Of all the planets in our Solar System, Jupiter is the oldest says an international team of scientists based on their study wherein they looked at tungsten and molybdenum isotopes on iron meteorites.
According to the team of scientists at Lawrence Livermore National Laboratory and Institut für Planetologie at the University of Münsterin Germany, meteorites are made up of two genetically distinct nebular reservoirs that would have coexisted in our Solar System from the very beginning – soon after our Solar System was formed.
Scientists say that the most plausible explanation behind this separation of two distinct nebular reservoirs is the possibility that Jupiter was formed soon after Solar System was formed – between 1 and 4 million years after the Solar System formation – and this effected left a gap in the disc (a plane of gas and dust from stars) and preventing the exchange of material between the two reservoirs.
In the study published in Proceedings of the National Academy of Sciences scientists have claimed that Jupiter is the oldest planet of 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.
Jupiter is the most massive planet of the solar system and its presence had an immense effect on the dynamics of the solar accretion disk. Knowing the age of Jupiter is key for understanding how the solar system evolved toward its present-day architecture. Although models predict that Jupiter formed relatively early, until now, its formation has never been dated. Scientists point out that they haven’t got any samples from Jupiter for their study and hence the next best possible evidence to go by is to rely on use isotope signatures of meteorites.
The team showed through isotope analyses of meteorites that Jupiter’s solid core formed within only about 1 million years after the start of the solar system history, making it the oldest planet. Through its rapid formation, Jupiter acted as an effective barrier against inward transport of material across the disk, potentially explaining why our solar system lacks any super-Earths (an extrasolar planet with a mass higher than Earth’s).
The team found that Jupiter’s core grew to about 20 Earth masses within 1 million years, followed by a more prolonged growth to 50 Earth masses until at least 3-4 million years after the solar system formed.