Chinese scientist and team strike new path to explain how giant planets found their orbit
- Mechanism proposed by Zhejiang University scientist Liu Beibei and team in Nature journal may be ‘one of the missing links in solar system history’, says reviewer
- New model explains why the Earth’s formation was not affected by the migration of giant planets Jupiter, Saturn, Uranus and Neptune billions of years ago, says Liu
An international team of researchers has challenged the mainstream theory of when and how the giant planets in the solar system migrated to their present-day orbits.
In a paper published in Nature on Wednesday, they proposed a new theory that could dramatically move the timeline to as early as 5 million years after the solar system was born, instead of hundreds of millions of years afterwards.
“The proposed mechanism may be one of the missing links in solar system history,” one of the paper’s reviewers wrote.
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New giant-planet study better explains the formation of our galaxy, says lead author
The story of our solar system started 4.6 billion years ago when a gigantic molecular cloud contracted under its own gravity. The nascent sun rose from the hot, dense centre, while planets took shape around it in a swirling disk made of gas and dust particles.
Among the different types of planets that later formed, “the giant planets are so massive that they had huge impacts on the terrestrial planets and the evolution of the solar system itself,” said the paper’s lead author Liu Beibei from Zhejiang University in eastern China.
It is believed that as Jupiter, Saturn, Uranus and Neptune grew larger, they migrated towards the sun and reached a stable state where their orbits were much closer to the sun and to each other than they are today. This difference led scientists to look for possible mechanisms that disrupted the stability and brought the planets to their current positions.
The most popular theory, called the Nice model, posits that the instability occurred because of interactions between the giant planets and smaller solid objects beyond Neptune’s orbit, and that the process took a few hundred million years to complete.