Jupiter is the fifth planet from the Sun and the largest in the solar system. Along with Saturn, Uranus and Neptune, Jupiter is classified as a gas giant.
The planet has been known to people since ancient times, which is reflected in the mythology and religious beliefs of various cultures: Mesopotamian, Babylonian, Greek and others. The modern name of Jupiter comes from the name of the ancient Roman supreme god of thunder.
A number of atmospheric phenomena on Jupiter - such as storms, lightning, auroras - have scales that are orders of magnitude greater than those on Earth. A notable formation in the atmosphere is the Great Red Spot - a giant storm known since the 17th century.
Jupiter has at least 67 moons, the largest of which - Io, Europa, Ganymede and Callisto - were discovered by Galileo Galilei in 1610.
Jupiter is being studied with the help of ground-based and orbiting telescopes; Since the 1970s, 8 NASA interplanetary vehicles have been sent to the planet: Pioneers, Voyagers, Galileo and others.
During the great oppositions (one of which took place in September 2010), Jupiter is visible to the naked eye as one of the brightest objects in the night sky after the Moon and Venus. Jupiter's disk and moons are popular objects of observation for amateur astronomers who have made a number of discoveries (for example, the Shoemaker-Levy comet that collided with Jupiter in 1994, or the disappearance of Jupiter's southern equatorial belt in 2010).
Optical range
In the infrared region of the spectrum lie the lines of the H2 and He molecules, as well as the lines of many other elements. The number of the first two carries information about the origin of the planet, and the quantitative and qualitative composition of the rest - about its internal evolution.
However, hydrogen and helium molecules do not have a dipole moment, which means that the absorption lines of these elements are invisible until absorption due to impact ionization begins to dominate. This is on the one hand, on the other - these lines are formed in the uppermost layers of the atmosphere and do not carry information about the deeper layers. Therefore, the most reliable data on the abundance of helium and hydrogen on Jupiter were obtained from the Galileo lander.
As for the rest of the elements, there are also difficulties in their analysis and interpretation. So far, it is impossible to say with complete certainty what processes occur in the atmosphere of Jupiter and how much they affect the chemical composition - both in the inner regions and in the outer layers. This creates certain difficulties in a more detailed interpretation of the spectrum. However, it is believed that all processes capable of influencing the abundance of elements in one way or another are local and highly limited, so that they are not capable of globally changing the distribution of matter.
Jupiter also radiates (mainly in the infrared region of the spectrum) 60% more energy than it receives from the Sun. Due to the processes leading to the production of this energy, Jupiter decreases by about 2 cm per year.
Gamma range
The radiation of Jupiter in the gamma range is associated with the aurora, as well as with the radiation of the disk. First recorded in 1979 by the Einstein Space Laboratory.
On Earth, the aurora regions in the X-ray and ultraviolet practically coincide, however, on Jupiter this is not the case. The region of X-ray auroras is located much closer to the pole than ultraviolet. Early observations revealed a pulsation of radiation with a period of 40 minutes, however, in later observations, this dependence is much worse.
It was expected that the X-ray spectrum of auroral auroras on Jupiter is similar to the X-ray spectrum of comets, however, as observations on Chandra showed, this is not the case. The spectrum consists of emission lines peaking at oxygen lines near 650 eV, at OVIII lines at 653 eV and 774 eV, and at OVII at 561 eV and 666 eV. There are also emission lines at lower energies in the spectral region from 250 to 350 eV, possibly from sulfur or carbon.
Non-auroral gamma radiation was first detected in ROSAT observations in 1997. The spectrum is similar to the spectrum of auroras, however, in the region of 0.7-0.8 keV. The features of the spectrum are well described by the model of coronal plasma with a temperature of 0.4-0.5 keV with solar metallicity, with the addition of Mg10+ and Si12+ emission lines. The existence of the latter is possibly associated with solar activity in October-November 2003.
Observations by the XMM-Newton space observatory have shown that the disk radiation in the gamma spectrum is reflected solar X-ray radiation. In contrast to auroras, no periodicity in the change in the emission intensity on scales from 10 to 100 min was found.
radio surveillance
Jupiter is the most powerful (after the Sun) radio source in the solar system in the decimeter - meter wavelength ranges. The radio emission is sporadic and reaches 10-6 at the burst maximum.
Bursts occur in the frequency range from 5 to 43 MHz (most often around 18 MHz), with an average width of about 1 MHz. The duration of the burst is short: from 0.1-1 s (sometimes up to 15 s). The radiation is strongly polarized, especially in a circle, the degree of polarization reaches 100%. There is a modulation of radiation by Jupiter's close satellite Io, which rotates inside the magnetosphere: the burst is more likely to appear when Io is near elongation with respect to Jupiter. The monochromatic nature of the radiation indicates a selected frequency, most likely a gyrofrequency. The high brightness temperature (sometimes reaching 1015 K) requires the involvement of collective effects (such as masers).
Jupiter's radio emission in the millimeter-short-centimeter ranges is purely thermal in nature, although the brightness temperature is slightly higher than the equilibrium temperature, which suggests a heat flux from the depths. Starting from waves ~9 cm, Tb (brightness temperature) increases - a nonthermal component appears, associated with synchrotron radiation of relativistic particles with an average energy of ~30 MeV in Jupiter's magnetic field; at a wavelength of 70 cm, Tb reaches a value of ~5·104 K. The radiation source is located on both sides of the planet in the form of two extended blades, which indicates the magnetospheric origin of the radiation.
Jupiter among the planets of the solar system
The mass of Jupiter is 2.47 times the mass of the rest of the planets in the solar system.
Jupiter is the largest planet in the solar system, a gas giant. Its equatorial radius is 71.4 thousand km, which is 11.2 times the radius of the Earth.
Jupiter is the only planet whose center of mass with the Sun is outside the Sun and is about 7% of the solar radius away from it.
The mass of Jupiter is 2.47 times the total mass of all the other planets of the solar system combined, 317.8 times the mass of the Earth and about 1000 times less than the mass of the Sun. The density (1326 kg/m2) is approximately equal to the density of the Sun and is 4.16 times less than the density of the Earth (5515 kg/m2). At the same time, the force of gravity on its surface, which is usually taken as the upper layer of clouds, is more than 2.4 times greater than that of the earth: a body that has a mass, for example, 100 kg, will weigh the same as a body weighing 240 kg weighs on the surface Earth. This corresponds to a gravitational acceleration of 24.79 m/s2 on Jupiter versus 9.80 m/s2 for Earth.
Jupiter as a "failed star"
Comparative sizes of Jupiter and Earth.
