Because the vast majority of gas giant planets are generally found quite close to their respective suns, it has been assumed that Jupiter, too, also formed near the sun. However, new research has revealed that Jupiter is now thought to have originated at a much greater distance from the sun than originally thought.
As Phys.org reports, scientists from Lund University have conducted a series of computer simulations which indicate that Jupiter began its life 4.5 billion years ago — at a distance that is four times farther from the sun than its present location would suggest.
“This is the first time we have proof that Jupiter was formed a long way from the sun and then migrated to its current orbit. We found evidence of the migration in the Trojan asteroids orbiting close to Jupiter,” Lead author Simona Pirani, who is a doctoral student in astronomy at Lund University, explained.
The Trojan asteroids are made up of thousands of different asteroids that have been categorized as belonging to two distinct groups. These asteroids are located roughly the same distance away from the sun as from Jupiter.
With these asteroids engaged in their respective orbits near Jupiter, scientists have discovered that a much larger number of the Trojan asteroids can be found in front of Jupiter, rather than behind it. This surprising asymmetry, according to the new study, has allowed scientists to learn more than ever before about the spatial migration of this planet.
— Phys.org (@physorg_com) March 25, 2019
“The asymmetry has always been a mystery in the solar system. We can learn a lot about Jupiter’s core and formation from studying the Trojans,” Anders Johansen, a professor of astronomy at Lund University, noted.
Due to the confusion revolving around this asymmetry, scientists have previously been baffled as to why the two groups of Trojan asteroids each hold a different number of asteroids within them. However, the latest research into Jupiter’s origin has shed more light on this mystery, and scientists have been able to use computer simulations to understand that, as Jupiter migrated through the solar system, it began to slowly draw closer these asteroids — creating the asymmetry that we see today.
Because this asymmetry could only have occurred if Jupiter began its life farther out in the solar system — only migrating to its present position over a period of approximately 700,000 years — scientists have learned that, as Jupiter drew closer to the sun, its enormous gravity drew more asteroids in front of it. This resulted in a much smaller number of asteroids being scattered behind the gas giant.
Computer simulations have further suggested that Jupiter began to draw in Trojan asteroids long before the planet developed a gas atmosphere, when it was still relatively young.
The new study which has determined the migration pattern of Jupiter through the solar system by tracking the Trojan asteroids has been published in Astronomy & Astrophysics.