What is the largest planet in the universe? Uncovering the mystery of "super Jupiter"

Author: Duan Yuechu and Huang Xianghong

There are many amazing celestial bodies in the vast universe, and super Jupiters are one of them. In recent years, the major discoveries made by the Webb Space Telescope have given us a deeper understanding of super Jupiters.

The Webb Space Telescope has discovered a super-Jupiter around a nearby star, a discovery that has attracted widespread attention in the scientific community. The planet has roughly the same diameter as Jupiter, but is six times more massive, and has a hydrogen-rich atmosphere that is somewhat similar to Jupiter. However, one of its most notable features is its extremely long orbital period.

Why is the orbital period of a super Jupiter so long? This is the result of the combined effect of many factors. First, its distance from the star is 15 times the distance from the Earth to the Sun. Such a long distance makes the planet relatively less affected by the star's gravity, resulting in a slower orbital speed, which takes longer to complete an orbit around the star. Secondly, the mass distribution of the star and the planet itself also plays a role. If the mass of the star is small, the gravitational bond to the planet is relatively weak; and the super Jupiter itself has a large mass and moves slower under the same gravitational conditions, all of which lead to a longer orbital period. In addition, the environment of the galaxy and the interference of other celestial bodies, such as the gravitational influence of other stars in a multi-star system, may also make its orbit more complex and long.

So, what impact does such a long orbital period have on the formation and evolution of super Jupiters? During the formation process, a longer orbital period means that the planet has more time to capture matter from the vast space, thus potentially forming a larger mass. But on the other hand, due to the distance from the star, the distribution of matter is relatively sparse, which may also cause the instability of the material supply during the formation process, increasing the difficulty and uncertainty of formation.

In terms of evolution, the extremely long orbital period causes super Jupiters to receive relatively little stellar radiation. This makes their surface temperature lower and the physical and chemical processes in their atmosphere relatively slow. The composition and structure of their atmosphere may therefore be very different from those of planets with shorter orbital periods, which in turn affects the planet's climate and weather patterns.

Next, let's take a closer look at the composition and structure of the atmosphere of a super Jupiter. The latest research has found that in addition to the common components such as hydrogen, helium, methane, ammonia and water, some relatively rare substances, such as inert gases such as neon and xenon, have been detected in the atmosphere of a super Jupiter. Although the proportion of these rare gases is relatively low, they are of great significance for understanding the formation and evolution of the atmosphere.

In terms of the structure of the atmosphere, scientists have discovered that the atmosphere of a super Jupiter has an obvious multi-layer structure. In the bottom layer close to the surface of the planet, the temperature and pressure are extremely high. The clouds here are mainly composed of ammonium sulfide and water, forming a thick and complex cloud system. In the middle atmosphere, the methane content is relatively high, which may form a unique photochemical reaction and produce some complex organic molecules. In the upper atmosphere, there is a strong ionization phenomenon in the thin gas, forming a gorgeous scene similar to the Earth's aurora.

The composition and structure of the atmosphere of a super-Jupiter have a crucial impact on its climate and weather. From a compositional perspective, the abundance of gases such as hydrogen and helium determines the basic physical properties of the atmosphere. The presence of hydrogen gives the atmosphere a high heat capacity, which exhibits a buffering effect when absorbing and releasing heat. Helium is relatively stable, but its distribution and concentration also affect the overall density and pressure distribution of the atmosphere. The presence of compounds such as methane, ammonia and water participates in complex chemical processes. For example, methane may undergo photochemical reactions under certain conditions, affecting the chemical composition and energy balance of the atmosphere. The phase change of water plays a key role in the transfer and storage of heat, thereby affecting the stability and changing trends of the climate.

In terms of structure, the layered characteristics of the atmosphere directly affect the transmission of energy and matter. Thick clouds close to the surface can block the penetration of stellar radiation, resulting in uneven distribution of heat received by the planet's surface. The different reactions of the upper, thin gas layers to ultraviolet and cosmic rays may cause atmospheric ionization and electromagnetic phenomena, which in turn affect the atmospheric circulation patterns. The depth and pressure gradient of the atmosphere affect the vertical movement of the atmosphere. Deeper atmospheres may produce more intense convection, leading to large-scale storms and air flow activities. The temperature differences and density gradients between different gas layers drive the atmospheric circulation, forming complex wind systems and climate zones. For example, strong atmospheric circulation may lead to huge and persistent storm systems, similar to the Great Red Spot on Jupiter. The condensation and evaporation of different components under different temperature and pressure conditions will produce precipitation phenomena of special forms and intensities.

However, the study of super Jupiters is still ongoing, and there are still many unknowns waiting for us to explore. Scientists have long speculated that there is a large planet around this star 12 light years away from us, but they did not expect it to be so large and so far away from the star. 12 light years is an unimaginable distance for humans, and one light year is equivalent to 5.8 trillion miles. The new observations show that the planet orbits the star Epsilon Indi A, which is part of a triple star system.

An international team led by Elizabeth Matthews of the Max Planck Institute for Astronomy in Germany collected the images last year and published their findings in the journal Nature on July 24 this year. In order to directly observe this ancient and cold gas giant planet, astronomers used a special sunshade on the Webb telescope to block the starlight. With this ingenious technical means, the planet can be seen as a bright spot in infrared light, which is undoubtedly a rare and challenging astronomical observation feat.

It is worth mentioning that this star is very close to our solar system and is very bright, and can even be seen with the naked eye in the southern hemisphere. But unfortunately, don't expect life to exist on this super Jupiter. As Matthews explained in an email: "This is a gas giant planet without a hard surface or liquid water ocean." She also said that this solar system is unlikely to have more gas giant planets, but perhaps there are some small rocky worlds lurking inside it, which leaves endless reverie and exploration space for future research.

The discovery of the super-Jupiter by the Webb Space Telescope has once again broadened humanity's understanding of the diversity of planets in the universe. It makes us realize that there are countless mysteries waiting for us to uncover in the vast universe. I believe that with the continuous advancement of science and technology and the unremitting efforts of astronomers, our understanding of the universe will become more in-depth and comprehensive. The discovery of this super-Jupiter is only a small step in the human exploration of the universe, but it is also an extremely important step, inspiring us to continue to bravely move forward into the unknown depths of the universe.