Theoretical models show that if the mass of Jupiter were much larger than its actual mass, then this would lead to the compression of the planet. Small changes in mass would not entail any significant changes in radius. However, if the mass of Jupiter exceeded its real mass by four times, the density of the planet would increase to such an extent that, under the influence of increased gravity, the size of the planet would greatly decrease. Thus, apparently, Jupiter has the maximum diameter that a planet with a similar structure and history could have. With a further increase in mass, the contraction would continue until, in the process of star formation, Jupiter would become a brown dwarf with a mass exceeding its current one by about 50 times. This gives astronomers reason to consider Jupiter a "failed star," though it's not clear if the formation processes of planets like Jupiter are similar to those that lead to the formation of binary star systems. Although Jupiter would need to be 75 times as massive to become a star, the smallest known red dwarf is only 30% larger in diameter.
Orbit and rotation
When observed from Earth during opposition, Jupiter can reach an apparent magnitude of -2.94m, making it the third brightest object in the night sky after the Moon and Venus. At the greatest distance, the apparent magnitude drops to? 1.61m. The distance between Jupiter and the Earth varies from 588 to 967 million km.
Jupiter's oppositions occur every 13 months. In 2010, the confrontation of the giant planet fell on September 21. Once every 12 years, the great opposition of Jupiter occurs when the planet is near the perihelion of its orbit. During this period of time, its angular size for an observer from the Earth reaches 50 arc seconds, and its brightness is brighter than -2.9m.
The average distance between Jupiter and the Sun is 778.57 million km (5.2 AU), and the period of revolution is 11.86 years. Since the eccentricity of Jupiter's orbit is 0.0488, the difference between the distance to the Sun at perihelion and aphelion is 76 million km.
Saturn makes the main contribution to the perturbations of Jupiter's motion. The first kind of perturbation is secular, acting on a scale of ~70 thousand years, changing the eccentricity of Jupiter's orbit from 0.2 to 0.06, and the inclination of the orbit from ~1° - 2°. The perturbation of the second kind is resonant with a ratio close to 2:5 (with an accuracy of 5 decimal places - 2:4.96666).
The equatorial plane of the planet is close to the plane of its orbit (the inclination of the axis of rotation is 3.13° versus 23.45° for the Earth), so there is no change of seasons on Jupiter.
Jupiter rotates on its axis faster than any other planet in the solar system. The period of rotation at the equator is 9 hours 50 minutes. 30 sec., and at middle latitudes - 9 h. 55 min. 40 sec. Due to the rapid rotation, the equatorial radius of Jupiter (71492 km) is greater than the polar one (66854 km) by 6.49%; thus, the compression of the planet is (1:51.4).
Hypotheses about the existence of life in the atmosphere of Jupiter
At present, the existence of life on Jupiter seems unlikely: the low concentration of water in the atmosphere, the absence of a solid surface, etc. However, back in the 1970s, the American astronomer Carl Sagan spoke about the possibility of the existence of ammonia-based life in the upper atmosphere of Jupiter. It should be noted that even at a shallow depth in the Jovian atmosphere, the temperature and density are quite high, and the possibility of at least chemical evolution cannot be ruled out, since the rate and probability of chemical reactions favor this. However, the existence of water-hydrocarbon life on Jupiter is also possible: in the atmospheric layer containing clouds of water vapor, temperature and pressure are also very favorable. Carl Sagan, together with E. E. Salpeter, having made calculations within the framework of the laws of chemistry and physics, described three imaginary life forms that can exist in the atmosphere of Jupiter:
Chemical composition
The chemical composition of Jupiter's inner layers cannot be determined by modern observational methods, but the abundance of elements in the outer layers of the atmosphere is known with relatively high accuracy, since the outer layers were directly studied by the Galileo lander, which was lowered into the atmosphere on December 7, 1995. The two main components of Jupiter's atmosphere are molecular hydrogen and helium. The atmosphere also contains many simple compounds such as water, methane (CH4), hydrogen sulfide (H2S), ammonia (NH3) and phosphine (PH3). Their abundance in the deep (below 10 bar) troposphere implies that Jupiter's atmosphere is rich in carbon, nitrogen, sulfur, and possibly oxygen, by a factor of 2-4 relative to the Sun.
Other chemical compounds, arsine (AsH3) and german (GeH4), are present but in minor amounts.
The concentration of inert gases, argon, krypton and xenon, exceeds their amount on the Sun (see table), while the concentration of neon is clearly less. There is a small amount of simple hydrocarbons - ethane, acetylene and diacetylene - which are formed under the influence of solar ultraviolet radiation and charged particles arriving from Jupiter's magnetosphere. Carbon dioxide, carbon monoxide, and water in the upper atmosphere are thought to be due to collisions with Jupiter's atmosphere from comets such as Comet Shoemaker-Levy 9. Water cannot come from the troposphere because the tropopause acts as a cold trap , effectively prevents the rise of water to the level of the stratosphere.
Jupiter's reddish color variations may be due to compounds of phosphorus, sulfur, and carbon in the atmosphere. Since the color can vary greatly, it is assumed that the chemical composition of the atmosphere also varies from place to place. For example, there are "dry" and "wet" areas with different water vapor content.
Structure
Model of the internal structure of Jupiter: under the clouds - a layer of a mixture of hydrogen and helium about 21 thousand km thick with a smooth transition from the gaseous to liquid phase, then - a layer of liquid and metallic hydrogen 30-50 thousand km deep. Inside there may be a solid core with a diameter of about 20 thousand km.
At the moment, the following model of the internal structure of Jupiter has received the most recognition:
1. Atmosphere. It is divided into three layers:
a. an outer layer consisting of hydrogen;
b. middle layer consisting of hydrogen (90%) and helium (10%);
c. the lower layer, consisting of hydrogen, helium and impurities of ammonia, ammonium hydrosulfate and water, forming three layers of clouds:
a. above - clouds of frozen ammonia (NH3). Its temperature is about -145 °C, pressure is about 1 atm;
b. below - clouds of crystals of ammonium hydrosulfide (NH4HS);
c. at the very bottom - water ice and, possibly, liquid water, which is probably meant - in the form of tiny drops. The pressure in this layer is about 1 atm, the temperature is about -130 °C (143 K). Below this level, the planet is opaque.
2. Layer of metallic hydrogen. The temperature of this layer varies from 6300 to 21,000 K, and the pressure from 200 to 4000 GPa.
3. Stone core.
The construction of this model is based on the synthesis of observational data, the application of the laws of thermodynamics and the extrapolation of laboratory data on a substance under high pressure and at high temperature. The main assumptions underlying it are:
If we add to these provisions the laws of conservation of mass and energy, we get a system of basic equations.
Within the framework of this simple three-layer model, there is no clear boundary between the main layers, however, the regions of phase transitions are also small. Therefore, it can be assumed that almost all processes are localized, and this allows each layer to be considered separately.
Atmosphere
The temperature in the atmosphere does not increase monotonically. In it, as on Earth, one can distinguish the exosphere, thermosphere, stratosphere, tropopause, troposphere. In the uppermost layers the temperature is high; as you move deeper, the pressure increases, and the temperature drops to the tropopause; starting from the tropopause, both temperature and pressure increase as one goes deeper. Unlike the Earth, Jupiter does not have a mesosphere and a corresponding mesopause.
