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How Are Planets Made?

There are several ways to answer the question, “how are planets made?” Models, observations, chemical composition, structure, and more are just a few of the ways we know the planets are created. Each of these methods relies on a different combination of observations and models to understand planets and their composition. This article explores each of these processes. But do these processes match up in all cases? Let’s find out!


When building a model of the earth, the sun, and planets, you’ll need several things. You’ll need some mounting material, such as twine or string, and some dowel rods for attaching the planets. First, determine which colors represent which planet. For the sun, yellow should be used, while danube or dark blue is appropriate for Mercury. For the Earth, terra-cotta or green is appropriate, and red, white, or purple will do for Neptune and Pluto.

You’ll need a way to calculate the scale of your model. To calculate the distances between planets, you’ll need to multiply all distances by a factor called the scale factor. In the case of Earth, that factor is 235 cm. Using the same formula, you’ll need to multiply all distances by a factor called the scale factor. The resulting distance will be 235,183 cm for Earth.

Once you’ve determined the size and shape of each planet, you’ll need to make a model of the solar system. These models can be in the form of hanging mobiles or mounted on a stationary base. They’re important because they help explain the relative sizes of the planets and the distances between them. Some materials for solar system models include round fruit, plastic foam balls, or cardboard. Then you’ll want to add citations to your model so that you can check your work.


Observations of how planets are formed are rapidly increasing in number and quality, thanks to recent technological advances. Understanding how planets are made may provide insight into our past and may also help narrow down the search for life elsewhere in the Universe. Planet formation is a complex process, requiring the careful study of countless variables. For example, the initial composition of a protoplanetary disk may have a prebiotic chemistry that we wouldn’t expect to see on Earth. However, it’s possible that the host star’s X-rays could destroy unprotected life and strip planetary atmospheres.

During the early stages of planet formation, the material in a nebula swirled around a young star, accumulating through accretion. Over millions of years, these objects build up to full-size planets. In some cases, the largest bodies capture the gassy atmosphere of nearby planets to form giant gas giants. This core accretion model does not work well for planets in tight orbits around stars, so newer theories propose that gas giants migrate to or away from their star, as solar systems dynamically evolve. In other scenarios, they are expelled into interstellar space.

The dominant model of planet formation predicts that planets form a solid core first, and then accrete gas from the protoplanetary disk. But despite the fact that Earth and Neptune failed to grow massive enough to become gas giants, their solid cores are much more massive. These results, combined with other astronomical data, indicate that small rocky worlds are more likely to form on planets with less gas.

Chemical composition

Our knowledge of the chemical composition of planets is only partial. The composition of planets is determined by gas-trapping and condensation in water ice. These processes take place on the surfaces of refractory grains. The temperature, surface density, and partial pressures of volatile molecules determine the thermodynamic conditions. The resulting compositions of planets are crucial to understanding our solar system and the conditions that support life on other worlds.

The chemical composition of planets has important implications for the formation and differentiation of planets. Migration smooths the differences in composition of bodies formed at varying distances from their host stars. Planets formed in situ will retain specific ratios of elements. For instance, migration does not affect the Fe/Si or Mg/Si ratios. On the other hand, migration can increase or decrease the C/O ratio because most of the C-bearing species are volatile.

Previous research into the chemical composition of planet-forming disks was limited to detecting a few chemical elements in gas particles. To advance our understanding of planet-forming disks, DISCO developed a complementary tool called CAM. This tool is capable of measuring the abundance of many chemical elements. The DISCO project is now preparing the results of this work for publication. We can test these predictions with future measurements of exoplanets by the James Webb Space Telescope and other upcoming space telescopes.


Conventional analysis of planetary structures neglects the connection between the disk-like region and the vapor phase. This region contains a large mass of low-density material. The conventional model of planet structure assumes that the bulk density is made up of condensed material. Hence, the true surface density of the disk-like region is not known. But, the model shows that it may have a very high density.

A planetary body may have different silicate specific entropies, but the total AM of the entire structure may be the same. The pressure field in Figure 5a and b is represented by colored contours. Interpolation was done the same way as in Figure 4. Black dots in Figure 5b and e show radial angular velocity and specific angular momentum, respectively. For instance, a planet with high AM will have low SRE, while a planet with low SEM will rotate a solid body.

The atmospheres of planets are composed of various compounds of oxygen. For example, ocean planets may have silicate cores veiled by H/He-rich atmospheres. These compositions may be responsible for resolving degeneracies in planets. This is because oxygen compounds have a tendency to be more concentrated in a planet’s center than its periphery. Consequently, a planet’s atmosphere has a higher pressure than its surface, thus preventing large-scale convection from occurring.


The physics of planet formation has long been a puzzle, but one recent discovery may help explain it. A collision between two bodies that are similar in size can create enough energy to vaporize a significant amount of material. These planetary bodies then collide again, eventually cooling down into spherical bodies. Collisions are a common way for planets to form. They are also responsible for many features of our own solar system.

A collision between two objects with similar masses may result in an unstable density gradient and disrupt the crystallization of magma oceans. One Martian researcher, Linda Elkins-Tanton, found that a hit-and-run collision caused the Martian magma ocean to overturn. Then, continued crystallization of the molten rock would produce a new density gradient atop the newly rearranged pile.

In the past, scientists had assumed that the Earth and Moon formed through violent head-on collisions. However, recent research shows that the collision angle was more likely direct than 45 degrees. If this were the case, then Earth and the Moon would have formed 150 million years later than previously thought. A collision of this size and speed would not remove the tungsten that made the Earth and Moon so different. It would be much harder to get the moon to come into its own.

Solar wind

Solar wind is a stream of charged particles from the Sun’s upper atmosphere. It is mostly made up of electrons, protons, and alpha particles, but also contains trace amounts of other atomic nuclei, heavy ions, and rarer traces. This plasma travels through space superimposed with the interplanetary magnetic field. During the process of making planets, solar wind is constantly changing in density, temperature, and speed.

The planetary atmospheres are largely unaffected by solar wind, except for Mercury, which bears the full brunt of the solar wind. Mercury has a transient atmosphere, but its intrinsic magnetic field prevents solar wind particles from penetrating its magnetosphere. The solar wind particles only reach the cusp regions of Mercury, and during coronal mass ejections, the magnetopause is pressed into the surface. In such a scenario, solar wind particles interact freely with the planetary surface.

The solar wind has a huge effect on comet tails, so much so that it can be measured with spacecraft. Its speed is around 400 kilometers per second near Earth’s orbit. It is thought to be a roughly circular boundary between the solar system and the interstellar medium. This boundary is outside of Pluto’s orbit and is located at the edge of the Sun’s influence. In October 2008, NASA’s Interstellar Boundary Explorer mission launched a mission to probe the boundary between Pluto’s orbit and the heliopause.