Giant Ribbon Discovered at Edge of Solar System

NASA’s IBEX (Interstellar Boundary Explorer) spacecraft has made the first all-sky maps of the heliosphere and the results have taken researchers by surprise. The maps are bisected by a bright, winding ribbon of unknown origin.


Giant Ribbon Discovered at Edge of Solar System
By Dr. Tony Phillips


15 Oct 09 – (Excerpts) – For years, researchers have known that the solar system is surrounded by a vast bubble of magnetism. Called the “heliosphere,” it springs from the sun and extends far beyond the orbit of Pluto, providing a first line of defense against cosmic rays and interstellar clouds that try to enter our local space. Although the heliosphere is huge and literally fills the sky, it emits no light and no one has actually seen it.

Until now.

NASA’s IBEX (Interstellar Boundary Explorer) spacecraft has made the first all-sky maps of the heliosphere and the results have taken researchers by surprise. The maps are bisected by a bright, winding ribbon of unknown origin.

“This is a shocking new result,” says IBEX principal investigator Dave McComas of the Southwest Research Institute. “We had no idea this ribbon existed–or what has created it. Our previous ideas about the outer heliosphere are going to have to be revised.”Although the ribbon looks bright in the IBEX map, it does not glow in any conventional sense.

The ribbon is not a source of light, but rather a source of particles–energetic neutral atoms or ENAs.The ribbon also has fine structure–small filaments of ENA emission no more than a few degrees wide: larger image. The fine structure is as much of a mystery as the ribbon itself, researchers say.

One important clue: The ribbon runs perpendicular to the direction of the galactic magnetic field just outside the heliosphere.”That cannot be a coincidence,” says McComas.

But what does it mean? No one knows. “We’re missing some fundamental aspect of the interaction between the heliosphere and the rest of the galaxy. Theorists are working like crazy to figure this out.””Understanding the physics of the outer heliosphere is important because of the role it plays in shielding the solar system against cosmic rays.

(Mutation-causing cosmic rays, I might add.)

“The heliosphere’s size and shape are key factors in determining its shielding power and, thus, how many cosmic rays reach Earth.”

Author: Dr. Tony Phillips |Credit: Science@NASA

http://science.nasa.gov/headlines/y2009/15oct_ibex.htm?friend

Thanks to Icewoman for this link


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