Quite a lot of interesting processes take place in Jupiter's thermosphere: it is here that the planet loses a significant part of its heat by radiation, it is here that aurorae are formed, it is here that the ionosphere is formed. The pressure level of 1 nbar is taken as its upper limit. The observed temperature of the thermosphere is 800-1000 K, and at the moment this factual material has not yet been explained within the framework of modern models, since the temperature in them should not be higher than about 400 K. The cooling of Jupiter is also a non-trivial process: a triatomic hydrogen ion (H3 + ), other than Jupiter, found only on Earth, causes strong emission in the mid-infrared at wavelengths between 3 and 5 µm.
According to direct measurements by the descent vehicle, the upper level of opaque clouds was characterized by a pressure of 1 atmosphere and a temperature of -107 °C; at a depth of 146 km - 22 atmospheres, +153 °C. Galileo also found "warm spots" along the equator. Apparently, in these places the layer of outer clouds is thin, and warmer inner regions can be seen.
Under the clouds there is a layer with a depth of 7-25 thousand km, in which hydrogen gradually changes its state from gas to liquid with increasing pressure and temperature (up to 6000 ° C). Apparently, there is no clear boundary separating gaseous hydrogen from liquid hydrogen. This may look something like the continuous boiling of the global hydrogen ocean.
layer of metallic hydrogen
Metallic hydrogen occurs at high pressures (about a million atmospheres) and high temperatures, when the kinetic energy of electrons exceeds the ionization potential of hydrogen. As a result, protons and electrons in it exist separately, so metallic hydrogen is a good conductor of electricity. The estimated thickness of the metallic hydrogen layer is 42-46 thousand km.
Powerful electric currents arising in this layer generate a giant magnetic field of Jupiter. In 2008, Raymond Dzhinloz from the University of California at Berkeley and Lars Stiksrud from University College London created a model of the structure of Jupiter and Saturn, according to which there is also metallic helium in their depths, which forms a kind of alloy with metallic hydrogen.
Nucleus
With the help of the measured moments of inertia of the planet, it is possible to estimate the size and mass of its core. At the moment, it is believed that the mass of the core is 10 masses of the Earth, and the size is 1.5 of its diameter.
Jupiter releases significantly more energy than it receives from the Sun. The researchers suggest that Jupiter has a significant supply of thermal energy, formed in the process of compression of matter during the formation of the planet. Previous models of the internal structure of Jupiter, trying to explain the excess energy released by the planet, allowed for the possibility of radioactive decay in its bowels or the release of energy when the planet is compressed under the influence of gravitational forces.
Interlayer processes
It is impossible to localize all processes within independent layers: it is necessary to explain the lack of chemical elements in the atmosphere, excess radiation, etc.
The difference in the content of helium in the outer and inner layers is explained by the fact that helium condenses in the atmosphere and enters deeper regions in the form of droplets. This phenomenon resembles the earth's rain, but not from water, but from helium. It has recently been shown that neon can dissolve in these drops. This explains the lack of neon.
Atmospheric movement
Animation of Jupiter's rotation, created from photographs from Voyager 1, 1979.
Wind speeds on Jupiter can exceed 600 km/h. In contrast to the Earth, where the circulation of the atmosphere occurs due to the difference in solar heating in the equatorial and polar regions, on Jupiter the effect of solar radiation on temperature circulation is insignificant; the main driving forces are the heat flows coming from the center of the planet, and the energy released during the rapid movement of Jupiter around its axis.
Based on ground-based observations, astronomers divided the belts and zones in the atmosphere of Jupiter into equatorial, tropical, temperate and polar. The heated masses of gases rising from the depths of the atmosphere in the zones under the influence of significant Coriolis forces on Jupiter are drawn along the meridians of the planet, and the opposite edges of the zones move towards each other. There is strong turbulence at the boundaries of zones and belts (downflow areas). To the north of the equator, flows in zones directed to the north are deflected by Coriolis forces to the east, and those directed to the south - to the west. In the southern hemisphere - respectively, on the contrary. The trade winds have a similar structure on Earth.
stripes
Jupiter bands in different years
A characteristic feature of the external appearance of Jupiter are its stripes. There are a number of versions explaining their origin. So, according to one version, the stripes arose as a result of the phenomenon of convection in the atmosphere of the giant planet - due to heating, and, as a result, raising some layers, and cooling and lowering others down. In the spring of 2010, scientists put forward a hypothesis according to which the stripes on Jupiter arose as a result of the influence of its satellites. It is assumed that under the influence of the attraction of satellites on Jupiter, peculiar “pillars” of matter were formed, which, rotating, formed stripes.
Convective currents, which carry internal heat to the surface, externally appear in the form of light zones and dark belts. In the area of light zones, there is an increased pressure corresponding to ascending flows. The clouds forming the zones are located at a higher level (about 20 km), and their light color is apparently due to an increased concentration of bright white ammonia crystals. The dark belt clouds below are believed to be red-brown ammonium hydrosulfide crystals and have a higher temperature. These structures represent downstream regions. Zones and belts have different speeds of movement in the direction of rotation of Jupiter. The orbital period varies by several minutes depending on the latitude. This leads to the existence of stable zonal currents or winds constantly blowing parallel to the equator in one direction. Velocities in this global system reach from 50 to 150 m/s and higher. At the boundaries of belts and zones, strong turbulence is observed, which leads to the formation of numerous vortex structures. The most famous such formation is the Great Red Spot, which has been observed on the surface of Jupiter over the past 300 years.
Having arisen, the vortex raises the heated masses of gas with vapors of small components to the surface of the clouds. The resulting crystals of ammonia snow, solutions and compounds of ammonia in the form of snow and drops, ordinary water snow and ice gradually sink in the atmosphere until they reach levels at which the temperature is high enough and evaporate. After that, the substance in the gaseous state again returns to the cloud layer.
In the summer of 2007, the Hubble telescope recorded dramatic changes in Jupiter's atmosphere. Separate zones in the atmosphere to the north and south of the equator turned into belts, and the belts into zones. At the same time, not only the forms of atmospheric formations changed, but also their color.
On May 9, 2010, amateur astronomer Anthony Wesley (eng. Anthony Wesley, also see below) discovered that one of the most visible and most stable formations in time, the South Equatorial Belt, suddenly disappeared from the face of the planet. It is at the latitude of the Southern equatorial belt that the Great Red Spot “washed” by it is located. The reason for the sudden disappearance of the southern equatorial belt of Jupiter is the appearance of a layer of lighter clouds above it, under which a strip of dark clouds is hidden. According to studies conducted by the Hubble telescope, it was concluded that the belt did not disappear completely, but simply appeared to be hidden under a layer of clouds consisting of ammonia.
big red spot
The Great Red Spot is an oval formation of variable size located in the southern tropical zone. It was discovered by Robert Hooke in 1664. At present, it has dimensions of 15 × 30 thousand km (the diameter of the Earth is ~12.7 thousand km), and 100 years ago, observers noted 2 times larger sizes. Sometimes it is not very clearly visible. The Great Red Spot is a unique long-lived giant hurricane in which the substance rotates counterclockwise and makes a complete revolution in 6 Earth days.
