London, Feb 26 A new simulation has suggested that the asteroid belt that scientists see today may have been shaped by Jupiter and Saturn migrating from their original orbits during a tumultuous period in the early solar system.
According to a report in New Scientist, the work could help refine a picture of how quickly the planets moved and where they got their start.
Recent studies have suggested that many objects in the solar system were reshuffled nearly 4 billion years ago.
Jupiter, Saturn, Uranus, and Neptune, are thought to have been born close together before gravitational interactions with numerous pieces of rocky debris changed their trajectories.
Their movement then caused the rocky debris to scatter like bowling pins, potentially explaining what battered the Earth, Moon, and Mars with so many craters some 3.8 billion years ago.
Now, this same reshuffling might explain the appearance of the main asteroid belt between Mars and Jupiter.
Several grooves in the belt seem to be empty of asteroids. Called Kirkwood gaps, they are thought to be cleared of debris by Jupiter's gravity, which causes any objects orbiting there to move chaotically.
Saturn's moons have produced similar gaps in the planet's rings.
David Minton and Renu Malhotra at the University of Arizona in Tucson decided to reproduce the asteroid belt and its gaps in a computer simulation.
Using the current orbits of the giant planets Jupiter, Saturn, Uranus, and Neptune, the team was able to roughly replicate the observed distribution of asteroids over a simulated period of some 4 billion years.
The four planets are thought to have started out relatively close together. Then, Jupiter moved inward while Saturn, Uranus and Neptune moved outward.
"We're able to produce an asteroid belt that's much more like the observed asteroid belt than a model that only uses the giant planets in their current positions," Minton said.
In this version of the simulation, two of the belt's gaps showed a distinct signature: a sharp inner edge and a smeared out, relatively empty outer edge.
That is what would be expected if Jupiter carved the gaps as it migrated towards the Sun.
"In that case, the gaps' inner edges represent where Jupiter stopped in its migration," said Minton.
Such a gap "profile" is a closer match to the observed asteroid distribution than the team's other simulation using the planets' current orbits, he added.
Saturn's outward migration also seems to have left its imprint on the asteroid belt. But, in Saturn's case, it was on the inner edge of the entire belt - not the gaps. (ANI)
