Craters on Vesta and Ceres could pinpoint Jupiter's age

Washington, September 14 (ANI): A new study that models the cratering history of Vesta and Ceres, which are the largest two objects in the asteroid belt, could help pinpoint when Jupiter began to form during the evolution of the early Solar System.

The study, carried out by scientists at the Italian National Institute for Astrophysics in Rome, explored the hypothesis that one or both objects formed during Jupiter's formation by modeling their cratering histories during the birth of the giant planet.

Their simulation described Jupiter's formation in three stages: an initial accretion of its core followed by a stage of rapid gas accretion.

This is, in turn, followed by a phase where the gas accretion slows down while the giant planet reaches its final mass.

During the last two phases, Jupiter's gravitational pull starts to affect more and more distant objects.

For each of these phases, the team simulated how Jupiter affected the orbits of asteroids and comets from the inner and outer Solar System, and the likelihood of them being moved onto a collision path with Vesta or Ceres.

According to Dr. Diego Turrini, who presented the results of the study at the European Planetary Science Congress in Potsdam, Germany, "We found that the stage of Jupiter's development made a big difference on the speed of impacts and the origin of potential impactors."

"When Jupiter's core approaches its critical mass, it causes a sharp increase in low-velocity impacts from small, rocky bodies orbiting nearby to Vesta and Ceres which lead to intense and uniform crater distribution patterns. These low-speed collisions may have helped Vesta and Ceres gather mass," he said.

"Once Jupiter's core has formed and the planet starts to rapidly accrete gas, it deflects more distant objects onto a collision course with Ceres and Vesta and the impacts become more energetic," he added.

The third stage of Jupiter's formation is complicated by a period known as the Late Heavy Bombardment, which occurred around 3.8 to 4.1 billion years ago.

During this time, a significant number of objects, rich in organic compounds, from the outer Solar System were injected on planet-crossing orbits with the giant planets and may have reached the Asteroid Belt.

In addition, Jupiter is thought to have migrated in its orbit around this time, which would have caused an addition flux of impactors on Vesta and Ceres.

The team will have an opportunity to confirm their results when NASA's Dawn space mission reaches Vesta in 2011 and then flies on for a further rendezvous with Ceres in 2015. (ANI)