Turbulence is crucial to planet formation, reveals study

Turbulence is crucial to the formation of new planets, scientists from the Max Planck Institute for Astronomy, Germany, have said.

Washington, Sept 5 : Turbulence is crucial to the formation of new planets, scientists from the Max Planck Institute for Astronomy, Germany, have said.

Study leader Anders Johansen said such turbulence is vital in helping planets go from "toddler" to "teenage" size by helping rocks and boulders stick together.

Johansen said this is a turnaround from several years ago, when scientists considered turbulence a destructive obstacle for newly forming planets.

He, however, said though a few scientists recently suspected that turbulence might help in planet formation, till now, no one had showed in detail how that might work.

"We were the first to model how interacting boulders move around in this turbulence," said Johansen.

Johansen said their research showed that turbulence could create "planetesimals", or planetary precursors, very quickly - in only seven orbits around a star, or around just a hundred years.

As the matter swirl around, microscopic bits of dust hit each other and stuck together. Gradually they gathered into rocks and boulders, sometimes around a yard across, Johansen said.

"We have a pretty good grasp of this [process]," he said.

He, however, said that explaining how matter formed bigger clumps - up to planetesimals about a kilometre across - was something that had eluded scientists even now.

"That has been known to be a big problem for the last 30 years. Part of the issue is that when larger boulders collide with each other, they don't stick to each other very well, but are likely to destroy each other when they collide," said Johansen.

"Around this size, the rocks would begin to experience drag from the gas around them. Eventually the rocks would lose so much energy that they would spiral into the star, crashing to a fiery death," he said.

In the new computer model, the scientists studied what would happen if this disk of orbiting matter did not spin calmly around but instead had turbulence stirring things up.

The simulation revealed that the turbulence had high-pressure areas where boulders tended to accumulate.

Once a few boulders get stuck together in such locations, the formation helped other boulders stick too, as they shielded each other from the gas, the findings revealed.

These areas also helped the boulders resist the headwind from the gas around them, like "drafting" racers, Johansen said.

Though Johansen and his team of scientists haven't figured out for sure what might cause such turbulence, they're confident that there would be a fair amount of it in the disks surrounding young stars.

The study appears in last week's issue of the journal Nature, reports National Geographic.

ANI