come to the surface, as it already happened once. Perhaps, as a result of evolution, intelligent life will appear on our planet after this. And finally, maybe they will find surviving media with questions and answers from the site in the remains of one of the data centers
It’s impossible to explain… September 29th, 2016
Scientists from NASA's Jet Propulsion Laboratory and Los Alamos National Laboratory (USA) have compiled a list of astronomical phenomena observed in the solar system that are completely impossible to explain...
These facts have been verified many times, and there is no doubt about their reality. But they don’t fit into the existing picture of the world at all. And this means that either we do not quite correctly understand the laws of nature, or... someone is constantly changing these very laws.
Here are some examples:
Who accelerates space probes
In 1989, the Galileo research apparatus set off on a long journey to Jupiter. In order to give it the required speed, scientists used a “gravitational maneuver”. The probe approached the Earth twice so that the planet's gravitational force could “push” it, giving additional acceleration. But after the maneuvers, the speed of the Galileo turned out to be higher than calculated.
The technique was worked out, and previously all devices overclocked normally. Then scientists had to send three more research stations into deep space. The NEAR probe went to the Eros asteroid, Rosetta flew to study the comet Churyumov-Gerasimenko, and Cassini went to Saturn. All of them performed the gravitational maneuver in the same way, and for all of them the final speed turned out to be greater than the calculated one - scientists monitored this indicator seriously after the noticed anomaly with Galileo.
There was no explanation for what was happening. But for some reason, all the devices sent to other planets after Cassini did not receive a strange additional acceleration during the gravitational maneuver. So what was that “something” in the period from 1989 (Galileo) to 1997 (Cassini) that gave all the probes going into deep space additional acceleration?
Scientists are still shrugging their shoulders: who needed to “push” four satellites? In ufological circles, there was even a version that some Higher Intelligence decided that it would be necessary to help earthlings explore the Solar System.
Now this effect is not observed, and whether it will ever appear again is unknown.
Why does the Earth run away from the sun?
Scientists have long learned to measure the distance from our planet to the star. Now it is considered equal to 149,597,870 kilometers. Previously, it was believed that it was unchangeable. But in 2004, Russian astronomers discovered that the Earth is moving away from the Sun by about 15 centimeters per year - 100 times more than the measurement error.
Something that was previously described only in science fiction novels is happening: the planet has gone on a “free float”? The nature of the journey that has begun is still unknown. Of course, if the rate of removal does not change, it will be hundreds of millions of years before we move away from the Sun enough for the planet to freeze. But suddenly the speed will increase. Or, on the contrary, will the Earth begin to approach the star?
So far no one knows what will happen next.
Who doesn’t allow “pioneers” to go abroad?
The American probes Pioneer 10 and Pioneer 11 were launched in 1972 and 1983, respectively. By now they should have already flown out of the solar system. However, at a certain moment, both one and the other, for unknown reasons, began to change their trajectory, as if an unknown force did not want to let them go too far.
Pioneer 10 has already deviated by four hundred thousand kilometers from the calculated trajectory. Pioneer 11 exactly follows the path of its brother. There are many versions: the influence of solar wind, fuel leaks, programming errors. But all of them are not very convincing, since both ships, launched 11 years apart, behave the same.
If we do not take into account the machinations of aliens or the divine plan not to release people beyond the solar system, then perhaps the influence of the mysterious dark matter is manifested here. Or are there some gravitational effects unknown to us?
What lurks on the outskirts of our system
Far, far beyond the dwarf planet Pluto there is a mysterious asteroid Sedna - one of the largest in our system. In addition, Sedna is considered the reddest object in our system - it is even redder than Mars. Why is unknown.
But the main mystery is different. It takes 10 thousand years to complete a revolution around the Sun. Moreover, it orbits in a very elongated orbit. Either this asteroid flew to us from another star system, or perhaps, as some astronomers believe, it was knocked out of its circular orbit by the gravitational pull of some large object. Which one? Astronomers can't detect it.
Why are solar eclipses so perfect?
In our system, the sizes of the Sun and Moon, as well as the distance from the Earth to the Moon and to the Sun, are selected in a very original way. If you observe a solar eclipse from our planet (by the way, the only one where there is intelligent life), then Selene’s disk perfectly evenly covers the disk of the luminary - their sizes coincide exactly.
If the Moon were a little smaller or further from the Earth, we would never have had total solar eclipses. Accident? I can’t believe it...
Why do we live so close to our luminary?
In all star systems studied by astronomers, the planets are ranked according to the same ranking: the larger the planet, the closer it is to the star. In our solar system, the giants - Saturn and Jupiter - are located in the middle, letting the “little ones” ahead - Mercury, Venus, Earth and Mars. Why this happened is unknown.
If we had the same world order as in the vicinity of all other stars, then the Earth would be located somewhere in the area of current Saturn. And there reigns hellish cold and no conditions for intelligent life.
Radio signal from the constellation Sagittarius
In the 1970s, the United States began a program to search for possible alien radio signals. To do this, the radio telescope was directed to different parts of the sky, and it scanned the airwaves at different frequencies, trying to detect a signal of artificial origin.
For several years, astronomers could not boast of any results. But on August 15, 1977, while astronomer Jerry Ehman was on duty, the recorder that recorded everything that fell into the “ears” of the radio telescope recorded a signal or noise that lasted 37 seconds. This phenomenon is called Wоw! - according to the note in the margins, which the stunned Ehman wrote in red ink.
The “signal” was at a frequency of 1420 MHz. According to international agreements, no earthly transmitter operates in this range. It came from the direction of the constellation Sagittarius, where the nearest star is located 220 light years from Earth. Whether it was artificial - there is still no answer. Subsequently, scientists repeatedly searched this area of the sky. But to no avail.
Dark matter
All galaxies in our Universe revolve around one center at high speed. But when scientists calculated the total masses of galaxies, it turned out that they were too light. And according to the laws of physics, this whole carousel would have broken down long ago. However, it doesn't break.
To explain what is happening, scientists came up with a hypothesis that there is some dark matter in the Universe that cannot be seen. But astronomers have no idea yet what it is and how to feel it. It is only known that its mass is 90% of the mass of the Universe. This means that we know what kind of world surrounds us, just one tenth.
Life on Mars
The search for organic matter on the Red Planet began in 1976 - American Viking spacecraft landed there. They had to conduct a series of experiments in order to either confirm or refute the hypothesis about the habitability of the planet. The results turned out to be contradictory: on the one hand, methane was detected in the atmosphere of Mars - obviously of biogenic origin, but not a single organic molecule was identified.
The strange results of the experiments were attributed to the chemical composition of the Martian soil and it was decided that there was no life on the Red Planet after all. However, a number of other studies suggest that there was once moisture on the surface of Mars, which again speaks in favor of the existence of life. According to some, we may be talking about underground life forms.
What riddles are not worth a damn?
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