Thanks to research conducted in late 2000 by the Cassini probe, it was found that the Great Red Spot is associated with downdrafts (vertical circulation of atmospheric masses); the clouds are higher here and the temperature is lower than in other areas. The color of the clouds depends on the height: the blue structures are the top ones, the brown ones lie below them, then the white ones. Red structures are the lowest. The rotation speed of the Great Red Spot is 360 km/h. Its average temperature is -163 ° C, and between the marginal and central parts of the spot there is a difference in temperature of the order of 3-4 degrees. This difference is supposed to be responsible for the fact that atmospheric gases in the center of the spot rotate clockwise, while at the edges they rotate counterclockwise. An assumption has also been made about the relationship between temperature, pressure, movement and color of the Red Spot, although scientists still find it difficult to say exactly how it is carried out.
From time to time, collisions of large cyclonic systems are observed on Jupiter. One of them occurred in 1975, causing the red color of the Spot to fade for several years. At the end of February 2002, another giant whirlwind - the White Oval - began to be slowed down by the Great Red Spot, and the collision continued for a whole month. However, it did not cause serious damage to both vortices, as it happened on a tangent.
The red color of the Great Red Spot is a mystery. One possible reason could be chemical compounds containing phosphorus. In fact, the colors and mechanisms that give the appearance of the entire Jovian atmosphere are still poorly understood and can only be explained by direct measurements of its parameters.
In 1938, the formation and development of three large white ovals near 30° south latitude was recorded. This process was accompanied by the simultaneous formation of several more small white ovals - vortices. This confirms that the Great Red Spot is the most powerful of Jupiter's vortices. Historical records do not reveal such long-lived systems in the mid-northern latitudes of the planet. Large dark ovals have been observed near 15°N, but apparently the necessary conditions for the emergence of eddies and their subsequent transformation into stable systems like the Red Spot exist only in the Southern Hemisphere.
small red spot
The Great Red Spot and the Little Red Spot in May 2008 in a photograph taken by the Hubble Space Telescope
As for the three aforementioned white oval vortices, two of them merged in 1998, and in 2000 a new vortex merged with the remaining third oval. At the end of 2005, the vortex (Oval BA, English Oval BC) began to change its color, eventually acquiring a red color, for which it received a new name - the Little Red Spot. In July 2006, the Small Red Spot came into contact with its older "brother" - the Great Red Spot. However, this did not have any significant effect on both vortices - the collision was tangential. The collision was predicted in the first half of 2006.
Lightning
At the center of the vortex, the pressure is higher than in the surrounding area, and the hurricanes themselves are surrounded by low-pressure perturbations. According to images taken by the Voyager 1 and Voyager 2 space probes, it was found that at the center of such vortices, colossal lightning flashes thousands of kilometers long are observed. The power of lightning is three orders of magnitude higher than that of the earth.
Magnetic field and magnetosphere
Scheme of Jupiter's magnetic field
The first sign of any magnetic field is radio emission, as well as x-rays. By building models of ongoing processes, one can judge the structure of the magnetic field. So it was found that the magnetic field of Jupiter has not only a dipole component, but also a quadrupole, an octupole and other harmonics of higher orders. It is assumed that the magnetic field is created by a dynamo, similar to the earth. But unlike the Earth, the conductor of currents on Jupiter is a layer of metallic helium.
The axis of the magnetic field is inclined to the axis of rotation 10.2 ± 0.6 °, almost like on Earth, however, the north magnetic pole is located next to the south geographic one, and the south magnetic pole is located next to the north geographic one. The field strength at the level of the visible surface of the clouds is 14 Oe at the north pole and 10.7 Oe at the south. Its polarity is the opposite of the earth's magnetic field.
The shape of Jupiter's magnetic field is strongly flattened and resembles a disk (in contrast to the drop-shaped one of the Earth). The centrifugal force acting on the co-rotating plasma on one side and the thermal pressure of the hot plasma on the other stretch the lines of force, forming at a distance of 20 RJ a structure resembling a thin pancake, also known as a magnetodisk. It has a fine current structure near the magnetic equator.
Around Jupiter, as well as around most planets in the solar system, there is a magnetosphere - an area in which the behavior of charged particles, plasma, is determined by the magnetic field. For Jupiter, the sources of such particles are the solar wind and Io. Volcanic ash ejected by Io's volcanoes is ionized by solar ultraviolet radiation. This is how sulfur and oxygen ions are formed: S+, O+, S2+ and O2+. These particles leave the satellite's atmosphere, but remain in orbit around it, forming a torus. This torus was discovered by Voyager 1; it lies in the plane of Jupiter's equator and has a radius of 1 RJ in cross section and a radius from the center (in this case from the center of Jupiter) to the generatrix of 5.9 RJ. It is he who fundamentally changes the dynamics of Jupiter's magnetosphere.
Jupiter's magnetosphere. Magnetically trapped solar wind ions are shown in red in the diagram, Io's neutral volcanic gas belt is shown in green, and Europa's neutral gas belt is shown in blue. ENA are neutral atoms. According to the Cassini probe, obtained in early 2001.
The oncoming solar wind is balanced by the pressure of the magnetic field at distances of 50-100 planetary radii, without the influence of Io, this distance would be no more than 42 RJ. On the night side, it extends beyond the orbit of Saturn, reaching a length of 650 million km or more. Electrons accelerated in Jupiter's magnetosphere reach the Earth. If Jupiter's magnetosphere could be seen from the Earth's surface, then its angular dimensions would exceed the dimensions of the Moon.
radiation belts
Jupiter has powerful radiation belts. When approaching Jupiter, Galileo received a dose of radiation 25 times the lethal dose for humans. Radio emission from Jupiter's radiation belt was first discovered in 1955. The radio emission has a synchrotron character. Electrons in the radiation belts have a huge energy of about 20 MeV, while the Cassini probe found that the density of electrons in Jupiter's radiation belts is lower than expected. The flow of electrons in the radiation belts of Jupiter can pose a serious danger to spacecraft due to the high risk of equipment damage by radiation. In general, Jupiter's radio emission is not strictly uniform and constant - both in time and in frequency. The average frequency of such radiation, according to research, is about 20 MHz, and the entire frequency range is from 5-10 to 39.5 MHz.
Jupiter is surrounded by an ionosphere with a length of 3000 km.
Auroras on Jupiter
Jupiter's aurora pattern showing the main ring, aurorae and sunspots resulting from interactions with Jupiter's natural moons.
