A new research that was published in the magazine Nature Astronomy might give us some clues on how the largest planet in our Solar System, Jupiter, was formed. For decades, this was a commonly discussed subject amongst scientists, as the formation mechanism of the planet that has 300 times the mass of Earth was still not understood.
So how was Jupiter formed?
Several astrophysicists have united their forces in order to decipher the mysteries about how Jupiter was created. Yann Alibert, who is a Science Officer of the Swiss National Centre of Competence in Research (NCCR) PlanetS and the lead author of the paper, explained how the giant planet was formed. It appears that at the beginning, during the first one million years, tiny pebbles with the size of a centimeter gathered and created a core. Later on, throughout the next two million years, an accretion of larger rocks, planetesimals, having the size of a kilometer, took place.
According to Alibert, “during the first stage the pebbles brought the mass”, however, it seems that “in the second phase, the planetesimals also added a bit of mass, but what is more important, they brought energy.” Three million years later, Jupiter had expanded to a mass of 50 Earths and then later the gas runaway accretion continued, which led to the gas giant that has now a mass 300 times bigger than that of our planet.
A delayed growth involved in the formation of Jupiter
Julia Venturini, who is a postdoc at the University of Zürich, mentioned that the question that motivated the research was: how was it possible for Jupiter to have grown from 20 to 50 Earth masses in two million years? Following the calculations of the researchers, it was established that the time the young Jupiter had a mass of 15 to 50 Earths was longer than it was formerly believed. The astrophysicists mentioned that during this formation stage, the collisions with the large rocks generated sufficient energy to heat the gaseous atmosphere of the young planet, thus preventing the rapid cooling, contraction and a future gas accumulation. This is how the gas accretion was delayed.