Voyager Exits Solar System. Really? Not so Fast

The American Geophysical Union published an article on Wednesday which boldly announced that NASA's Voyager 1 had left our Solar System.

But before humanity could celebrate this unprecedented accomplishment, NASA came in and threw water into the fire. About three hours after the AGU articles was published, the National Aeronautics and Space Agency released a statement denying the claims.

And it was noone other than Edward C. Stone, the Voyager project scientist, who came forth and with the disclaimer.

"The Voyager team is aware of reports today that NASA's Voyager 1 has left the solar system," said Stone, a veteran Voyager project scientist based at the California Institute of Technology, Pasadena, Calif.

"It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space. In December 2012, the Voyager science team reported that Voyager 1 is within a new region called 'the magnetic highway' where energetic particles changed dramatically. A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space and that change of direction has not yet been observed."

It all started when William R. Webber of New Mexico State University and Frank B. McDonald of the University of Maryland reported that on Aug. 25 last year, the Voyager had observed a sudden change in the mix of cosmic rays hitting it.

Instruments onboard of the spacecraft had recorded nearly a doubling of cosmic rays from outside the solar system, while the intensity of cosmic rays that had been trapped in the outer solar system dropped by 90 percent.

According to Stone, the critical indicator of Voyager have left the Solar System would be a change in the direction of the magnetic field, not cosmic rays, for marking the outermost boundary of the solar system.

In their paper, Dr. Webber and Dr. McDonald (who died only six days after Voyager observed the shift in cosmic rays) did not claim that Voyager 1 was in interstellar space, but had entered a part of the solar system they called the “heliocliff.” The geophysical union then sent out another e-mail with the same article but a milder headline: “Voyager 1 has entered a new region of space.”

Voyager was launched in 1977 on a grand tour of the outer planets, and it is now nearly 11.5 billion miles from the Sun, speeding away at 38,000 miles per hour.