Voyager May Be at End of Solar System

very very cool! I wonder how long it takes messages/commands to go between the JPL and Voyager 1.

Probing The Outer Reaches Of Your Puffy Bubble
Probing The Outer Reaches Of Your Puffy Bubble Hello from the children of planet Earth. Come in, anything. Who wants pie?
(Associated Press)
Mark Morford
http://sfgate.com/cgi-bin/article.cgi?f=/n/a/2003/11/05/state1544EST0083.DTL&nl=fix

The aging Voyager 1 spacecraft, the most distant human-made object, is poised to leave the puffy bubble that envelops our solar system for the uncharted frontiers of interstellar space, scientists said Wednesday.

As of Wednesday, 26 years after its launch, the robotic spacecraft was 8.4 billion miles from the sun. That's 90 times the distance separating the Earth from our star.

As Voyager 1 continues to push far beyond the orbits of the nine planets, mission scientists disagree whether it temporarily passed into the region of space where the sun's sphere of influence begins to wane and the solar system comes to an end.

They do agree that the 1-ton probe is giving the first glimpse of what lies beyond our galactic neighborhood, from where it sits on an arm of the spiraling Milky Way.

"It's like we're piercing a hole in the curtain that separates us from the rest of the galaxy," Merav Opher, a research scientist at the National Aeronautics and Space Administration's Jet Propulsion Laboratory, said during a news conference broadcast from NASA headquarters in Washington, D.C.

The sun casts off highly charged particles, called the solar wind, that stream out to form a vast bubble around our solar system. It's akin to the atmosphere that cocoons the Earth.

Beyond the bubble's ever-shifting boundary, called the termination shock, lies a region where particles cast off by dying stars begin to hold sway, and interstellar space begins. The region has never been probed in 40 years of space exploration.

Whether Voyager 1 reached that first boundary or is still on approach remains unclear. On Wednesday, scientists provided evidence for both possibilities. Further details appear Thursday in the journal Nature.

"This is very exciting: Voyager is beginning to explore the final frontier of our solar system," said Edward Stone, the Voyager project scientist. "It's a totally new region we've never been in before."

Scientists have long theorized that a shock wave exists where the hot solar wind bumps up against the thin gas of the interstellar medium. A similar shock wave precedes aircraft flying faster than the speed of sound, causing a sonic boom.

One team suggests Voyager 1 temporarily reached the termination shock in August 2002. Six months later, the heliosphere apparently puffed back out, placing the probe back within the bounds of the solar system, scientists said.

A second team believes Voyager 1 is merely at the threshold of the termination shock. The region is abuzz with high-energy particles but poses no risk to the spacecraft, scientists said.

Further observations from the spacecraft -- as well as Voyager 2, which trails its faster twin -- should resolve the dispute as it pushes farther into space.

"It's just a matter of time," said Frank McDonald, of the University of Maryland.

The nuclear-fueled Voyager 1 and 2 both should remain operational to 2020. That would be long enough for Voyager 1 to pass the termination shock, traverse an intermediate zone called the heliosheath and enter interstellar space, all while continuing to beam data back to Earth with its 20-watt transmitter.

"Voyager 1 will become our first interstellar probe," Stone said. "The only question is, will we get there while we still have electrical power. So we're in a race."

Voyager 1 and 2 both carry a 12-inch, gold-plated phonograph record containing a variety of sounds, images, printed messages, musical selections and spoken greetings in 55 languages.

"Hello from the children of planet Earth," is one of the greetings.

good old voyager