Jupiter shows bright, steady auroras around both poles. Unlike those on Earth, which appear during periods of increased solar activity, Jupiter's auroras are constant, although their intensity varies from day to day. They consist of three main components: the main and brightest region is relatively small (less than 1000 km wide), located about 16 ° from the magnetic poles; hot spots - traces of magnetic field lines connecting the ionospheres of satellites with the ionosphere of Jupiter, and areas of short-term emissions located inside the main ring. Aurora emissions have been detected in almost all parts of the electromagnetic spectrum from radio waves to X-rays (up to 3 keV), but they are brightest in the mid-infrared (wavelength 3-4 µm and 7-14 µm) and deep ultraviolet region of the spectrum (length waves 80-180 nm).
The position of the main auroral rings is stable, as is their shape. However, their radiation is strongly modulated by the pressure of the solar wind - the stronger the wind, the weaker the auroras. The aurora stability is maintained by a large influx of electrons accelerated due to the potential difference between the ionosphere and the magnetodisk. These electrons generate a current that maintains the synchronism of rotation in the magnetodisk. The energy of these electrons is 10 - 100 keV; penetrating deep into the atmosphere, they ionize and excite molecular hydrogen, causing ultraviolet radiation. In addition, they heat up the ionosphere, which explains the strong infrared radiation of the auroras and partly the heating of the thermosphere.
Hot spots are associated with three Galilean moons: Io, Europa and Ganymede. They arise due to the fact that the rotating plasma slows down near satellites. The brightest spots belong to Io, since this satellite is the main supplier of plasma, the spots of Europa and Ganymede are much fainter. Bright spots within the main rings that appear from time to time are thought to be related to the interaction of the magnetosphere and the solar wind.
large x-ray spot
Composite image of Jupiter from the Hubble and Chandra X-ray telescope - February 2007
In December 2000, the Chandra Orbital Telescope discovered a source of pulsating X-ray radiation at the poles of Jupiter (mainly at the north pole), called the Great X-ray Spot. The reasons for this radiation are still a mystery.
Models of Formation and Evolution
A significant contribution to our understanding of the formation and evolution of stars is made by observations of exoplanets. So, with their help, features common to all planets like Jupiter were established:
They are formed even before the moment of scattering of the protoplanetary disk.
Accretion plays a significant role in formation.
Enrichment in heavy chemical elements due to planetesimals.
There are two main hypotheses explaining the processes of the origin and formation of Jupiter.
According to the first hypothesis, called the "contraction" hypothesis, the relative similarity of the chemical composition of Jupiter and the Sun (a large proportion of hydrogen and helium) is explained by the fact that during the formation of planets in the early stages of the development of the Solar System, massive "clumps" formed in the gas and dust disk, which gave rise to planets, i.e. the sun and the planets were formed in a similar way. True, this hypothesis still does not explain the existing differences in the chemical composition of the planets: Saturn, for example, contains more heavy chemical elements than Jupiter, and that, in turn, is larger than the Sun. The terrestrial planets are generally strikingly different in their chemical composition from the giant planets.
The second hypothesis (the “accretion” hypothesis) states that the process of formation of Jupiter, as well as Saturn, took place in two stages. First, for several tens of millions of years, the process of formation of solid dense bodies, like the planets of the terrestrial group, went on. Then the second stage began, when for several hundred thousand years the process of gas accretion from the primary protoplanetary cloud to these bodies, which by that time had reached a mass of several Earth masses, lasted.
Even at the first stage, part of the gas dissipated from the region of Jupiter and Saturn, which led to some differences in the chemical composition of these planets and the Sun. At the second stage, the temperature of the outer layers of Jupiter and Saturn reached 5000 °C and 2000 °C, respectively. Uranus and Neptune reached the critical mass needed to start accretion much later, which affected both their masses and their chemical composition.
In 2004, Katharina Lodders from the University of Washington hypothesized that Jupiter's core consists mainly of some kind of organic matter with adhesive abilities, which, in turn, to a large extent influenced the capture of matter from the surrounding region of space by the core. The resulting stone-tar core "captured" gas from the solar nebula by its gravity, forming modern Jupiter. This idea fits into the second hypothesis about the origin of Jupiter by accretion.
Satellites and rings
Large satellites of Jupiter: Io, Europa, Ganymede and Callisto and their surfaces.
Jupiter's moons: Io, Europa, Ganymede and Callisto
As of January 2012, Jupiter has 67 known moons, the most in the solar system. It is estimated that there may be at least a hundred satellites. The satellites are given mainly the names of various mythical characters, one way or another connected with Zeus-Jupiter. Satellites are divided into two large groups - internal (8 satellites, Galilean and non-Galilean internal satellites) and external (55 satellites, also divided into two groups) - thus, in total 4 "varieties" are obtained. The four largest satellites - Io, Europa, Ganymede and Callisto - were discovered back in 1610 by Galileo Galilei]. The discovery of Jupiter's satellites served as the first serious factual argument in favor of the Copernican heliocentric system.
Europe
Of greatest interest is Europe, which has a global ocean, in which the presence of life is not excluded. Special studies have shown that the ocean extends 90 km deep, its volume exceeds the volume of the Earth's oceans. The surface of Europa is riddled with faults and cracks that have arisen in the ice shell of the satellite. It has been suggested that the ocean itself, and not the core of the satellite, is the source of heat for Europe. The existence of an under-ice ocean is also assumed on Callisto and Ganymede. Based on the assumption that oxygen could penetrate into the subglacial ocean in 1-2 billion years, scientists theoretically assume the existence of life on the satellite. The oxygen content in Europa's oceans is sufficient to support the existence of not only single-celled life forms, but also larger ones. This satellite ranks second in terms of the possibility of life after Enceladus.
And about
Io is interesting for the presence of powerful active volcanoes; the surface of the satellite is flooded with products of volcanic activity. Photographs taken by space probes show that Io's surface is bright yellow with patches of brown, red, and dark yellow. These spots are the product of Io's volcanic eruptions, consisting mainly of sulfur and its compounds; The color of eruptions depends on their temperature.
[edit] Ganymede
Ganymede is the largest satellite not only of Jupiter, but in general in the solar system among all the satellites of the planets. Ganymede and Callisto are covered with numerous craters, on Callisto many of them are surrounded by cracks.
Callisto
Callisto is also thought to have an ocean below the moon's surface; this is indirectly indicated by the Callisto magnetic field, which can be generated by the presence of electric currents in salt water inside the satellite. Also in favor of this hypothesis is the fact that the magnetic field of Callisto varies depending on its orientation to the magnetic field of Jupiter, that is, there is a highly conductive liquid under the surface of this satellite.
Comparison of the sizes of the Galilean satellites with the Earth and the Moon
Features of the Galilean satellites
All large satellites of Jupiter rotate synchronously and always face Jupiter with the same side due to the influence of the powerful tidal forces of the giant planet. At the same time, Ganymede, Europa and Io are in orbital resonance with each other. In addition, there is a pattern among the satellites of Jupiter: the farther the satellite is from the planet, the lower its density (Io has 3.53 g/cm2, Europa has 2.99 g/cm2, Ganymede has 1.94 g/cm2, Callisto has 1.83 g/cm2). It depends on the amount of water on the satellite: on Io it is practically absent, on Europa - 8%, on Ganymede and Callisto - up to half of their mass.
