Voyagers Find Giant Jacuzzi-like Bubbles at Edge of Solar System

http://www.universetoday.com/86446/voyagers-find-giant-jacuzzi-like-bubbles-at-edge-of-solar-system/

Voyagers Find Giant Jacuzzi-like Bubbles at Edge of Solar System
by Nancy Atkinson on June 10, 2011

The barrier at the edge of our solar system may not be the smooth shield that scientists once thought. The venerable Voyager spacecraft have detected a huge, turbulent sea of magnetic bubbles in the heliosheath — the interface between the heliosphere and interstellar space — similar to an actively bubbling Jacuzzi tub. At a briefing today, scientists said the finding is significant as “we now will have to change our view of how the sun interacts with the solar system,” said Arik Posner, Voyager program scientist at NASA Headquarters. But it also means that the “force field” that surrounds the entire solar system may be letting in more harmful cosmic rays and energetic particles than previously thought.

Over 30 years into their mission, the Voyagers are still monitoring their environment and sending back data. In 2007, scientists noticed that Voyager 1 recorded dramatic dips and rises in the amount of electrons it encountered as it traveled through the heliosphere, the barrier that surrounds the entire solar system and is created by the sun’s magnetic field. Voyager 2 made similar observations of these charged particles in 2008.

Using a new computer model to analyze the data, scientists found the sun’s distant magnetic field is likely made up of bubbles approximately 100 million miles (160 million kilometers) wide — “like long sausages,” said Merav Opher at the briefing, an astronomer at Boston University who is the lead author of a paper published in the Astrophysical Journal.

And the bubbles are moving around, with oscillations of plus or minus 10 to 20 km. “It is very bubbly as far as we can tell,” Jim Drake from the University of Maryland said at the press conference. “The entire thing is bubbly, like where the jets come out from a Jacuzzi.”

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