A new study reveals that Jupiter may have likely formed only a million years after the Sun. By that calculation, it seems that the great gas giant is around 50 million years older than Earth.
An international team of scientists from Lawrence Livermore National Laboratory noted in a paper published in the Proceedings of the National Academy of Sciences that they did not have samples from Jupiter, so they used isotope signatures of meteorites to infer the planet's age. Their findings presented a clear line of deduction, identifying Jupiter as the oldest planet in the solar system.
In an explanation from Popular Mechanics, the meteorite samples that were analyzed fell into two different groups with different isotope signatures. The difference in their composition indicated that these meteorites were formed in two distinct clouds of gas and dust and that they surrounded the Sun but separated from each other. Through their models, the team from LLNL demonstrated that these two distinct sources of meteorites came from the formation of Jupiter. The new planet then cleared a path through the dust and debris that surrounded the Sun.
The evolution timeline of the solar system put the birth of the Sun around 4.6 billion years ago. At the time, it was surrounded by an accretion disk of gas, ice and rock. As the first planet in the solar system, the rocky core of Jupiter formed only about 1 million years after the Sun's first light, cutting a gap in the accretion disk and following its orbit.
As Jupiter grew, more planets began to form, as did asteroids in both the inner and outer parts of the disk. Some 4.5 billion years later, the asteroids that formed beyond Jupiter were shoved into the asteroid belt by gas giants and then collided with each other. As bits started breaking off, some of them reached the Earth as meteorites, and they get analyzed by scientists.
More work needs to be done to confirm such theory. But without a doubt, Jupiter is the oldest planet in the solar system.