Minor moons of Jupiter
The rest of the satellites are much smaller and are irregularly shaped rocky bodies. Among them are those who turn in the opposite direction. Of the small satellites of Jupiter, Amalthea is of considerable interest to scientists: it is assumed that there is a system of voids inside it that arose as a result of a catastrophe that took place in the distant past - due to a meteorite bombardment, Amalthea broke up into parts, which then reunited under the influence of mutual gravity, but never became a single monolithic body.
Metis and Adrastea are the closest moons to Jupiter with diameters of approximately 40 and 20 km, respectively. They move along the edge of the main ring of Jupiter in an orbit with a radius of 128 thousand km, making a revolution around Jupiter in 7 hours and being the fastest satellites of Jupiter.
The total diameter of the entire satellite system of Jupiter is 24 million km. Moreover, it is assumed that Jupiter had even more satellites in the past, but some of them fell on the planet under the influence of its powerful gravity.
Satellites with reverse rotation around Jupiter
Jupiter's satellites, whose names end in "e" - Karma, Sinop, Ananke, Pasiphe and others (see Ananke group, Karme group, Pasiphe group) - revolve around the planet in the opposite direction (retrograde motion) and, according to scientists, formed not together with Jupiter, but were captured by him later. Neptune's satellite Triton has a similar property.
Interim moons of Jupiter
Some comets are temporary moons of Jupiter. So, in particular, the comet Kushida - Muramatsu (English) Russian. in the period from 1949 to 1961. was a satellite of Jupiter, having made two revolutions around the planet during this time. In addition to this object, at least 4 temporary moons of the giant planet are also known.
Rings of Jupiter
Rings of Jupiter (diagram).
Jupiter has faint rings discovered during Voyager 1's transit of Jupiter in 1979. The presence of rings was assumed back in 1960 by the Soviet astronomer Sergei Vsekhsvyatsky, based on a study of the far points of the orbits of some comets, Vsekhsvyatsky concluded that these comets could come from the ring of Jupiter and suggested that the ring was formed as a result of the volcanic activity of Jupiter's satellites (volcanoes on Io were discovered two decades later ).
The rings are optically thin, their optical thickness is ~10-6, and the particle albedo is only 1.5%. However, it is still possible to observe them: at phase angles close to 180 degrees (looking "against the light"), the brightness of the rings increases by about 100 times, and the dark night side of Jupiter leaves no light. There are three rings in total: one main, "spider" and a halo.
Photograph of Jupiter's rings taken by Galileo in direct diffused light.
The main ring extends from 122,500 to 129,230 km from the center of Jupiter. Inside, the main ring passes into a toroidal halo, and outside it contacts the arachnoid. The observed forward scattering of radiation in the optical range is characteristic of micron-sized dust particles. However, the dust in the vicinity of Jupiter is subjected to powerful non-gravitational perturbations, because of this, the lifetime of dust particles is 103 ± 1 years. This means that there must be a source of these dust particles. Two small satellites lying inside the main ring, Metis and Adrastea, are suitable for the role of such sources. Colliding with meteoroids, they generate a swarm of microparticles, which subsequently spread in orbit around Jupiter. Gossamer ring observations revealed two separate belts of matter originating in the orbits of Thebes and Amalthea. The structure of these belts resembles the structure of zodiac dust complexes.
Trojan asteroids
Trojan asteroids - a group of asteroids located in the region of the Lagrange points L4 and L5 of Jupiter. Asteroids are in 1:1 resonance with Jupiter and move with it in orbit around the Sun. At the same time, there is a tradition to call objects located near the L4 point by the names of Greek heroes, and near L5 - by Trojan ones. In total, as of June 2010, 1583 such facilities were opened.
There are two theories explaining the origin of the Trojans. The first asserts that they arose at the final stage of the formation of Jupiter (the accreting variant is being considered). Together with the matter, planetozimals were captured, on which accretion also took place, and since the mechanism was effective, half of them ended up in a gravitational trap. The disadvantages of this theory are that the number of objects that have arisen in this way is four orders of magnitude larger than the observed one, and they have a much larger orbital inclination.
The second theory is dynamic. 300-500 million years after the formation of the solar system, Jupiter and Saturn went through a 1:2 resonance. This led to a restructuring of the orbits: Neptune, Pluto and Saturn increased the radius of the orbit, and Jupiter decreased. This affected the gravitational stability of the Kuiper belt, and some of the asteroids that inhabited it moved to the orbit of Jupiter. At the same time, all the original Trojans, if any, were destroyed.
The further fate of the Trojans is unknown. A series of weak resonances of Jupiter and Saturn will cause them to move chaotically, but what this force of chaotic movement will be and whether they will be thrown out of their current orbit is difficult to say. In addition, collisions between each other slowly but surely reduce the number of Trojans. Some fragments can become satellites, and some comets.
Collisions of celestial bodies with Jupiter
Comet Shoemaker-Levy
A trail from one of the debris of comet Shoemaker-Levy, image from the Hubble telescope, July 1994.
Main article: Comet Shoemaker-Levy 9
In July 1992, a comet approached Jupiter. It passed at a distance of about 15 thousand kilometers from the upper boundary of the clouds, and the powerful gravitational effect of the giant planet tore its core into 17 large parts. This swarm of comets was discovered at Mount Palomar Observatory by Carolyn and Eugene Shoemaker and amateur astronomer David Levy. In 1994, during the next approach to Jupiter, all the fragments of the comet crashed into the planet's atmosphere at a tremendous speed - about 64 kilometers per second. This grandiose cosmic cataclysm was observed both from the Earth and with the help of space means, in particular, with the help of the Hubble Space Telescope, the IUE satellite and the Galileo interplanetary space station. The fall of the nuclei was accompanied by flashes of radiation in a wide spectral range, the generation of gas emissions and the formation of long-lived vortices, a change in Jupiter's radiation belts and the appearance of auroras, and a decrease in the brightness of Io's plasma torus in the extreme ultraviolet range.
Other falls
On July 19, 2009, the aforementioned amateur astronomer Anthony Wesley discovered a dark spot near Jupiter's South Pole. Later, this find was confirmed at the Keck Observatory in Hawaii. An analysis of the data obtained indicated that the most probable body that fell into the atmosphere of Jupiter was a stone asteroid.
On June 3, 2010 at 20:31 UT, two independent observers - Anthony Wesley (Eng. Anthony Wesley, Australia) and Christopher Go (Eng. Christopher Go, Philippines) - filmed a flash above the atmosphere of Jupiter, which is most likely a fall new, previously unknown body to Jupiter. A day after this event, no new dark spots were found in Jupiter's atmosphere. Observations have already been made with the largest Hawaiian instruments (Gemini, Keck and IRTF) and observations are planned with the Hubble Space Telescope. On June 16, 2010, NASA published a press release stating that the images taken by the Hubble Space Telescope on June 7, 2010 (4 days after the outbreak was detected) showed no signs of falling in the upper atmosphere of Jupiter.
