Has Voyager 1 left the solar system?

    Scientific confusion was the order of
the day on Wednesday following a
report that suggested a 35-year-old
space probe had become the first
human-made object to make it
beyond our solar system.
    New Mexico State University
astronomer W.R. Webber reported in
a paper published online by the
American Geophysical Union that the
spacecraft had made it beyond the
influence of the sun because Voyager
1 had measured a drastic change in
radiation levels last Aug. 25.
    But no sooner had that report
appeared than NASA said it begged to
differ with any interpretation that
suggested that its spacecraft had
definitely left the solar system.
     "The Voyager team is aware of reports
today that NASA's Voyager 1 has left
the solar system," said Edward Stone,
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."
    Stone said the Voyager team reported
last December that Voyager 1 was
within a 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,"
Stone said.
    The American Geophysical Union
subsequently revised the "left-the-
solar-system" headline on its news
release with a less dramatic one that
said Voyager 1 had "entered a new
region of space."
    Webber's research suggested that
when the spacecraft was roughly 18
billion kilometres from the sun last
Aug. 25, it suddenly nearly stopped
detecting "anomalous" cosmic rays.
That is a type of radiation trapped in
the outer part of the heliosphere, the
vast "bubble" of space affected by the
sun's magnetic field, which encloses
the solar system.
    Meanwhile, he said the spacecraft had
detected record levels of "galactic"
cosmic rays, radiation that comes
from outside the solar system.
    Webber said it's not clear whether
Voyager 1 has actually entered
interstellar space or some other zone
beyond the solar system.
    "It's outside the normal heliosphere, I
would say that," Webber said in a
statement. "We're in a new region.
And everything we're measuring is
different and exciting."