Jupiter is one of the five planets in the solar system that can be seen in the night sky without any optical instruments. Still having no idea of its size, ancient astronomers named it the supreme Roman deity.
Meet Jupiter
Jupiter's orbit is 778 million km away from the Sun. A year there lasts 11.86 Earth years. The planet makes a complete rotation around its axis in just 9 hours 55 minutes, and the rotation speed is different at different latitudes, and the axis is almost perpendicular to the orbital plane, as a result of which seasonal changes are not observed.
Jupiter's surface temperature is 133 degrees Celsius (140 K). The radius is more than 11, and the mass is 317 times the radius and mass of our planet. The density (1.3 g/cm3) is commensurate with the density of the Sun and much less than the density of the Earth. The force of gravity on Jupiter is 2.54 times, and the magnetic field is 12 times greater than similar terrestrial parameters. The temperature during the day on Jupiter is no different from the night. This is due to a significant distance from the Sun and powerful processes occurring in the bowels of the planet.
EruOptical research of the fifth planet was discovered in 1610 by G. Galileo. It was he who discovered the four most massive satellites of Jupiter. To date, 67 cosmic bodies are known to be part of the giant's planetary system.
Research History
Until the 1970s, the planet was studied using ground-based and then orbital means in the optical, radio and gamma bands. The temperature of Jupiter was first estimated in 1923 by a group of scientists from the Lowell Observatory (Flagstaff, USA). Using vacuum thermocouples, the researchers found that the planet is "definitely a cold body." Photoelectric observations of Jupiter's occultation of stars and spectroscopic analysis made it possible to draw a conclusion about the composition of its atmosphere.
Subsequent flights of interplanetary vehicles refined and significantly expanded the accumulated information. Unmanned missions "Pioneer-10; 11" in 1973-1974. for the first time they transmitted pictures of the planet from a close distance (34 thousand km), data on the structure of the atmosphere, the presence of a magnetic and radiation belt. Voyager (1979), Ulysses (1992, 2000), Cassini (2000), and New Horizons (2007) have made improved measurements of Jupiter and its planetary system, and Galileo (1995-2003) and Juno (2016) joined the ranks of artificial satellites of the giant.
Internal structure
The core of the planet with a diameter of about 20 thousand km, consisting ofa small amount of rock and metallic hydrogen, is under a pressure of 30-100 million atmospheres. The temperature of Jupiter in this zone is about 30,000 ˚С. The mass of the core is from 3 to 15% of the total mass of the planet. The generation of thermal energy by Jupiter's core is explained by the Kelvin-Helmholtz mechanism. The essence of the phenomenon is that with a sharp cooling of the outer shell (the surface temperature of the planet Jupiter is -140˚С), a pressure drop occurs, causing compression of the body and subsequent heating of the core.
The next layer, 30 to 50 thousand km deep, is a substance of metallic and liquid hydrogen mixed with helium. With distance from the core, the pressure in this region decreases to 2 million atmospheres, the temperature of Jupiter drops to 6000 ˚С.
The structure of the atmosphere. Layers and composition
There is no clear boundary between the surface of the planet and the atmosphere. For its lower layer - the troposphere - scientists took a conditional area in which the pressure corresponds to the earth's. Further layers, as they moved away from the "surface", settled down in the following order:
- Stratosphere (up to 320 km).
- Thermosphere (up to 1000 km).
- Exosphere.
There is no single answer to the question of what temperature is on Jupiter. Violent convection processes occur in the atmosphere, caused by the internal heat of the planet. The observed disk has a pronounced striped structure. In white stripes (zones) air masses rush up, in dark (belts) they go down,forming convective cycles. In the upper layers of the thermosphere, the temperature reaches 1000 ˚С, and as it moves deeper and pressure increases, it gradually drops to negative values. As Jupiter reaches the troposphere, Jupiter's temperature begins to rise again.
The upper layers of the atmosphere are a mixture of hydrogen (90%) and helium. The composition of the lower ones, where the main formation of clouds occurs, also includes methane, ammonia, ammonium hydrosulfate and water. Spectral analysis shows traces of ethane, propane and acetylene, hydrocyanic acid and carbon monoxide, phosphorus and sulfur compounds.
Cloud Tiers
Different colors of Jupiter's clouds indicate the presence of complex chemical compounds in their composition. Three tiers are clearly visible in the cloud structure:
- Top - saturated with crystals of frozen ammonia.
- Ammonium hydrosulfide content increases significantly on average.
- In the bottom - water ice and possibly tiny drops of water.
Some atmospheric models developed by scientists and researchers do not exclude the presence of another cloud layer consisting of liquid ammonia. The ultraviolet radiation of the Sun and the powerful energy potential of Jupiter initiate the flow of numerous chemical and physical processes in the planet's atmosphere.
Atmospheric phenomena
The boundaries of zones and belts on Jupiter are characterized by strong winds (up to 200 m/sec). From the equator to the poles of the directionstreams alternate periodically. The wind speed decreases with increasing latitude and is practically absent at the poles. The scale of atmospheric phenomena on the planet (storms, lightning discharges, aurora borealis) is an order of magnitude greater than on Earth. The famous Great Red Spot is nothing more than a giant storm, larger than two Earth's disks in area. The spot slowly drifts from side to side. Over a hundred years of observation, its apparent size has halved.
The Voyager mission also found that the centers of atmospheric vortex formations are replete with lightning flashes, the linear dimensions of which exceed thousands of kilometers.
Is there life on Jupiter?
The question will cause bewilderment for many. Jupiter - a planet whose surface temperature (as well as the existence of the surface itself) has an ambiguous interpretation - can hardly be the "cradle of the mind." But the existence of biological organisms in the atmosphere of a giant back in the 70s of the last century, scientists did not exclude. The fact is that in the upper layers the pressure and temperature are very favorable for the occurrence and course of chemical reactions involving ammonia or hydrocarbons. Astronomer K. Sagan and astrophysicist E. Salpeter (USA), guided by physical and chemical laws, made a bold assumption about life forms, the existence of which is not excluded under these conditions:
- Sinkers are microorganisms that can multiply rapidly and in large numbers, allowing populations to survive in changing environments.conditions of convective currents.
- Floaters are giant balloon-like creatures. Releasing heavy helium, drifting in the upper layers.
Anyway, neither Galileo nor Juno found anything of the sort.