On August 20, 2010 at 18:21:56 IST, an outburst occurred above Jupiter's cloud cover, which was detected by Japanese amateur astronomer Masayuki Tachikawa from Kumamoto Prefecture in a video he made. The day after the announcement of this event, confirmation was found from an independent observer Aoki Kazuo (Aoki Kazuo) - an amateur astronomer from Tokyo. Presumably, it could be the fall of an asteroid or comet into the atmosphere of a giant planet.
On March 13, 1781, English astronomer William Herschel discovered the seventh planet in the solar system - Uranus. And on March 13, 1930, American astronomer Clyde Tombaugh discovered the ninth planet in the solar system - Pluto. By the beginning of the 21st century, it was believed that the solar system included nine planets. However, in 2006, the International Astronomical Union decided to strip Pluto of this status.
There are already 60 known natural satellites of Saturn, most of which have been discovered using spacecraft. Most satellites are made up of rocks and ice. The largest satellite, Titan, discovered in 1655 by Christian Huygens, is larger than the planet Mercury. The diameter of Titan is about 5200 km. Titan orbits Saturn every 16 days. Titan is the only moon to have a very dense atmosphere, 1.5 times the size of Earth's, and consisting mostly of 90% nitrogen, with a moderate amount of methane.
The International Astronomical Union officially recognized Pluto as a planet in May 1930. At that moment, it was assumed that its mass was comparable to the mass of the Earth, but later it was found that the mass of Pluto is almost 500 times less than the Earth's, even less than the mass of the Moon. The mass of Pluto is 1.2 times 1022 kg (0.22 Earth masses). The average distance of Pluto from the Sun is 39.44 AU. (5.9 by 10 to the 12th degree km), the radius is about 1.65 thousand km. The period of revolution around the Sun is 248.6 years, the period of rotation around its axis is 6.4 days. The composition of Pluto supposedly includes rock and ice; the planet has a thin atmosphere composed of nitrogen, methane and carbon monoxide. Pluto has three moons: Charon, Hydra and Nyx.
In the late 20th and early 21st centuries, many objects were discovered in the outer solar system. It has become clear that Pluto is only one of the largest Kuiper belt objects known to date. Moreover, at least one of the objects of the belt - Eris - is a larger body than Pluto and 27% heavier than it. In this regard, the idea arose to no longer consider Pluto as a planet. On August 24, 2006, at the XXVI General Assembly of the International Astronomical Union (IAU), it was decided to henceforth call Pluto not a "planet", but a "dwarf planet".
At the conference, a new definition of the planet was developed, according to which planets are considered to be bodies revolving around a star (and not being a star themselves), having a hydrostatically balanced shape and "clearing" the area in the region of their orbit from other, smaller, objects. Dwarf planets will be considered objects that revolve around a star, have a hydrostatically equilibrium shape, but have not "cleared" the nearby space and are not satellites. Planets and dwarf planets are two different classes of solar system objects. All other objects revolving around the Sun and not being satellites will be called small bodies of the solar system.
Thus, since 2006, there have been eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Five dwarf planets are officially recognized by the International Astronomical Union: Ceres, Pluto, Haumea, Makemake, and Eris.
On June 11, 2008, the IAU announced the introduction of the concept of "plutoid". It was decided to call plutoids celestial bodies that revolve around the Sun in an orbit whose radius is greater than the radius of Neptune's orbit, whose mass is sufficient for gravitational forces to give them an almost spherical shape, and which do not clear the space around their orbit (that is, many small objects revolve around them ).
Since it is still difficult to determine the shape and thus the relation to the class of dwarf planets for such distant objects as plutoids, scientists recommended temporarily assigning to plutoids all objects whose absolute asteroid magnitude (brilliance from a distance of one astronomical unit) is brighter than +1. If it later turns out that the object assigned to the plutoids is not a dwarf planet, it will be deprived of this status, although the assigned name will be left. The dwarf planets Pluto and Eris were classified as plutoids. In July 2008, Makemake was included in this category. On September 17, 2008, Haumea was added to the list.
The material was prepared on the basis of information from open sources
Saturn is the sixth planet in the solar system. The second largest, and its density is so small that if you fill a huge reservoir with water and place Saturn there, then it will freely float on the surface without completely immersing itself in water. Saturn's main attraction is its rings, which are made up of dust, gas, and ice. A huge number of rings surround the planet, the diameter of which exceeds the diameter of the Earth several times.
What is Saturn?
First you need to figure out what kind of planet this is and what it is "eaten with". Saturn is the sixth planet from the Sun, named after the ancient Roman Greeks called him Kronos, the father of Zeus (Jupiter). At the farthest point of the orbit (aphelion), the distance from the sun is 1,513 billion km.
A planetary day is only 10 hours and 34 minutes, but a planetary year is 29.5 Earth years long. The atmosphere of the gas giant consists mainly of hydrogen (it accounts for 92%). The remaining 8% are impurities of helium, methane, ammonia, ethane, etc.
Launched in 1977, Voyager 1 and Voyager 2 reached the orbit of Saturn a couple of years ago and provided scientists with invaluable information about this planet. Winds were observed on the surface, whose speed reached 500 m / s. For example, the strongest wind on Earth reached only 103 m/s (New Hampshire,
Like the Great Red Spot on Jupiter, there is a Great White Oval on Saturn. But the second appears only every 30 years, and its last appearance was in 1990. In a couple of years we will be able to watch him again.
Size ratio of Saturn and Earth
How many times larger is Saturn than Earth? According to some reports, only in diameter Saturn exceeds our planet by 10 times. In terms of volume, 764 times, i.e. Saturn can accommodate exactly this number of our planets. The width of Saturn's rings exceeds the diameter of our blue planet by 6 times. He is so gigantic.
Distance from Earth to Saturn
First you need to take into account the fact that all the planets of the solar system do not move in a circle, but in ellipses (ovals). There are moments when there is a change in distance from the Sun. It can get closer, it can move away. On Earth, this is clearly visible. This is called the change of seasons. But here the rotation and inclination of our planet relative to the orbit plays a role.
Therefore, the distance from Earth to Saturn will vary considerably. Now you will know how. Using scientific measurements, it has been calculated that the minimum distance from Earth to Saturn in kilometers is 1195 million, while the maximum is 1660 million km.
As you know, the speed of light (according to Einstein's theory of relativity) is an insurmountable limit in the Universe. It seems to us unattainable. But on a cosmic scale, it is negligible. In 8 minutes, light travels the distance to the Earth, which is 150 million km (1 AU). The distance to Saturn has to be overcome in 1 hour and 20 minutes. It's not that long, you say, but just think that the speed of light is 300,000 m/s!
