Jupiter became the largest planet in the solar system due to the absorption of young planets. Scientists in a new study reached this conclusion. Details of the origin of the giant told them the first clear data on the chemical composition of Jupiter, hidden under a cloudy atmosphere.

Despite Jupiter being a giant planet, very little was known about its inner work. Swirling clouds from the upper atmosphere could be observed with the telescopes. They hindered the study of the planet itself.

In a new study, scientists were able to look under a dense cloud using gravitational data from NASA’s Juno spacecraft. These data allowed us to map the rock material of Jupiter’s nucleus, which revealed an unexpectedly large number of heavy elements. Based on the giant’s chemical composition, scientists have suggested that Jupiter absorbed young planets, or planetesimals, to support growth.

Jupiter is now mostly a gas sphere, but it was born like other planets in the solar system to build up rock material. As the planet’s gravity collected more and more rocks, its core became so dense that it began to attract large amounts of gas from a distance. For the most part, it was hydrogen and helium left over from the birth of the Sun that helped Jupiter form its vast gaseous atmosphere.

There are two theories as to where Jupiter got its original rock material. According to the first, the planet has collected billions of pieces of stone. The second theory is that Jupiter’s nucleus was formed by the absorption of many planetesimals, huge pieces of rock that could later become smaller planets like Earth or Mars.

“Juno provided very accurate gravity data that helped us to constrain the distribution of the material in Jupiter’s interior. This is unique data that could only be obtained from a spacecraft orbiting the planet,” said lead researcher astrophysicist Yamila Miguel.

A new study supports the second theory. Juno and its predecessor Galileo measured the gravitational field at various points around Jupiter. The data showed that the rock material in the planet has a high concentration of heavy elements that form dense clots, and therefore have a stronger gravitational effect than the gaseous atmosphere.

Growing ordinary pieces of stone, the planet would not be able to collect so many heavy elements. When Jupiter became large enough, the gas that gathered around it would prevent the addition of new stones. However, larger planetesimals could be attracted to the nucleus even despite the gas, its resistance was not enough to overcome the gravity acting on the young planets. According to researchers, only the simultaneous increase of rock material and gas could form modern Jupiter.