A new study, published in the Proceedings of the National Academy of Sciences, reveals that Jupiter may be the oldest planet in the solar system. The latest research states that the gas-giant planet might have formed just a million years after Sun, which means Jupiter is approximately 50 million years older compared to Earth.
The study was carried out by an international group of researchers from Lawrence Livermore National Laboratory (LLNL) and Institut fur Planetologie at the University of Munster in Germany. They revealed that they used isotope signatures of meteorites to conclude the age of the planet as they did not have the lack of Jupiter.
"We do not have any samples from Jupiter, in contrast to other bodies like the Earth, Mars, the moon and asteroids," Thomas Kruijer, the lead author of the paper and a researcher at LLNL, stated in a press release.
A report by Popular Mechanics revealed that the space rock samples that were examined by the researchers could be grouped into two different isotope signatures. The meteorite samples were formed in two different types of clouds comprising of dust and gas due to their different composition. These clouds remained separated between 1 million and 3-4 million years after the solar system formed.
The team of researchers showed that the formation of Jupiter was the source of these two different sources of meteorites. The newly-formed planet had then cleared a path through the debris surrounding Sun.
The scientists demonstrated through their models and said that these two distinct sources of meteorites came from the formation of Jupiter. The new planet then cleared the accretion disk, a path through dust and debris that surround Sun.
According to reports, the birth of Sun took place around 4.6 billion years ago as per the evolution timeline of the solar system. The Sun was surrounded by the accretion disk comprising of ice, gas and rock. The rocky core of gas-giant Jupiter was formed just around a million years after Sun's first light, which cut a gap in the accretion disk following its orbit.
After Jupiter evolved, the formation of more planets started taking place just like the space rocks in the inner and outer parts of the disk. The asteroids that were formed beyond Jupiter around 4.5 billion years later were shoved into the asteroid belt by gas giants and then collided with each other.
When the bits of these space rocks started shattering, some of them reached Earth and were examined by the scientists.
"Jupiter is the oldest planet in the solar system, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation," Kruijer said.
Saturn involved the growth of large solid cores of about 10 to 20 Earth masses, followed by the accumulation of gas onto these cores. So, the conclusion was the gas-giant cores must have formed before dissipation of the solar nebula, the gaseous circumstellar disc surrounding the young Sun, which occurred between 1 million years and 10 million years after the solar system formed.
"Our measurements show that the growth of Jupiter can be dated using the distinct genetic heritage and formation times of meteorites," Kruijer added.
