Jupiter is one of the four gas planets (also known as wood-like planets): a planet that is not mainly composed of solid matter. It is the largest planet in the solar system with an equatorial diameter of 142984 km. The density of Jupiter is 1.326 g/cm? , ranked second among gas planets, but far below the four categories of terrestrial planets in the solar system.
structure component
Jupiter's upper atmosphere consists of about 88-92% hydrogen and about 8- 12% helium by volume or gas molecular percentage. Because the mass of helium atom is four times that of hydrogen atom, when discussing the mass composition of Jupiter, the proportion will change: hydrogen and helium account for 75% and 24% of the total mass in the atmosphere respectively, and the remaining 1% is other elements, including trace methane, water vapor, ammonia and silicon compounds. In addition, Jupiter also contains trace amounts of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, sulfur and other substances. There are frozen ammonia crystals in the outermost layer of the atmosphere. Through infrared and ultraviolet measurements, trace amounts of benzene and hydrocarbons were also found on Jupiter.
great red spot
Jupiter may have a stone core covered with a layer of liquid metal hydrogen, containing a small amount of helium, mainly hydrogen. In the inner core, most planetary materials are concentrated in the form of liquid hydrogen. The most common formal foundation on Jupiter may only exist under the pressure of 4 billion Pa, which is the internal environment of Jupiter (and Saturn). Liquid metallic hydrogen consists of ionized protons and electrons.
Under the temperature and pressure inside Jupiter, hydrogen is liquid, not gaseous, which makes it the electron director and source of Jupiter's magnetic field. Jupiter's magnetic field strength is about 10 gauss, which is 10 times larger than that of the earth. This layer may also contain some helium and some ice. Jupiter is also one of the strongest radio sources known in the sky.
Inside gaseous planets (Jupiter, Saturn, Uranus, Neptune)
Due to the Kelvin-Helmholtz mechanism, the temperature and pressure inside Jupiter increase steadily towards the core. On the "surface" with a pressure of 10 Pa, the temperature is about 340 k (67 c; ; 152 F). In the region of hydrogen phase transition-the temperature reaches the critical point-hydrogen becomes metal, and the temperature is considered as10000 k (9700 C; 17500 F), and the pressure is 200GPa. The temperature of the core boundary is estimated to be 36,000 K (35,700 C; 64300°F), and the internal pressure is about 3000-4500 GPA.
Jupiter structure diagram
If you put on a good enough spacesuit and come over Jupiter, you will feel your weight gain rapidly. What you see is Jupiter's violent atmosphere, which is divided into strips and blows in two adjacent opposite directions. When you first enter Jupiter's atmosphere, you will be confused by strong winds. Then you fall straight, you will feel that the greater the air pressure, the heavier the weight, which can be equivalent to 2.5 times that of the earth. Jupiter's atmosphere is 3000 kilometers thick, and people will be squashed first and then fall low.
If you don't squash it, you will see a series of lights, which are actually Jupiter lightning. When you descend to 3000 kilometers, you will find that the surrounding atmosphere is very thick, just like liquid, and then it is really liquid. This is a sea of liquid hydrogen, with a thickness of 27 thousand kilometers, and the temperature here is so high that people can't stand it.
Jupiter structure
Further down is metallic hydrogen, and there may be a stone core, which is equivalent to the mass of 10- 15 earths. On the inner core, most of the planetary materials are gathered, and the temperature is as high as 30,000 degrees, which is higher than the temperature on the surface of the sun. The substance here is mainly liquid hydrogen, which is roughly the internal environment of Jupiter.
So, what's under Jupiter's clouds?
The latest achievements of the spacecraft have been published in four articles published in Nature and an accompanying article News and Views. Moreover, for the first time, we have a good understanding of what happened under the cloud top.
Jonathan Fortney of the University of California, Santa Cruz, said in an interview: "This is the first time to see how gas giants work inside." He wrote this article News and Views.
Although these four articles focus on different research fields, they basically have a similar theme-some key features of Jupiter.
One of the main findings is that we now know how far Jupiter's atmosphere extends, 3000 kilometers (1860 miles) from the cloud top, which is much larger than expected. Once it reaches this depth, the composition of the planet will change dramatically.
People imagine a lot of Jupiter under clouds. According to these papers, it seems that at this depth, the interior of the planet behaves like a solid-although it is not actually a solid. On the contrary, it is a fluid mixture of hydrogen and helium, rotating like a solid.
"Our research results also show that the planet will rotate in the form of a rigid body under the wind of 3,000 kilometers, and all this information will have a profound impact on our understanding of the interior of the planet, so that we can understand its formation more closely," said Amina Miguel of Leiden University in the Netherlands, one of the authors of the paper.
Jupiter is famous for its cloud belt. We can see that these clouds cover the planet, which was first discovered by Galileo 400 years ago. But scientists are not sure how far these belts extend. According to these latest results, these clouds seem to stop at 3000 kilometers, thus forming a more uniform shape. The pressure at its core is about 100000 times of our pressure on the earth.
"Galileo saw these stripes in Jupiter's atmosphere many centuries ago, so this is definitely something we have wanted to know for a long time, and we are all excited about the result." Miguel added.
Another important discovery of this study is that Jupiter's gravitational field is asymmetric between north and south. This is unexpected for such a rapidly rotating and turbulent planet. This seems to be caused by various winds and atmospheric flows on the earth.
The researchers also found that Jupiter's atmosphere contains about 1% of the planet's mass, which is equivalent to three earths, which is very huge. In contrast, the earth's atmosphere accounts for only one millionth of the earth's total mass.
"This result is surprising because it shows that Jupiter's atmospheric quality is very large, much deeper than we expected." Yohai Kaspi of Weizmann Institute of Science in Rehovot, Israel, said.
They found that the cyclones at the poles formed a continuous polygon pattern, and eight cyclones raged around a central cyclone at the North Pole. In Antarctica, there are five cyclones doing the same thing.