Voyager 2 Proves Solar System Is Squashed

[link to www.nasa.gov]

Briefing:

"SAN FRANCISCO, Calif. - NASA's Voyager 2 spacecraft has followed its twin, Voyager 1, into the solar system's final frontier, a vast region at the edge of our solar system where the solar wind runs up against the thin gas between the stars.

However, Voyager 2 took a different path, entering this region, called the heliosheath, on Aug. 30, 2007. Because Voyager 2 crossed the heliosheath boundary, called the solar wind termination shock, about 16 billion kilometers (10 billion miles) away from Voyager 1 and almost 1.6 billion kilometers (a billion miles) closer to the sun, it confirmed that our solar system is "squashed" or "dented"- that the bubble carved into interstellar space by the solar wind is not perfectly round. Where Voyager 2 made its crossing, the bubble is pushed in closer to the sun by the local interstellar magnetic field.

"Voyager 2 continues its journey of discovery, crossing the termination shock multiple times as it entered the outermost layer of the giant heliospheric bubble surrounding the sun and joined Voyager 1 in the last leg of the race to interstellar space," said Voyager Project Scientist Edward Stone of the California Institute of Technology, Pasadena, Calif. Results on the Voyager 2 shock crossing from the entire Voyager science team are being presented at the Fall 2007 meeting of the American Geophysical Union in San Francisco.

The solar wind is a thin gas of electrically charged particles (plasma) blown into space by the sun. The solar wind blows in all directions, carving a bubble into interstellar space that extends past the orbit of Pluto. This bubble is called the heliosphere, and Voyager 1 was the first spacecraft to explore its outer layer, when it crossed into the heliosheath in December 2004. As Voyager 1 made this historic passage, it encountered the shock wave that surrounds our solar system called the solar wind termination shock, where the solar wind is abruptly slowed by pressure from the gas and magnetic field in interstellar space."