A new study indicates that the gas giant Jupiter is not only the biggest planet but also the oldest planet in the Solar System. Its core had already developed to be 20 times more massive than the planet Earth just 4 million years after the Sun was formed.
The findings of the study were reported in the Proceedings of the National Academy of Sciences on Monday. The study was led by Thomas Kruijer of the University of Münster in Germany and Lawrence Livermore National Laboratory in California and other colleagues, according to Space.com.
Kruijer said that Jupiter is the oldest planet of the solar system and its solid core shaped well before the solar nebular gas dissipated, consistent with the core-accretion model for giant planet formation. He added that it is the first time they can say something about Jupiter based on measurements done in the lab.The researchers probe the creation of Jupiter by analyzing the ages of iron meteorites that have fallen on Earth.
The solar system started as a disk of dust and gas about 4.6 billion years ago. It was then followed by the planets, first was the gas giants then by the rock-and-metal terrestrial planets just like the Earth. Among them is the planet Jupiter, which is the most massive. This gas giant is also over 300 times the mass of the Earth. With this finding, the scientists speculated that Jupiter was the oldest that could dip more material from the disk before other younger planets appeared, according to The Washington Post.
They also discovered that when the solar system was about 4 million years old. The gravity of Jupiter that is so powerful prevents rocks from crossing beyond its orbit. It became a blockade to protect the inner solar system from the meteorites.
Then, Jupiter developed to about 50 Earth masses and headed toward the Sun when the solar system was about 4 million years old. This allows the outer asteroids to merge with inner rocks. Currently, they are now in a single belt that exists between Jupiter and Mars. Meanwhile, the rocks from this merging go ashore on the planet Earth.
Kruijer said that their measurements show that the growth of Jupiter could be dated by utilizing the distinct genetic heritage and formation times of meteorites. This discovery could aid in understanding why the solar system lacks worlds intermediate in mass between Earth and the ice giants like Uranus and Neptune.