http://www.theaustralian.news.com.au/story/0,25197,26217414-12377,00.html

A BRIGHT ribbon of hydrogen atoms marks the edge of the solar system, where the Sun's wind meets emissions from the rest of the galaxy, researchers reported.

They used telescopes aboard the orbiting Interstellar Boundary Explorer spacecraft or IBEX to look toward the heliopause, which is the boundary where solar wind meets galactic wind at the edge of the solar system beyond Pluto.

Researchers combined images from IBEX with data from the Cassini spacecraft, which is near Saturn, and said it completely altered their ideas about what this border area looked like.

"The IBEX results are truly remarkable, with emissions not resembling any of the current theories or models of this never-before-seen region," David McComas of the Southwest Research Institute in Texas said.

"We expected to see small, gradual spatial variations at the interstellar boundary, some ten billion miles (16 billion km) away.

"However, IBEX is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky."

It consists of hydrogen atoms that were once charged but which have been neutralised, they reported in five separate reports in the journal Science.

The researchers say the findings can tell them about the interstellar cloud through which our Milky Way galaxy is moving and which the galaxy will leave in about 10,000 years.