A new study based on peculiar class of meteorites sheds light on the timeline of Jupiter’s formation and how it may have wandered through the Solar System.
Researchers at Brown University have revealed through their findings that Jupiter possibly was formed closer to the Sun and over the years migrated outwards and settled in its current orbit. While the study doesn’t preclude other migration scenarios, it does provide strong constraints on the timing of Jupiter’s presence in the inner solar system.
For their study researcher resorted to a particularly rare kind of meteorites – CB chondrites – that belong to a class of most common meteorites found on Earth – chondrites. While chondrites are common, CB chondrites are very rare and contain metallic grains that appear to have been condensed directly from vaporized iron. Authors of the study published in journal Science Advances point out the thing that makes CB chondrites so interesting: The chondrules of CB chondrites all date back to a very narrow window of time in the early solar system.
To vaporize iron in celestial bodies a particular level of impact speed is required – at least 20 kilometers per second. Traditional computer models of early solar system only produce impact speeds of around 12 kilometers per second at the time when the CB chondrites were formed and this effectively means that there is something missing.
Further, studies have hinted that CB chondrites were formed as objects in the early solar system and that too within the present day asteroid belt when objects in Solar System crashed into each other at incredible speeds – at hypervelocity.
Authors of the latest study came up with new computer simulations to show that Jupiter’s immense gravity would have provided the right conditions for these hypervelocity impacts to occur. That in turn suggests that Jupiter was near its current size and sitting somewhere near the asteroid belt when the CB chondrules were formed, which was about 5 million years after formation of the first solar system solids.
The scenario, known as the Grand Tack (a term taken from sailing), suggests that Jupiter formed somewhere in the outer solar system. But as it accreted its thick atmosphere, it changed the distribution of mass in the gassy solar nebula surrounding it. That change in mass density caused the planet to migrate, moving inward toward the sun to about where the asteroid belt is today. Later, the formation of Saturn created a gravitational tug that pulled both planets back out to where they are today.