Latest research reveals that the growth of Jupiter faced a delay of 2 million years.

Jupiter is the largest planet of our solar system. It is the 3^rd brightest natural object that we can observe in the night sky. The term ‘gas giant’ is used to refer Jupiter because gases like Hydrogen and Helium constitute the majority of its atmosphere. Significant turbulence and massive storms are quite common in the atmosphere of this gas giant and the ‘Great Red Spot’ is the most popular of all. According to astronomers, this gigantic storm is at least as old as the 17^th century when it was observed for the first time through a telescope.

This giant ball of gas has a diameter of 142,984 kilometers at its equator. Three-fourths of the planet’s atmosphere is made up of Hydrogen while Helium accounts for 24%. A variety of elements fill the remaining 1% of the atmosphere. Some common commodities in that list include Methane, Oxygen, Carbon, Hydrogen Sulfide, Neon, and Ammonia. The concentration of these materials increases towards the inner atmosphere of the gas giant. On the other hand, the concentration of Hydrogen becomes even more dominating once we move towards the outer atmosphere of the Jupiter.

Jupiter is 2.5 times heavier than all the other planets of our solar system combined. Comparing it to Earth, it is 318 times as massive as our planet. On the other hand, its density is much less than Earth primarily due to its humungous volume. Scientists estimate that the volume of Jupiter is equal to 1,321 Earths. However, the density of the Sun is comparable to the Jupiter’s. The fact that Jupiter has 79 moons itself explains the vastness of this gas giant. The largest among them is Ganymede, whose diameter is more than that of the planet Mercury. Researchers were quite curious to figure out how this gigantic planet came into being and it seems as if they finally have got the answer to this long-lasting query.

The researchers of the University of Bern, ETH Zürich, University of Zürich, and the National Center of Competence in Research (NCCR) of Switzerland joined forces to make this amazing breakthrough. Julia Venturini, a Postdoc at the University of Zürich, mentioned that the largest planet of our solar system grew in phases. She said,

 “We could show that Jupiter grew in different, distinct phases.”

Similarly, Yann Alibert, the First Author of the paper who serves as a Science Officer at PlanetS, explained the growth disorders Jupiter faced. For the first million years, the core of the planet was created following the rapid accretion of small pebbles. After that, the ‘Planetesimals’ (kilometer-sized rocks) accreted for the next two million years. This is an extremely slow phase during which massive amounts of heat are released. Alibert referred to that by saying,

“During the first stage, the pebbles brought the mass. In the second phase, the planetesimals also added a bit of mass, but what is more important, they brought energy.”

At that time, the mass of the Jupiter was approximately equal to 50 Earths which grew rapidly in the third phase resulting in a gas giant having a mass of 318 Earths. All the information about this model of Jupiter’s growth came from the meteorites which were presented at a conference, last year. At first, Both Yann and Julia failed to understand the reasons behind the data of these meteorites but later research helped them to recognize this logic. Venturini acknowledged that in the following words:

“How could it have taken two million years for Jupiter to grow from 20 to 50 Earth masses? That seemed much too long. That was the triggering question that motivated our study.”

According to this theory, Jupiter acted as a hurdle during the second phase where the dust disk of the planet didn’t allow any pebbles from the outward regions to enter the interior parts. Alibert mentioned that a meeting between the experts of cosmochemistry, astrophysics, and hydrodynamics was held following a discussion through emails and it took them merely two hours to realize what they need to calculate. Their calculations at the NCCR clearly indicated that the time taken by the Jupiter to grow from 15 to 50 Earth masses was much more than previously assumed. The report published in the journal ‘Nature Astronomy’ sums it up beautifully by saying,

“Pebbles are important in the first stages to build a core quickly, but the heat provided by planetesimals is crucial to delay gas accretion so that it matches the timescale given by the meteorite data.”