Solar system edge 'bunches' in magnetic bubbles

A pair of NASA probes wandering in deep space have discovered that the outer edge of the solar system contains curious magnetic bubbles and is not smooth as previously thought, astronomers said Thursday.

Two NASA Voyager spacecraft, which launched in 1977, are currently exploring the furthest outlays of the heliosphere, where solar wind is slowed and warped by pressure from other forces in the galaxy, the U.S. space agency said.

"Because the sun spins, its magnetic field becomes twisted and wrinkled, a bit like a ballerina's skirt," said astronomer Merav Opher of Boston University. "Far, far away from the sun, where the Voyagers are, the folds of the skirt bunch up."

The Voyagers are almost 16 billion kilometers from Earth in a little-known boundary region where solar wind and magnetic field are influenced by "material expelled from other stars in our corner of the Milky Way galaxy," NASA said.

This "turbulent sea of magnetic bubbles" occurs when parts of the Sun's distant magnetic field break up and reorganize under pressure. The bubbles are giant - 160 million kilometers wide - meaning the Voyager probes could take multiple weeks to cross just one of them.

Scientists have previously theorized that the sun's distant magnetic field curved in a "relatively graceful arc, eventually folding back to rejoin the sun," NASA said. But images of a smooth outer heliosheath have now been discarded as scientists begin to realize that the region is actually bubbly and "frothy."


/Hurriyet Daily News/