If you take a rocket as a means of transportation, it will take years to overcome the distance. Spacecraft aimed at studying the giant planets took from 2.5 to 3 years. At the moment they are outside the solar system. Many scientists believe that the distance from Earth to Saturn can be overcome in 6 years and 9 months.
What awaits a person at Saturn?
Why do we even need this hydrogen planet, where life would never have originated? Saturn is interested in scientists for its moon called Titan. The largest moon of Saturn and the second largest in the solar system (after Jupiter's Ganymede). It interested scientists no less than Mars. Titan is larger than Mercury and even has rivers on its surface. True, the rivers are from and ethane.
The force of gravity on a satellite is less than on Earth. The main element present in the atmosphere is hydrocarbon. If we manage to get to Titan, this will become a very acute problem for us. But tight suits will not be needed. Only very warm clothes and an oxygen tank. Given the density and gravity of Titan, it's safe to say that humans would be able to fly. The fact is that in such conditions our body can freely float in the air, without strong resistance from gravity. We will need only the usual model wings. And even if they break down, a person can easily "saddle" the solid surface of the satellite without any problems.
For the successful settlement of Titan, it will be necessary to build entire cities under hemispherical domes. Only then will it be possible to recreate a climate similar to the earth's, for more comfortable living and growing the necessary food, as well as extracting valuable mineral resources from the bowels of the planet.
The shortage of sunlight will also be an acute problem, because the Sun near Saturn seems small. A replacement for solar panels will be hydrocarbons, which cover the planet in abundance with whole seas. From it the first colonizers will receive energy. Water is found deep below the moon's surface in the form of ice.
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Distance from Sun to Jupiter in kilometers in the photo: description of the position in the solar system, elliptical orbit, retrograde Jupiter, flight time to the planet.
Jupiter- the largest planet in the solar system, which can be considered, despite the great distance. Features of its orbit can be seen in the photo, where the distances from the Sun and the Earth are marked.
The planets travel in an elliptical orbital path, so the distance between them is always different. If located at the nearest point, then 588 million km. In this position, the planet even outshines Venus in brightness. At the maximum distance, the distance is 968 million km.
The gas giant takes 11.86 million km for one rotation around the star. The Earth on its way gets to Jupiter every 398.9 days. This retrograde led to problems in models of the solar system, where ideal circular orbits did not agree with the loop of Jupiter and other planets. Johannes Kepler guessed about elliptical paths.
Distance from Jupiter to the Sun?
On average, the distance from the Sun to Jupiter is 778 million km, but due to the ellipticity, the planet is able to approach 741 million km and move away 817 million km.
A center of mass is established between two rotating celestial bodies. Although we say that all the planets orbit the Sun, in fact they are aimed at a specific point of mass. For many planets, this center is located inside the star. But Jupiter is distinguished by an enviable massiveness, therefore for it the point is located outside the solar diameter. Now you know more about the distance from the Sun to the planet Jupiter in kilometers.
How long is the flight to Jupiter?
The flight speed to Jupiter depends on several factors: fuel supply, the location of the planets, speed, the use of a gravitational slingshot.
Galileo set off in 1989 and arrived 6 years later, traveling 2.5 billion miles. He had to go around Venus, Earth and the asteroid Gaspra. Voyager 1 launched in 1977 and arrived in 1979 because it traveled when the planets were in perfect alignment.
New Horizons flew direct in 2006 and arrived in 13 months. Juno, launched in 2011, took 5 years to complete.
ESA plans to launch the JUICE mission in 2022, whose journey will take 7.6 years. NASA wants to send a ship to Europe in the 2020s, which will take 3 years.
When a person is going to drive his own car to an unfamiliar city, the first thing to do is find out the distance to it in order to estimate travel time and stock up on gasoline. The path traveled on the road will not depend on whether you go on the road in the morning or in the evening, today or in a couple of months. With space travel, the situation is somewhat more complicated and the distance to Jupiter, measured yesterday, in six months will be one and a half times more, and then it will begin to decrease again. On Earth, it would be very inconvenient to travel to a city that itself is constantly moving.
The average distance from our planet to the gas giant is 778.57 million km, but this figure is about as relevant as information about the average temperature in a hospital. The fact is that both planets move around the Sun (or, more precisely, around the center of mass of the solar system) in elliptical orbits, and with different periods of revolution. For the Earth, it is equal to one year, and for Jupiter, it is almost 12 years (11.86 years). The minimum possible distance between them is 588.5 million km, and the maximum is 968.6 million km. The planets, as it were, ride on a swing, now approaching, then moving away.
The Earth moves with a greater orbital speed than Jupiter: 29.78 km / s versus 13.07 km / s, and is much closer to the center of the solar system, and therefore catches up with it every 398.9 days, coming closer. Given the ellipticity of the trajectories of motion, there are points in outer space where the distance between the planets becomes almost minimal. For the Earth-Jupiter pair, the period of time after which they regularly approach each other in this way is about 12 years.
Great confrontations
Such moments of time are usually called the dates of great confrontations. These days, Jupiter surpasses all celestial objects in the starry sky in its brightness, approaching the glow of Venus, and with the help of a small telescope or binoculars, it becomes possible to observe not only the planet itself, but even its satellites. Therefore, astronomers and simply connoisseurs of the beauty of the starry sky are looking forward to confrontations in order to take a closer look at a distant and little-studied cosmic body and, perhaps, even discover something hitherto unknown to science.
Another unique opportunity to observe Jupiter in the most comfortable conditions for an earthly observer will present itself in the last ten days of September 2022. At such moments on the surface of the planet, with the help of a small telescope, you can clearly see the famous Red Spot, the stripes on the disk of a celestial body, various vortex flows in them, and much more. Anyone who once in his life looked through a telescope at this planet, intriguing consciousness, will strive to do it again and again.
Depart later to arrive early
Inside the Great Red Spot
Knowing the kinematics of the planets and the planned speed of the spacecraft, it is possible to choose the optimal date for the launch of the launch vehicle in order to fly to Jupiter as quickly as possible, spending less fuel on it. To be more precise, it is not an interplanetary station that flies to a celestial body, but the two of them move to the meeting point, only the planet's route has not changed for millennia, and the trajectory of the aircraft can be chosen. There are options when the device, which took off later, will be able to reach the target earlier, therefore, in order to realize them, they strive to build a rocket by a date suitable for launch. There are times when it is more profitable to fly longer, but then use a "free" source of energy during acceleration and maneuvers - the gravitational attraction of other planets.
Planet exploration
Eight space missions have already taken part in the study of Jupiter, and the ninth, Juno, is underway. The start date of each of them was chosen taking into account the chosen route.
So, the Galileo orbital station, before becoming an artificial satellite of Jupiter, spent more than six years on the road, but managed to visit Venus and a couple of asteroids, and also flew past the Earth twice.
But the spacecraft "New Horizons" reached the gas giant in just 13 months, since its main goal is much further - this is Pluto and the Kuiper belt.
